Back to Home Page of CD3WD Project or Back to list of CD3WD Publications

Home - English - French - German - Italian - Portuguese - Spanish
                            STORAGE METHODS
                             VOLUME III OF
                       SMALL FARM GRAIN STORAGE
                      CARL LINDBLAD, PEACE CORPS
                          LAUREL DRUBEN, VITA
                                            MANUAL SERIES NUMBER 35E
                   FIRST PRINTING    SEPTEMBER 1976
                   SECOND PRINTING,
                   IN THREE VOLUMES     JULY 1977
                   THIRD PRINTING       JULY 1980
                       1600 Wilson Boulevard, Suite 500
                         Arlington, Virginia 22209 USA
                       Tel:  703/276-1900 . Fax: 703./243-1865
                               TABLE OF CONTENTS
The Purpose of the Manual
The People Who Prepared This Manual
The Sponsoring Organizations
How To Use This Manual
Storage Principles
Finding a Good Storage Place & Illustrations
Cleaning and Repairing Your Storage Place & Illustrations
Storing Grain in Basket Granaries
Instruction Sheet for Storing Grain in Baskets
Storing Grain in Sacks
Mixing Grain and Insecticides for Sack and Small-Container Storage
Treating Stacks of Bagged Grain -- Recommended Insecticides and Dosages
Storing Grain in Sacks:  Summary
Airtight Storage
Storing in Gourds and Baskets
Storing Grain in Underground Pits
Storing Grain in Plastic Sacks, and Illustrations
Storing Grain in Metal Drums
Storing Grain in Metal Bins
Sheet Metal Silo
Fumigation of Small Quantities of Stored Grain:   in Plastic Bags
under Plastic Sheets
and in Small Metal Containers or Silos
Storing in Earthen Structures
The Indian Pusa Bin
Improved Mudblock Silo
How to Use Your Mudblock Silo
Ferrocement for Grain Storage
An Overview of Grain Storage Uses for Ferrocement:
Thai Ferrocement Silo (Thailo)
Ferrocement-lined Underground Pits
and Other Ferrocement Grain Structures
Storing Grain in Cement/Concrete Structures
Brick Grain Storage Silo
The 4.5 Ton Cement Stave Silo
Instructions for Use of the Cement Stave Silo
Concrete Block Square Silos for Cooperative Storage
                         PURPOSE OF THE MANUAL
Small Farm Grain Storage is a set of how-to manuals.   Together these
volumes provide a comprehensive overview of storage problems and
considerations as they relate to the small farmer.   The authors
recommend the volumes be purchased as a set because the material forms
an excellent and complete working and teaching tool for development
workers in the field.  This grain storage information can be adapted
easily to meet on-the-job needs; it has already been used as the
basis for a grain storage workshop and seminar in East Africa.
This set of publications retains the purpose of the original volume:
to bring together and to communicate effectively to field personnel
1) the basic principles of grain storage and 2) the practical solutions
currently being used and tested around the world to combat
grain storage problems.  Only the format has been changed to:
 *   reduce printing and postage costs.
 *   permit updating and revising one volume at a time.
 *   provide smaller books that are easier to hold and use
    than the large, single volume.
 *   make portions of the information available to the user
    who is especially interested in only one or another of
    the major aspects of small farm grain storage.
Of course, it is impossible to cover all storage situations in this
manual.  But farmers who understand the basic, unchanging principles
of drying and storing grain are better able to adapt ideas, suggestions,
and technologies from other parts of the world to their own needs.
This material was prepared for use by those who work to facilitate
such understanding.
Volume I, "Preparing Grain for Storage," discusses grain storage
problems as they are faced by small-scale farmers.   This volume
contains explanations of the structure of grain, the relationship
between grain and moisture, the need for proper drying.   One large
section contains detailed, fully illustrated plans for constructing
a variety of small-scale grain dryers.
Volume II, "Enemies of Stored Grain," is an in-depth study of two
major enemies:  insects and rodents.  Each is discussed in detail
with guidelines for 1) defining the size of the problem and 2) protecting
grain by both chemical and non-chemical means.   This volume
includes dose and use information for a variety of pesticides, as well
as suggestions for preparing materials to be used in audio-visual
Volume III, "Storage Methods," contains a survey of storage facilities
from the most traditional basket-type granary to metal bins and cement
silos.  The emphasis in this volume is on improving existing facilities;
for example, there are detailed construction procedures for an
improved mud silo.  Storage in underground pits and sacks also is
discussed.  There are guidelines for using insecticides in storage
situations.  The largest silo presented in detail is the 4.5 ton
cement stave silo.
Carl Lindblad served as a Peace Corps Volunteer in Dahomey (Benin)
from 1972 to 1975.  As a Volunteer, Lindblad worked in programs
designed to introduce and popularize a variety of grain storage
technologies.  Upon his return to the United States, he began the task
of pulling together this manual as a consultant to VITA and Peace
Corps.  At present, he serves as a consultant to a number of international
organizations, specializing in appropriate technologies for
grain storage -- in the areas of planning, extension and evaluation.
He spends much of his time in the field.
Laurel Druben served as an International Voluntary Services, Inc.
Volunteer in Laos from 1966 to 1968.   While in Laos she was a
curriculum planner and a teacher of English as a second language.
Subsequently, she worked with a consulting firm evaluating government-funded
research and development projects, ran a small education-oriented
business, and was a free-lance consultant and proposal
writer.  Druben, who has worked and lived in India and Micronesia,
as well as Southeast Asia, is Director of Communications for VITA.
Many thanks are due to the skilled and concerned people who worked to
make this manual possible:
    A number of VITA people provided technical review, artwork,
    and production skills:
    Staff assistance -- John Goodell
    Section 4, Vol. I materials -- Frederick Bueche
    Technical review -- Douglas Barnes, Merle Esmay, Henry Highland,
                        Larry Van Fossen, Harold Willson, Kenton Harris
    Artwork -- George Clark, John Goodell, Kenneth Lloyd,
               Nicholas Reinhardt, Guy Welch
    Thanks are extended to the following individuals and institutions
    that provided invaluable assistance in early stages of work on
    the manual:
    Mary Ernsberger and Margot Aronson, Peace Corps Program and
        Training Journal, USA
    Brenda Gates, Peace Corps Information Collection & Exchange, USA
    Tropical Stored Products Center, TPI, Great Britain
    Henry Barre and Floyd Herum, Agricultural Engineering Department,
        Ohio State University, USA
    Department of Grain Science and Industry, Kansas State University,
    Agricultural Research Service, Department of Agriculture, USA
    Extension Project Implementation Department, Ministry of
        Agriculture, Ethiopia
    F. W. Bennett, Midwest Research Institute, USA
    Supervised Agricultural Credit Programs (SACP), Belize
    Peter Giles, Nicaragua
    Donald Pfalser, Agricultural Cooperatives Development International
        (ACDI), USA
    Technical Assistance Bureau, US Agency for International
        Development (AID), USA
    International Development Research Center, University of Alberta,
    League for International Food Education (LIFE), USA
    Institut de Recherches Agronomiques Tropicales et des Cultures
        Vivrieres (IRAT), France
    Post-Harvest Crop Protection Project, University of Hawaii, USA
    Agricultural Engineering Service, FAO
    African Rural Storage Center, IITA, Nigeria
    Institute for Agricultural Research, Ahmadu Bello University,   
    Swaziland Rural Grain Storage Project
    Jim McDowell, Food Technology and Nutrition Section, UNICEF, Kenya
    Gordon Yadcuik, Centre Nationale de Recherches Agronomiques (CNRA),
    R. A. Boxall, Indian Grain Storage Institute, A.P., India
    Siribonse Boon-Long, Ministry of Agriculture and Cooperation,
    Asian Institute of Technology, Chulalongkorn University, Thailand
    Merrick Lockwood, Bangladesh Agricultural Research Council
    International Rice Research Institute (IRRI), Philippines
    Dante de Padua, University of Los Banos, Philippines
Small Farm Grain Storage is part of a series of publications combining
Peace Corps practical field experience with VITA technical expertise
in areas in which development workers have special difficulties
finding useful resource materials.
ACTION/Peace Corps
Since 1961 Peace Corps Volunteers have worked at the grassroots level
in countries around the world in program areas such as agriculture,
public health, and education.   Before beginning their two-year
assignments, Volunteers are given training in cross-cultural, technical,
and language skills.  This training helps them to live and work
closely with the people of their host countries.    It helps them, too,
to approach development problems with new ideas that make use of
locally available resources and are appropriate to the local cultures.
Recently Peace Corps established an Information Collection and
Exchange, so that these ideas developed during service in the field
could be made available to the wide range of development workers who
might find them useful.  Materials from the field are now being
collected, reviewed, and classified in the Information Collection and
Exchange system.  The most useful materials will be shared with the
development world.  The Information Collection and Exchange provides
an important source of field-based research materials for the production
of how-to manuals such as Small Farm Grain Storage.
VITA people are specialists who volunteer their free time to answer
requests for technical assistance. Many VITA Volunteers have lived
and worked in other countries, often as Peace Corps Volunteers.  Most
VITA people now work in the United States and other developed
countries where they are engineers, doctors, scientists, farmers,
architects, writers, artists, and so on.   But they continue to work
with people in other countries through VITA.   VITA Volunteers have
been providing technical assistance to the Third World for almost
20 years.
Requests for assistance come to VITA from many nations.   Each request
is handled by a Volunteer with the right skills.   For example, a
question about grain storage in Latin America might be handled by a
professor of agriculture, and a request for an improved planting
implement would go to an agricultural engineer. These VITA Volunteers,
many of whom have lived and worked in Third World countries, are
familiar with the special problems of these areas and are able to give
useful, and appropriate, answers.
VITA makes the expertise of VITA people available to a wide audience
through its publications program.
                       HOW TO USE THIS MANUAL
Development workers can use material from this manual in a number of
     * Discussions.  The manual provides clear presentations of grain
       storage principles from which you can take material to lead
       discussions with farmers and village leaders.
     * Demonstrations.  There are suggestions for demonstrations and
       experiments which you might find helpful to illustrate grain
       storage principles to farmers.
     * Leaflets.   Some of the material has been prepared in the form
       of illustrated leaflets which can be used directly by you
       with a farmer.   They may require little or no adaptation by
       you.   But, if you prefer, you can use the structure of the
       leaflet and substitute photographs specific to your area.
       The material on rodent control in Volume II is a good example
       of this kind of leaflet.
     * Construction Plans.  Many of the construction plans have been
       simplified so that you will be able to work more closely with
       the farmer.  Some of the plans are fully illustrated.  You
       could add photographs of the work steps showing conditions in
       your area.  It is likely that after you introduce the material,
       farmers can follow the instructions themselves.  The
       plans are written so that they would be easy to translate
       into local languages.  The Improved Maize Drying Crib in
       Volume I is a good example of a step-by-step, illustrated
     * Checklists.  Some of the material most likely to be useful for
       small-scale farmers has been simplified and prepared in checklist
       or hand-out form.  This material would lend itself to
       illustrations or photographs, so it can better fit into the
       local situation.  The checklists on controlling grain storage
       insect pests included in Volume II are in this category.
     * Examples.   The appendices contain examples of leaflets that
       have been prepared by development workers in several countries.
       These examples have been included to give you some
       idea of how the materials in this manual might be organized,
       illustrated, translated, and presented to reach farmers.
     * Sources.   Wherever Possible, addresses are given so that you
       can write for more information on a subject.
     * Further Information.  Other appendices contain information on
       areas which, although important, cannot be covered fully within
       the scope of this manual, for example, storage program
       planning.   A bibliography is provided at the end of each volume.
These are some of the aims of Small Farm Grain Storage.   You will
probably find added uses.  While it is not possible to make this
manual specific to the situations or culture of your particular area,
the information is presented so that you can do this very easily by
making additions or substitutions to the material.
Dimensions are given in metric units in the text and illustrations.
Conversion tables are provided at the end of each volume.
This manual will grow and change as its readers and users send in
additional material, comments, and ideas for new approaches to grain
storage problems and better ways to communicate with farmers.  Your
own ideas and conclusions are welcome.   A form has been included for
your comments.  Please send us the results of your silo or dryer
building.  Let us know how you used the information and how it could
be make even more useful to you.   Tell us how you changed a plan to
fit local needs.
Your experience will help us to produce manuals of growing usefulness
to the world-wide development community.
For your convenience, a reply form has been inserted here.  Please
send it in and let us know how the manual has helped or can be made
more helpful.  If the reply form is missing from your book, just put
your comments, suggestions, descriptions of problems, etc., on a
piece of paper and send them to:
                         GRAIN STORAGE
                         3706 RHODE ISLAND AVENUE
                         MT. RAINIER, MD 20822

51cp01.gif (437x437)

Each farmer has some method of storing his grain.   Any improvement in
this storage method must be made by steps the farmer sees as the right
ones for his situation or need.   A farmer who stores his grain in sacks in
a corner of his house may not be ready to build a cement silo.  Because
this farmer is afraid that thieves will take his grain, he may not want
to build any type of storage container outside his house.
For this farmer, trying a different drying method, or cleaning his storage
bags, or improving a stacking arrangement, or adding insecticides to sacked
grain could be a large, first step toward improved storage.
If a farmer is complaining about insects and rodents eating his stored
grain, you have an opening to say, "Let's do something about that problem."
But if the farmers in your area feel, "It's always been that way, and there
is nothing we can do about it," your first job is to convince the farmer
that there is something he can do about his problems.
Only you can introduce the material from this manual because you know the
area where you work.  Hopefully, the earlier parts of this manual have
provided a lot of helpful information and material.   If a farmer is not
ready to make improvements in his storage method, perhaps you can find the
material in this manual to put together leaflets which would help show
what change could do for him.   One convinced farmer may be all it takes
to get things started.
Change only begins when farmers believe that new ideas and technologies can
be helpful to them.  They may start out by making only small changes in
the method already being used.   But the important point is that something
different is being tried.  Then, when the farmer sees an improvement in
the quality of his stored grain, you have an opening to say, "Now perhaps
you would like to try a storage method that can do even more for you."
Perhaps that is the time to suggest a metal drum or a mud silo.
You know from your work that change seems to be accepted very slowly.  It
is good to keep in mind the fact that for a farmer who has always done
things the same way, adding a small amount of insecticide to a sack of
grain is a large change.  It is very easy to give people more than they
want or are ready to receive.
This section of the manual brings together all the grain storage information
which was introduced earlier:
       * It discusses and shows some traditional storage methods
         and gives specific directions for improving these methods.
         Some of these methods are sack, basket, and pit storage.
       * It gives plans for, among others, mudblock, ferrocement,
         oil-drum and cement-stave silos.
       * It describes other storage possibilities to give some
         idea of the range of methods in use.
This section, together with the earlier parts of the manual, ought to help
you to help farmers define their choices.   To provide even more information,
there are some valuable appendices to the manual:
                         STORAGE PRINCIPLES
Whichever kind of storage method a farmer uses, there are certain principles
upon which every method is based.   Every storage container, no matter what
it looks like or what it is made of, should:
       * keep grain cool and dry.
       * protect grain from insects.
       * protect grain from rodents.
All storage methods try to do the above three things.   But to do these
things requires the following good storage practices:
       1.   Drying grain well (to 12-13% moisture content) before
           putting it into storage.
       2.   Putting clean grain only into containers which have had
           all old grain, dust, straw, and insects removed.
       3.   Keeping the grain cool and protected from large changes
           in outside temperatures.  This can be done in a number
           of ways -- by using building materials which do not easily
           pass on changes in outside temperatures to the stored grain,
           by keeping or building storage containers away from direct
           sunlight, by painting the containers white.
       4.   Protecting the grain from insects by following rules for
           cleanliness and drying, by applying insecticide and/or by
           putting the grain into airtight storage.
       5.  Waterproofing the buildings and containers as much as possible.
           This is done both by the way the building is constructed
           and by applying materials which keep water from soaking into
           the building material.  Storage buildings should be built on
           well-drained locations.  They should not be placed where they
           will be flooded by ground water run-off during heavy rains.
       6.   Making sure containers are rodent-proofed in all possible ways.
       7.   Checking the grain regularly while it is in storage to
           make sure it is not infested, and following recleaning
           instructions to destroy insects, if they are found when
           the grain is checked.
A farmer who has these seven points firmly in mind will know why a
particular silo or storage method has been built or changed in a certain
way.  And he can then do much to improve his own storage facility by
applying the knowledge to his own problems.
The ideas and suggestions for storage methods which follow in this section,
no matter how different they look, all require that these seven steps
be taken if they are to be successful.
                     FINDING A GOOD STORAGE PLACE
                             SCRIPT # 1
Suggested Use:  This script and the one which follows contain some
                of the important points to remember about finding,
                cleaning, and repairing storage places.  VITA Volunteer
                artist Guy T. Welch has provided illustrations
                of some of these points to give some ideas on ways
                this material can be presented through pictures.
     * Rats, mice, birds, insects,and mold destroy a lot of
       grain.   It is not easy to keep these dangers away from
       your grain.  But you can do a lot to keep them away.
     * Fix a good place to put your grain before you bring
       it from the field.
     * The place for grain storage is very important.  Grain
       storage places must be built on well-drained ground,
       so the building or container does not get flooded
       or take on too much moisture from the ground.
     * Most insects and molds like warm, wet places.
     * A good storage place is cool and dry.
     * Grain storage is easier if you live in a cool, dry
       land.   Grains are easier to protect.
     * But insects and rodents can attack even in these
       places.   Farmers must protect the grain from these
       pests wherever they live.
     * Some farmers store grain in large clay jars with
       thick walls.
     * Some farmers use metal drums for grain storage.
     * Some farmers in warm places put grain in buildings
       with thick mud, plaster, cement, or thatched walls
       and roofs.  Thick walls help to keep the hot air out.
       Thick walls help to keep the grain cool.
     * Some farmers store grain under the ground.  Grain
       stored under the ground is kept cool by the earth.
     * You can put grain storage containers or jars on rocks
       or wood.   This keeps the containers off the ground.
       Air can get under the container.  This air cools the
     * You can build storage rooms or buildings on posts.
       This keeps the floor off the ground.  Water from the
       earth can not get the floor wet.  Air can pass under
       the storage building to cool the grain.
     * There are many ways to store grain.
     * Remember that the storage place must keep grain cool
       and dry.
     * Remember that the storage place must be clean and free
       of insects and rodents.
     * Your extension worker can help you find a way to store
       grain that is good for you.

51cp05.gif (437x437)

51cp06.gif (486x486)

51cp07.gif (600x600)

51cp08.gif (486x486)

51cp09.gif (486x486)

  <FIGURE 6>
                    SCRIPT # 2
*  Your storage room or building must be clean.  Insects
   live and have families in dirty places.  Rats, mice,
   and other pests like dirty places too.
*  Take away and burn or compost all dust, old pieces of
   grain, dirt, straw, and chaff from the storage place.
*  There should be no cracks and holes in the floor,
   ceiling,or walls.  Insects and rodents use these holes
   to get in.
*  Fill and seal all cracks and holes.
*  Seal large holes in wooden storage places with sheet
   metal, flattened tin cans, or pieces of wood.
   Concrete and plaster make good sealing material for
   plaster, brick,and concrete buildings.
*  Put paint or whitewash on the walls and floors of the
    storage area.   This paint helps close up very small
   holes.   Insects like these small holes.
*  Do not use any poison until you talk to your extension
*  Put mesh wire over large openings and windows.  This
   will keep out rats, chickens, and birds.
*  The roof must keep rain from coming in.  The grain
   must be kept dry.
*  Mend all holes and openings in the roof.
*  Clean the outside area around the storage place.
*  Clean out the containers that you put the grain in.
*  Bags or sacks for storing grain must be shaken.
*  Bags or sacks should be boiled in hot water and dried
   in the sun.   Mend any holes you find in the bags.
*  Check with an extension worker for information on
   poisons to kill insects and rodents.
*  The extension worker will know what poison to use.  He
   will know how to use the poison.
*  Always remember that many poisons can kill animals and
*  Use insecticide on the inside and outside of your
   storage area.
*  Put insecticide on all cracks and small places where
   insects like to live.
*  Put out traps for rodents.
*  A good storage place is free of insects and rodents.
   It is clean and dry.

51cp12.gif (486x486)

51cp13.gif (486x486)

51cp14.gif (486x486)

51cp15.gif (486x486)

51cp16.gif (486x486)

Grain has been stored in basket-like containers made of grass, reeds,
bamboo strips, or small branches for thousands of years.  The particular
building material depends upon the plants available near a farmer.
These basket granaries are so traditional and widely used that it does
not seem necessary to include a plan for making them.   There are almost
as many different kinds of baskets as there are villages making them,
and the skills for this kind of work are passed on within families.
What this manual will present is some suggestions for improving basket
granaries so that grain stored in them is more protected from insects
and molds.
To increase the protection of grain kept in baskets:
   *   Keep the basket off the ground.   Make a strong platform
      upon which the basket can sit.  The shape of the platform
      will depend upon the shape of the basket.  Putting
      the basket on a platform prevents moisture from coming
      through the ground into the basket.  The platform also
      offers more protection from rodents.

51cp17.gif (486x486)

   *   Make sure the basket is well-protected from the rain.
      If it is a grass or reed basket, keep it in the house
      or some other dry building.  If it is woven of material
      which can be kept outside, make sure the roof thatch
      does not let any rain into the grain.
   *   Place rodent baffles (guards) on the legs of platforms
      which support the baskets.  These prevent rodents
      from climbing or jumping into the baskets.  (The rodent
      proofing section contains information on making rat
   *   A tin can, with a plastic-cover that can be put on and
      taken off easily, makes a good emptying chute (see
      the picture below).  Cut the bottom out of the can and
      fit the open end of the can into the lower part of
      the basket.  This makes it unnecessary to take off
      the cover each time grain is taken out.
   *   Baskets can be plastered inside and outside with
      mud, clay, or cow dung.   Covers should be tight and
      sealed with plaster of the same material.  It is
      important for farmers to realize that grain holding
      a lot of moisture, whether threshed or freshly
      harvested, should not be placed in baskets which
      have been plastered in this way.  Plastering makes
      the basket much more airtight.  Moist grain needs to
      have air passing through to dry it.  If moist grain
      is put into storage without enough air, it will mold
      and rot quickly.

51cp18.gif (540x540)

This instruction sheet includes some directions for using insecticide
in basket storage.  You should include the names of insecticides available
in your area which are appropriate for use with grain being stored
in baskets.  (Malathion and Pyrethrum are mentioned.)
You may want to use the information to make two instruction sheets:
one explaining good basket storage without insecticide; the other,
with use of insecticide.  Also, you may want to illustrate the sheets
if you hand them out to farmers in your area who use basket granaries.

51cp19.gif (486x486)

     *   Make sure the area around the basket is clean.  Baskets
        should always be kept inside a building unless the
        baskets have been built for outside use.
     *   Place the basket on a platform so that it will not
        pick up moisture from the ground.
     *   Clean out all grain dust and broken grains if the
        basket has been used before.
     *   Mend any holes in the basket.
     *   Plaster basket with mud, clay, or cow dung if storing
        very dry grain.
     *   Dust the inside of the basket with insecticide.  Do
        this carefully so any insects will be killed.
     *   Mix the dry grain with insecticide before you put it
        into the basket.  To mix the grain and insecticide,
        you must:
        Place the dry grain on a plastic sheet, clean floor,
        or hard-packed ground.
        Sprinkle insecticide over the grain.  Use 1 packet
        (4 oz.) of Malathion or pyrethrum dust for each 100
        kg of grain.
        Mix the grain and insecticide with a shovel until
        they are mixed very well.
     *   Mix burned cow dung or wood ashes with the grain.
     *   Winnow, sieve, or place the grain in the sun.
     *   Clean the basket.
     *   Add more insecticide or ashes.
     *   Put the grain back and replace the cover tightly.
                     STORING GRAIN IN SACKS
Putting grain in sacks (bags) is a very old
method of storing.  Storage sacks are made
of woven jute, hemp, sisal, local grasses,
cotton -- whatever material is available
in the area.  Sacks are relatively expensive
as they do not often last for more
than two seasons.  Sacks do not give a lot
of natural protection against insects,
rodents, and moisture.  But sack storage
has some advantages for the small farmer,
and there are things farmers can do to
protect their sacked grain.

51cp21a.gif (317x317)

The Advantages of Sack Storage for Farmers:
     *   Grain stored in sacks made of fibers can have a little
        higher moisture content than grain put into airtight
        storage.   If the sacks are properly stacked, air can
        move through the sacks to dry and cool the grain.

51cp21b.gif (437x437)

     *   Sacks are easy to label.   Farmers can label old
        grain sacks and new grain sacks to keep them
        separate.  Seed grain can be marked and kept
        separately from the other grains.
     *   Sacks are easy to move around.   And sacks or
        parts of sacks can be used as they are needed.
     *  Sacks can be stored in a farmer's house - no special
        buildings or containers are needed.
     *   Farmers in a village may decide to build a shed
        to hold the grain belonging to all the village's
        farmers.   It is easy to mark sacks so that each
        farmer's grain can be found simply.
Grain stored in fiber sacks is easily attacked by insects, rodents,
and molds.  Often these attacks are worse because a farmer has no
all he can to protect his grain sacks.
     *   Dry the grain well.   Although grain can contain
        about two percent (2%) more moisture for sack
        storage than for airtight storage, the grain should
        be as dry as possible.
        Check the grain every two weeks.  Suggest to the
        farmer that he make checking his grain part of a
        weekly or bi-weekly routine.  Put his hand into
        a sack of grain to check for heating.  He can
        smell the grain and look for dark kernels:  signs
        of mold.   If these signs are found, he should
        dump out the grain and dry it again.
     *   Waterproof the walls and roof of the building where
        the grain is stored.
        This keeps sacked grain from taking moisture from
        the floor.  Farmers can make these platforms out
        of whatever materials they have.  If no wood or
        bricks are available to make a platform, the
        ground can be covered with plastic sheets.  The
        raised platform is better than the plastic because
        it also allows air to flow under the sacked grain.

51cp22.gif (486x486)

     *   Stack the sacks in a neat manner. Leave space between
        the sacks so that air can move freely between the

51cp23a.gif (486x486)

     *   Mend cracks in the walls, roof,
        and doors of the building where
        grain is kept.  This mending
        keeps insects from getting in
        and out of the building through
        the cracks.

51cp23b.gif (353x353)

     *   Remove and check sacks of grain
        left from the last harvest.  The
        farmer should take them outside
        before he cleans the storeroom.
        This grain should be winnowed,
        sieved, and spread out in the
        sun for a time before it is put
        back into the bags.  If the rain
        is seived, light a fire and burn all the insects found, so they
        will not move right back into the grain.
     *   Clean the room well before placing
        the sacks inside.  Make sure there
        is no dust, dirt, and old grain left.
        Sweep walls and ceilings as well as
        the floors.  Some farmers may want
        to burn a small, smoky fire in the
        room to drive out insects, if they
        are not going to use insecticide to
        protect the inside of the building.

51cp23c.gif (317x317)

If Insecticide Is Available
     *   Apply insecticide to the storage building.  You can recommend
        DDT, Malathion, and Lindane for use on buildings and
        instruct the farmer on use of these three poisons.  There
        also are other insecticides that can be used on buildings.
     *   Dust insecticide on the sacks before the grain is put in.
        (Or the insecticide can be put on the bags as they are
        stacked.   There is a page attached to the end of this section
        which gives instructions on applying insecticides
        as you stack grain.)  Malathion is a safe insecticide
        for a farmer to use for this purpose -- it is safe
        for him to use and safe for his grain.  Brush the sacks
        with a stiff brush and then shake them well.  Brush
        both the outside and the inside of the sack.  Put
        Malathion on both the inside and the outside of the
     *   Mix the grain with insecticide before it is placed in
        bags.   Use only clean, dry grain. See the end of this
        section for instructions on mixing grain and insecticide
        for sack storage.
If Insecticide Is Not Used
     *   Clean the sacks carefully.   Shake the sacks well.   If
        sacks are made of a material which can be placed in
        hot water, boil the sacks or dip them in very hot
        water.   Dry the sacks in the hot sun.   If sacks can
        not be placed in water, brush them well and place them
        in the sun.  Make sure both the inside and the outside
        get exposed to the sun.

51cp24.gif (382x528)

     *   Use only clean, dry grain.   The grain should be checked.
        It should be free of insects (the easily seen adults,
        at least).
     *   Mix ash from cattle dung or wood or fine sand with the
        grain if insecticide is not to be used.  Use one, 10-liter
        bucket of ash for each 100kg of grain.
     *   Stack the sacks carefully (as shown earlier).  The platform
        holding the sacks must be placed away from the walls
        because there are insects which live in wood and thatch
        which will move to the stored grain.

51cp25a.gif (437x437)

     *   Check the grain regularly.   If no insecticide has been used,
        a farmer may have to dump the grain out, get the insects out,
        and re-bag the grain every two months or so.  If Malathion is
        used, that insecticide possibly will have to be reapplied after
        four months of storage.
     *   Keep the area around the sacks clear of dirt,
        broken grains, grain dust, and trash.  This clearing
        makes it harder for rats and mice to find home and
        food near the stored grain.

51cp25b.gif (486x486)

        -- Cover and repair holes that rodents might use to get
           into the building where the grain is stored.
        -- Keep the sacks off the floor.  This does not stop
           rats and mice from attacking the grain.  but it does
           make cleaning, poisoning and baiting, and looking
           for rats and mice easier.
        -- Move the stacks if rodents are seen.  Then use traps
           and poisoned baits near the pathways and rodent holes.
           (See the section on rodent control for more information
           on using traps and poisons to control rodents).

51cp26.gif (393x393)

     *   Sacks and buildings which are clean.
     *   Dry grain which is free of insects.
     *   Good shelter which keeps out rain, insects, rodents,
        and birds.
     *   Careful checking of the grain while it is in storage.
The following pages include:
     *   Instructions which can be given to farmers to aid them with
        mixing grain and insecticides for sack and small-container
     *   Instructions for adding insecticide while stacking layers
        of grain bags.
     *   Sample material for a leaflet which could be made to
        illustrate proper sack storage through pictures.
The following insecticides and dosages are recommended for direct mixing
with grain:
     -- Malathion.  Use 120 grams of 1.0% dust for each 200kg
                    of grain.
     -- Lindane.   Use 120 grams of 0.1% dust for each 200kg of
     -- pyrethrum.  Use 120 grams of 0.2% pyrethrins plus 1.0%
                    piperonyl butoxide dust for each 200kg of
If you can find Malathion, for example, only in 2%, 5%, or .5% mixtures,
you will have to adjust the strength of the insecticide.  For example,
if you are using 2.0% Dust,you need to use only 60 grams of 2.0% Dust
per 200kg.
     *   Apply the insecticide to one half sack of grain at a
     *   Empty one half of the grain from a sack onto hard-packed
        earth, a plastic sheet, or clean floor.
     *   Put 60 grams of insecticide dust on the grain.
     *   Turn the grain over and over with a shovel.  Make sure
        the grain and insecticide are well-mixed.
     *   Empty the other half of the sack on top of the grain you
        have just mixed.
     *   Put the rest (the other half -- 60 grams) of the insecticide
        on the grain.
     *   Mix very well.
     *   Put the grain back into the sack and close it tightly.
There are two ways to apply insecticide to stacks of sacked grain:
   1.   Layer by Layer
       Spray or dust each layer of sacks with Malathion or Lindane
       as the stack is being built.
       Malathion -- 25 grams of 2.0% Dust per sack
                    50 grams of 2.0% Dust per square meter
       Lindane    -- 25 grams of 0.5% Dust per sack
                    50 grams of 0.5% Dust per square meter
   2.   Stack Treatment
       Build the stack first.  Then spray all four sides and the top
       surface of the stack.  Use Dispersible Powder formulations of
       Malathion and Lindane at the dosages recommended for spraying
       storage buildings.
When this treatment is finished, apply a band of insecticide around the
bottoms of the stacks to control crawling insects.   Malathion is best
for this job, though where it is not available, Lindane or DDT may be used.
                      STORING GRAIN IN SACKS
Suggested Uses:  This is an easy-to-read summary of the important
                 things to remember for good sack storage.   Pick out
                 the points that best fit your situation and use them
                 with farmers in your area.  They are simply worded
                 and can easily be pictured by using drawings or photographs;
                 they can be translated easily.
     *   Grain is often stored in sacks.   Sacks are also called bags.
     *   Sacks are made of different things.
     *   Sacks are easy to put away.   You can store them in a corner
        of the house.
     *   You can put grain sacks in a special storage building.
     *   Sacks are easy to carry.
     *   Each sack can be labeled to show what is inside.
     *   Put your name on each sack.   It is easy to show which grain
        belongs to you.
     *   Insects, rats, and molds can attack grain kept in sacks.
     *   You can protect the sacks from these dangers.  You must start
        before the grain goes into the sack.
     *   Clean your storage area well.
     *   Make sure there is no dust, old grain, straw, or trash in
        the storage place.
     *   Mend holes in the roof, floor, or walls.
     *   Check for cracks.   Insects hide there.
     *  Make sure rain and water from the ground can not get the
        grain wet.
     *   Put rat guards on the legs of storage containers or buildings.
     *   Ask your extension agent about insecticides you can use.
     *   Shake out old storage sacks.
     *   Put old sacks in boiling water, if possible.
     *   Dry old sacks in bright sunlight.
     *   Mend holes in the sacks.
     *   Spray or dust the sacks with insecticide.
     *   Spray or dust the building with insecticide.
     *   Make sure the grain you put into the sack has no
        insects in it.
     *   Put only clean, dry grain into sacks.
     *   Some insect poisons can be put into the sack with the
        grain.   This protects the grain from insects for some
        time.   Ask your extension agent before you do this.
        Some poisons can poison the grain.
     *   You can add sand and ash to the grain in the sack.
        Insects do not like these materials.
     *   Poison is better than sand and ash.   But sand and
        ash are better than putting the grain in with no
     *   Close all sacks tightly.
     *   Put each kind of grain in a separate sack.
     *   Place grain sacks off the ground.
     *   If you have many sacks, stack the sacks well. Leave
        room between the sacks.  Air in the room will cool
        the grain better if there is room between the sacks.
     *   Do not stack sacks against the walls.   Insects and
        termites get into the grain from the walls.
     *   Check the sacks often. Look for insects.  Smell for
        mold.   Look for wet places.
     *   If you find insects or mold, dump the grain out of
        the sack and leave it in the sun.  Sieve the grain.
     *   Clean the sacks again.
     *   Put the grain back into the sacks immediately after
                                AIRTIGHT STORAGE
Insects can still grow and reproduce in very dry grain.   Grain dried to
a 12 or 13% moisture level will not mold, but can still be very good food
for insects.
The moisture level in grain has to be 9% or less to slow down insect
development.  Very high and very low temperatures also slow down insect
growth.  But most farmers will have trouble getting their grain below
12% moisture and in using temperature to control insect development.
They often do not have the special equipment necessary to do these things.
More and more farmers do use insecticides to control insects in grain.
But some insecticides are dangerous; some are expensive; sometimes they
are not available; and there is increasing concern about using chemicals
of any kind on food products.
Airtight storage simply means putting grain into containers which keep
air from getting into the grain.   Some air is let into the container at
the time the grain is put into storage.   But after the container is sealed,
no more air enters.  The respiration of the grain and any insects in it
uses up all the oxygen.  Insects need oxygen to live.  They die without
it.  Any molds present which require oxygen also will die.
       You can show farmers how airtight storage works by putting
       some insects and grains on a very smooth surface and
       turning a glass over on top of them.  Make sure the glass
       is tight against the surface.  Seal it with wax or some
       other material.  Or seal some grain kernels and insects in
       a glass jar.  Cover the jar with a screw-on lid or a
       plastic sheet.  Just make sure no air can enter the container!
       Wait for a while.  The insects will begin to move more
       slowly.   Finally, they will die.   How long it takes for
       the insects to die will depend upon the number of insects,
       the amount of grain, and the size of the glass container.
       You can speed up the experiment by placing a lighted
       candle under the glass container.  The flame on the
       candle requires oxygen to keep burning.  The flame
       will use up the oxygen in the container quickly.
       When the oxygen is gone, the flame will go out.  Soon,
       the insects will die.
The lack of oxygen, which kills insects, does not seem to hurt the
grain or to keep seed grain from germinating when it is planted.
Successful airtight storage depends upon a number of things:
       *   Building containers which are airtight.   This
          means using materials which do not let air flow
          through them, for example, metal, plastic, concrete.
          These containers must be checked to make
          sure there are no cracks or holes.  Sometimes a
          farmer will see light coming through cracks in a
          large container.  If the container is a gourd,
          for example, he can check for cracks by filling it
          with water to see if there are any leaks.  All
          cracks in storage containers should be sealed
          for good protection.  In addition, it is usually
          a good idea to coat or paint the entire outside
          (and sometimes the inside) surface of the container
          with tar or oil-based paints (they are
          waterproof and also do not let air pass through).
          For a farmer who cannot afford to buy these materials,
          there may be local trees and plants
          which produce materials useful for waterproofing.
       *   Sealing tightly the holes for putting grain into
          the container and for taking grain out.  Tar, wax,
          or pieces of rubber cut from old tires, and inner
          tubes can be used for this.
       *   Filling airtight storage containers to the top
          is important.  Full containers, which are sealed
          against air, can kill insects in a few days.  But
          if the container is not full, the insects take a
          lot longer to die.  And before they die, they may
          damage a lot of grain.
       *   Keeping the storage container closed.   Unless the
          airtight container is quite small, farmers probably
          will want to store the grain they use for food
          separately.  The storage container holding the food
          grain is opened often. Every time a container is
          opened, more air containing oxygen enters the
          stored grain.  This added air and frequent opening
          encourages insect growth.
Some of the storage methods used for thousands of years have been based
loosely on the principles of airtight storage.   A farmer might not call
his method airtight storage, or be able to tell you why it works.  He
stores his grain this way because it keeps his grain pretty safe, and he
has been doing it this way for many years.   Many of these methods are
basically good.  Improvements can make them more airtight and, therefore,
increase their ability to protect grain.
A farmer has to decide what he needs his storage method to do, and, then,
he must figure the costs of each method.   Some of the methods, such as
metal drums and plastic sacks, cost more money.   But they are definitely
airtight when used correctly and are very likely to make up their costs
by good storage of grain.  Other methods, such as the Improved Mudblock
Silo, are harder to make airtight, take longer to build, and require more
upkeep.  But they can hold large amounts of grain, and they can be made
with local materials.
Airtight storage is something farmers who store dry grain should work
a high moisture content should be stored so that air can pass over the
The rest of the material included in this section describes storage
methods which are quite airtight and waterproof or can be made so by
making the various improvements described here.   This material should
serve as a useful guide to some of the storage possibilities that are
available to small-scale farmers.
                       STORING IN GOURDS AND BASKETS
Gourds are the hard, dried outside cases (skins) of certain fruits or vegetables
(they are members of the squash family).   They are found in many
places and are used for storing small amounts of grain.   Grain for planting
is often stored in gourds.
Scientists are working to discover ways of making gourds effective airtight
containers for grain that has no more than 12-13% moisture in it.  Here
are some of the findings:
      *   Linseed oil or varnish painted all
         over the outside of the gourd
         makes it almost airtight.
      *   The stopper or cover for the gourd
         has to be sealed well.
      *   Pitch and bitumen are easier for
         farmers to get and seem to make the
         gourds airtight.
      *   Any thick substance which will stick
         to the gourd will work very well.
         There are probably local materials
         which can be found and made to seal
         the gourd.  It is likely that some
         of the materials found for waterproofing
         soil would be useful
         to seal the gourds.  If the
         material stays sticky and does
         not dry, sprinkle sand or earth all
         over it.

51cp34.gif (317x317)

If gourd-shaped vessels made of clay or other local materials are available
in your area, perhaps these can be made airtight in the same way.
Baskets made of local materials also can be made more airtight.  Cover the
baskets inside and out with mud plaster.   Make sure the cover closes
tightly.  The outside of the basket can then be coated with a waterproofing
or sealing-material.
Possible advantages:                 Disadvantages:
*  Useful for storing seed grain         *   Gourds do not hold large amounts
   and smaller quantities for food.         of grain.
*  Easy to get to the grain and to
   check for insects.
*  Easy to label, so the farmer knows what
   kind of grain is in each container.
Farmers store grain in underground pits (holes) in many parts of the world.
Pits are used for storing threshed sorghum and maize.   They also are used
for wheat, peas, and beans.  In areas where pit storage is used, it has
served farmers well as a way of avoiding theft of the grain (because the
pits are hidden).  Also, because the pits are dug deep into the earth, they
keep the grain cool.  In addition, some pits are relatively airtight.
However, pit storage is generally not a storage method to encourage a
farmer to adopt.  If a farmer is looking for a storage method, he is more
likely to get airtight storage by using oil drums, plastic sacks, etc.

51cp35.gif (393x393)

There are many, many kinds of pits.   The pits themselves are not always
airtight or waterproof.  Therefore, some farmers line the pits with straw
to absorb moisture from the earth or from leaks in the covers.  The
straw gets damp and becomes moldy.   These molds use up any air in the
storage pit, so that any insects present in the grain die.  Often in
underground storage pits, the grain at the top and around the sides of
the pit is moldy.  The main part of the grain, however, stores well.
In some areas, farmers build wet pits.   During the rainy season,,the water
in the ground may rise right into the pit.   The grain in this case is full
of water.  But the grain respires more quickly when wet and uses up the
oxygen.  Insects and molds requiring oxygen die.  Often these wet pits
are built where cattle are kept because cow dung uses up oxygen as it
decomposes.  The grain kept in wet pits may ferment (sour) and thus is
not good for seed.  But often it seems to store better than grain kept
in drier pits.
The question to keep in mind here is whether or not an improvement in
the traditional pit is wise or necessary.   A farmer who does not open his
pit often may have very light losses from insects and molds.  In this
case, making improvements may not be necessary.
However, in areas where farmers have lost a lot of grain stored in pits
due to insects and molds, it may be a good idea to offer several suggestions
for improving the pit storage.   Pit storage can be made more safe by improving
the covers, building shelters over the pits,,or by using a lining
in the pits.
Replacing Covers
Pit storage usually can be improved by replacing wood and mud covers with
metal or plastic covers.
     *   Use one large sheet of metal or plastic to cover the entire
     *   Make a hole in the middle of the large sheet.  This is,so grain
        can be taken out.  Cover the smaller hole with a piece of
        of the same material.
     *   Seal the entire cover with a mixture of mud or dung or with
Building Shelters
Some farmers build shelters over the pit stores.   The shelters should be
movable so that when the sun is shining, the pit can be exposed for drying.
The shelter should be used when it rains.   The problem with this type of
shelter is that the farmer cannot keep the place of the pit a secret and
the grain may be taken by thieves.
Improving Pit Linings
The other area where pits can be improved is the lining used in the pit.
Straw and Mat Lining
     *   Put down a layer of straw on the pit floor.  Cover the
        straw with mats made from bamboo or local grasses.
     *   Line the walls with straw and matting as well.
     *   Pour in dry grain to the top of the lining.
     *   Continue placing the lining and pouring the grain until
        the pit is full.

51cp37a.gif (600x600)

      Advantages:  Uses local material and costs nothing.
                   Stores grain much better than an unlined pit.
      Disadvantages:  Does not protect the grain as well as the following
Plastic Bags
     *   Place very dry grain in
        plastic sacks.
     *   Seal tightly as shown.
     *   Store sacks in the pit.
     *   Seal the pit well.

51cp37b.gif (486x486)

     Airtight if the bags are well
     A farmer can remove part of the grain
     easily without letting air and
     moisture into the rest of the grain.
     May be expensive or hard-to-get.
Plastic Lining
     *   Line the pit with large plastic sheets or with plastic bags cut
        open to make sheets.
     *   Make sure the edges of the plastic sheet lie over each other.
     *   Fill the pit with clean, dry grain and seal tightly.
     Advantages:   Gives good protection from moisture if the
                  plastic is sealed.
     Disadvantages:  Can be damaged easily.
                     Plastic may be expensive, unavailable, and
                     hard to replace.
Using Plastic Lining and Plastic Bags in Large Pits
     *   Lay plastic sheets or cut-open plastic bags on the floor.
     *   Fill a number of plastic bags with very dry grain and put these
        against the sides of the pit.
     *   Pour dry grain into the space between the floor and the tops
        of the sacks.
     *   Put another layer of filled plastic sacks against the walls
        on top of the sacks already in the pit.
     *   Fill the space with grain.
     *   Continue placing plastic sacks against the sides and pouring
        in grain until the pit is full.
     *   Cover the top of the grain with plastic.
     *   Seal the pit

51cp38.gif (540x540)

Advantages:  Keeps most of the grain
             very well.
             Stores large amounts of
      May be hard to find
      May be expensive.
      Loses some grain because
      it falls down between the
      bags and the walls of the
Concrete Linings
There has been work done on various concrete linings for underground pits.
Because this method requires more labor, material and money, it is not
as easy for a small farmer to use.   However, it will be outlined in more
detail in the part of this manual which discusses ferrocement.
Plastic bags make good airtight storage containers.
     *   Use plastic bags which are .20 to .25mm thick (500-700 gauge).
     *   Make sure there are no holes in the plastic.  Even the
        smallest hole will cause problems.
     *   Some insects can puncture plastic when trying to escape from
        the sack. But this can be stopped by putting a cloth bag
        of tightly woven cotton inside the plastic bag.  The
        cloth is added protection.
     *   Use grain which is very dry.
     *   Add insecticide to the grain.   It can take a week or more
        for insects to use up the oxygen which is in the bag.
     *   Fill the sacks and seal them tightly.
     *   Store the filled bags off the ground on a smooth surface so
        that they will not be punctured by the floor or anything
     Advantages:       Plastic bags are easy to store.
                      Plastic bags are easy to move around.
                      They provide good protection against insects.
                      Plastic bags make good containers for fumigating
                      small quantities of grain.
     Disadvantages:   Plastic can be torn or punctured easily.
                      They are generally good for only one year
                      and must be replaced after that because
                      small holes have been made in them.
                      Rodents can eat through plastic.
                      Plastic bags are expensive in some area.
The following leaflet, prepared by VITA artist Ken Lloyd is designed to
show farmers a good procedure for storing dry grain in plastic sacks.

51cp40.gif (600x600)

51cp41.gif (600x600)

51cp42.gif (600x600)

                    STORING GRAIN IN METAL DRUMS
In many parts of the world, 220-litre oil drums
are available and not too expensive.   If farmers
in your area can find oil drums, this is a
storage method which may be a good improvement.
Sorghum, maize, millet, cowpeas, and groundnuts
are among the materials which can be stored
successfully in these drums.   The grain should
be dry (12% moisture or less) when it is put
into the drum.

51cp43.gif (317x317)

Here is the procedure for using a drum:
     *   Make sure the drum is clean and dry inside.
     *   Check for holes.   Holes in these drums can be plugged
        with wax.
     *   Pour clean, dry grain into the drum through the small
        top opening.  Use a wide-mouth funnel to help with
        this job.
     *   Shake the drum to let the grain settle; then fill it
     *   Make sure the drum is full.
     *   Screw the cap on tightly.   If the rubber ring on the
        inside of the cap is missing, smear the cap with grease.
Each drum holds about 660kg of grain.
     Advantages:   Provides good airtight storage control of insects.
                  Protects the grain from rodents.
                  Works well for seed grain; does not seem to hurt
                  the ability of the seed to germinate.
                  Is available in most areas and is not expensive.
                  Makes a good container to fumigate grain in.
     Disadvantages:  Has a small opening for filling and emptying.
                     Special clamp-on lid is sometimes available.
                     But this lid does not create airtight conditions
                     and insecticides must be used.
                     Works best when grain is being stored 5 months
                      or more.
                     Has to be kept out of sunlight to prevent
                     moisture changes and heating in the stored
                     Can rust and must be repaired carefully for
                     airtight storage to be continued.

51cp44.gif (317x317)

                    STORING GRAIN IN METAL BINS
Metal bins are being tried for small-scale use in many parts of the world.
In some areas, farmers can buy metal bins in different sizes.  They are
sometimes expensive, and they rust in moist areas.   Often a farmer needs
to be a member of a credit program to get the money to buy this type of
metal silo or bin.  Then he repays the money for the cost of the bin.   Hopefully,
the bin pays for itself by reducing losses to the stored grain due
to attacks by insects and rodents.
Metal bins can also be built quite easily:   but the farmer must know how
to weld and work with metal.   Or someone with these skills must be able
to help.
     *   Built above the ground -- either
        on platforms or on
        cement bases when kept outside.
        The metal bottoms will
        rust because of contact with
        ground water if the bins are
        on the ground.
     *  Rounded in shape to hold the
        pressure of the grain better:
        a square bin would have more
        seams and be more likely to
        break open.
     *   Painted white or stored out of
        the sun because metal conducts
        (passes on) heat very well.

51cp45.gif (486x486)

Advantages of Metal Bins
     *   Good control of insects, molds, and rodents if bins are well-made,
        well-sealed, kept off the ground, and out of the sun.
     *   Small metal bins are lightweight and may be moved easily.
     *   A metal bin may pay for itself out of the farmer's increased
        profit.   This is true (for all improved storage methods) only
        where initial costs are not too high or a good credit program
        is available.
Disadvantages of Metal Bins
     *   Metal sheets for building the silo are more expensive than
        most locally available materials, or, in some areas, cement.
     *   Construction of a bin requires special equipment to cut and
        weld the metal and people trained in working with metal.
     *   Metal rusts quickly in hot, wet places.   Sheet metal for bins
        must be galvanized or painted regularly to protect the metal
        from rusting.  This is another cost to the farmer.
Blacksmiths and people with metal-working experience, who might be interested
in making bins to fit local needs,should be encouraged to try to do so.
Experimenting with various designs will give information which can help
you decide what kind of metal bin will work best in your area.
The following information on various metal bins is provided to give some
idea of what types of bins are available.   Wherever possible, an address
is included so that you may write for further information.
The bin shown here is very useful for storing small quantities of grain
indoors.  It can be made in four sizes, ranging from 500kg to 3 tons.
The chart included here gives the dimensions for each size of circular
steel bin.

51cp46.gif (486x486)

     *   Opens at the top for filling and has a spout at the bottom
        for emptying.
     *   Has a flat top and bottom made of plain Mild Steel sheets.
     *   Has circular sides made of corrugated Mild Steel sheets.
     *   Comes in 4-6 pieces which can be put together on site.  The
        bin can be taken apart when not in use and put back together
        when it is needed again.
     *   Prevents uneven temperatures within the bin by building-in
        a special arrangement.
     *   Uses neoprene washers with bolts to make the bin airtight.
     *   May be used for fumigation, as required.
     *   Can be made in any small sheet-metal workshop.
     *   Stores grain to be used for seed safely.
Capacity      Height (cm)       Diameter (cm)        Gauge Steel Sheet
500kg           125                 80                     28
1 ton           165                100                     26
2 ton           210                124                     24
3 ton           210                150                     24
For further information  on this and other  bins which might be of   use
to small farmers in your area, please write to:
       The Grain Storage Research & Training Center
       Department of Food
       Government of India
       Hapur, Uttar Pradesh
A "Save Grain Campaign," begun in India in 1965, resulted in a number of
metal bins which were designed specially for use in the home and on a
small farm.

51cp48.gif (486x486)

Two styles of bins are pictured here. Each bin is pictured in two sizes.
The following chart shows how many kilograms of paddy, maize, or wheat
each size of bin can hold.
CAPACITY                PADDY(*)           MAIZE(**)           WHEAT(***)
Cubic Meters              kg                 kg                  kg
  0.42                    230                 300                 315
  0.68                    375                 485                 510
  0.82                    450                 580                 615
  1.35                    745                960               1015
(*) Approximately 550kg per cubic meter
(**) Approximately 710kg per cubic meter
(***) Approximately 750kg per cubic meter
The specifications and technical drawings for these bins are available
in booklet form from:
       Save Grain Campaign
       Ministry of Agriculture
       Department of Food
       Krishi Bhavan
       New Delhi, India
This silo was developed by the Institute of Tropical Agriculture Research
in Benin (formerly, Dahomey), Africa.   It is a good example of an easily
made metal storage container.
The model below is made of sheet metal, 1mm thick, welded together at
the seams.  It has two openings, one for filling at the top of the bin and
one for emptying at the bottom.   The cost of the 3 ton model shown here
is about $175 (U.S. currency) when manufactured in small numbers.

51cp49.gif (540x540)

Fumigants are insecticides in the form of gas.   This gas can kill adult
insects living outside the grain kernels and larval stages living inside the
kernels.  Once the gas disappears from the grain, there is no more protection
against insects.

51cp50a.gif (57x353)

The easiest and safest fumigant to use is Phostoxin.   In many areas,
Phostoxin is relatively expensive.   You can buy it in the form of tablets
or pellets.  These formulations only start to turn into gas when they are
taken out of their containers and placed in the air.   When the moisture
from the air touches the tablets, the gas begins to form.  Phostoxin containers
must always be tightly sealed when not being used.

51cp50b.gif (200x600)

It is not a good idea for a farmer to use Phostoxin himself -- unless he has
used it before, and you are sure he understands the use of this fumigant.
But you should know how to use Phostoxin so that you can instruct and help
the farmer fumigate his grain.
So the following pages present fumigation procedures which will be most
helpful to the small-scale farmer:   fumigation for stacked grain sacks;
fumigation in plastic bags; fumigation in small metal bins, silos, and
oil drums.
*  Use 1 pellet of PHOSTOXIN for each 100kg of grain.
   Tablets contain more poison than pellets; 5 pellets are equal
   to 1 tablet.   If you cannot find pellets, you can cut one tablet
   in 4 pieces.   Therefore, one tablet will fumigate 4 bags of grain.
   You must be sure there are no little pieces of the tablets lying
   around after you cut.  If there are pieces, drop the pieces into
   a large pail of water which has soap in it.  Do this outside in
   the open air.   The gas will cause bubbling in the water.  When
   the bubbles disappear, you can throw the mixture away.
*  Use heavy gauge (500 gauge) plastic bags.
*  Make sure the bags have no holes or tears.  Mend any holes with
*  Fill a bag with grain.
*  Put the pellet of Phostoxin in an unsealed envelope or piece of
   paper and place the packet on top of the grain in the bag.
*  Close the bag and tie as shown.

51cp51.gif (600x600)

*  Place a warning on the bag so no one will touch or open the bag.
*  Leave the bag as it is for at least 5 days.  It is even better to
   keep the grain in the bag tightly sealed until it is needed.  Gas
   cannot protect against new attack, but once fumigation has killed
   any insects present, the plastic bag will maintain airtight storage
   conditions which will control insects.
   NOTE:   PHOSTOXIN may be expensive and may not be available in all
          areas.   Check with your extension agent for information on
           other insecticides which might be useful for you to use on
          your stored grain.
      3 tablets per 25 45kg bags or 1,125kg of sacked grain
      15 pellets per 25 45kg bags or 1,125kg of sacked grain.
*  Use fumigation on bags made of jute or fiber.  If using plastic
   bags, make sure the bags are open before fumigation begins.
*  Stack the sacks on the floor on a sheet of plastic, unless the
   floor is concrete.  Do not fumigate directly on the ground
   because the soil will be temporarily poisoned by the fumigant.
   If the fumigating is being done outside, stack the sacks on a
   large sheet of plastic.  Make sure the plastic is larger than
   the grain stack on all sides.
*  Take a 500 gauge plastic sheet.  The sheet must be large enough
   to cover the stack completely and be held to the ground tightly.
   If necessary, you can overlap and tape smaller sheets together
   to make a large enough sheet.
*  Check the sheet to make sure there are no holes in it.  You
   can do this by holding it up to the light.  Mend any holes or
   tears with tape.
*  Spread the right number of tablets around the sacks.  Spread
   the tablets around so that they do not touch each other.

51cp53.gif (600x600)

*  Make sure the edges of the sheet are sealed tightly.  Use loose
   sand, sand bags, poles, etc. to hold the sheet down.
*  Keep the doors and windows open if you are fumigating inside
   a building.   (This is of course true only when you are fumigating
   under a plastic sheet inside a building -- not when you
   are fumigating an entire building.  In this case, you would
   want to close the doors and windows tightly.)
*  Do not let anyone enter the fumigation area.
*  Leave the stack under fumigation for at least 5 days.  Some
   PHOSTOXIN users prefer to remove the sheet while wearing a
   gas mask.   But a gas mask is not necessary, if you follow
   these simple suggestions:  lift the plastic sheet at one
   corner using a long pole.  This means that if there is any
   gas still under the sheet, it will not hit you in the face
   when you lift the cover.  Leave the stack as it is, with
   the one corner lifted up, for 1 or 2 hours.
*  Remove the plastic sheet after 1 or 2 hours if there is
   no strong smell.
NOTE:  One characteristic of PHOSTOXIN which makes it relatively safe
       for farmers to use is the very strong smell associated with
       PHOSTOXIN.  The smell, which starts being released almost
       immediately, is a good warning to users because the smell is
       noticeable before the gas reaches a poison strength which can
       kill or hurt people.
                         CONTAINERS OR SILOS
     *   Use 3 tablets or 12 pellets of PHOSTOXIN for-each 4,400kg.
     *   Make sure the emptying chute and filling holes are sealed.  A
         thick coating of grease will make a good seal.
     *   Check to make sure bolt holes and seams of a water-tank bin
        are sealed.  You can seal these with bitumen or melted wax if
        you are not sure they are tight.
     *   If the grain level in the bin is no more than 6m, you can
        spread the tablets only on top of the grain.
     *   Spread the tablets as you pour in the grain only if the grain
        can be sealed up within 4 hours.  Remember to place the tablets
        in an open envelope.  In a larger silo, you can build up the
        grain to a level of 5m and then start putting in tablets.
        Continue putting in grain and tablets until finished.  Start
        counting 4 hours from the time the first tablets are put in.
     *   Seal the manhole just as soon as all the grain and tablets are
     *   Leave the silo unopened for at least 5 days.  If the grain is
        not needed, keep the container sealed until the grain is
               CAN KILL.
NOTE:  Metal drums are good containers in which to fumigate grain.   Simply
       drop in the correct number of pellets for the size drum, seal it
       tightly,and wait for 5 days.
Farmers for thousands of years have been storing grain in bins and other
containers made of clay.  Earth is available and easy to use.
More recently, there has been interest in improving mud granaries to make
them more airtight and waterproof.   This is especially important in areas
where insecticides are hard to get and where there is a lot of rain.
The Pusa Bin, which is discussed here, was
developed in India.  It is made of mud
bricks.  The walls are made by sealing
a layer of plastic sheet between two
layers of mud bricks.  The mud bricks
protect the plastic from holes.   The
plastic keeps air and moisture out.

51cp57a.gif (437x437)

     *   It is an airtight storage
     *   The materials are often available
     *   Plastic sheets are sometimes hard to get or expensive.
     *   It must be protected from rain by a separate roof.
     *   Sealing the plastic sheets may be a problem for a farmer.
The other plan presented here is the improved mud
silo, and is based on a plan prepared in Ghana.
VITA artist George Clark provided the illustrations.

51cp57b.gif (437x437)

The silo is made of mud bricks.   This silo was
improved by plastering and painting the walls.
Plaster is usually composed of cement, lime
and sand.  Mud plasters also can be used.  Both
mud and plaster may not stick to the brick walls
for long periods of time.  Mud plaster sticks
better for a time, but heavy rains can wash it
away.  Efforts have been made to mix the mud
with a stabilizer such as cement, or bitumen;
this seems to work.  Also, to make the plaster stick better, small stones can
be added to the mud used to make the bin walls.
Local material also can be used to paint and coat the outer walls.  Some
materials which can be tried on the walls are:
             asphalt                       resins
             organic oils                  ox-blood
These coatings last only a year or so, but they are cheap, available, and
easy to put on.  See Appendix D for information on how to find and use local
materials to waterproof soil construction.   When looking for a coating for an
improved mud silo, the farmer should remember he is looking for a material
     *   is water-repellant.
     *   sticks to the walls.
     *   lasts long enough so he does not have to re-apply often.
The improved mud silo presented here has the following advantages and
        *   The materials are cheap.
        *   Airtight storage can be achieved or nearly achieved.
           If the farmer is not sure the silo is airtight, he can
           add insecticide to the grain.
        *   The emptying chute allows small amounts of grain to
           be taken out without unsealing the top of the bin.
        *   It can be made in a number of sizes.
        *   It requires regular painting or whitewashing.
        *   It may not be water-tight to prevent grain rewetting.
Since these earthen structures seem to be more easily made by small
farmers than the metal bins, the construction plans are given in more
detail.  The mud silo presentation includes a set of instructions for
use of the silo.
                        THE INDIAN PUSA BIN

51cp59.gif (437x437)

The Pusa Bin was developed in India by members of the Agricultural
Research Institute in New Delhi.   It is relatively simple and inexpensive
to construct and maintain.  This bin is double-walled all the way round
-- including the floor and roof - with a separating layer of plastic
sheet.  The plastic protects against moisture and keeps air from entering
the stored grain.
Protect the bin from rain.  If the bin is not erected under a shed and it
rains often, it will require too much repair and rebuilding, and the grain
may get wet and mold.  However, complete shading from the sun is not
necessary because mud walls do not hold heat.   This is one advantage of
a mudblock structure over a metal bin.
In India, rats cause great storage losses.   For this reason, in this plan
the bottom 50cm of the outside wall and the first layer of the floor slab
are made of fired, or "burned," bricks.   These bricks are harder than
un-fired bricks, like mudblocks, and rats and mice cannot gnaw through the
bin walls or burrow up underneath the floor to get to the grain.  Another
way to keep out rats and mice is to use sheet metal over whatever kind of
non-hardened material you use, in the same places.
This plan uses an insulating layer of plastic sheet.   The Pusa Bin is
airtight and waterproof only if the plastic sheet is made and used
correctly.  The plastic sheet used should be at least 700-gauge thickness,
to resist tears and punctures.
If plastic sheet is not available or if it is too expensive, some other
form of waterproofing will be needed in warm rainy areas.  Check out what
is available locally.  Tarfelt -- heavy paper impregnated with tar --
can be used.  Experiment with bricks containing cement.   Try painting the
bin with asphalt, coal tar or any other local waterproofing substance.
Remember, the bottom of the bin must be waterproofed to stop migration
(seeping of moisture from the earth below.
This plan is for a 2 metric ton bin.   You may vary the size of the bin
to fit your needs.  Make sure you build a strong enough roof support
frame for larger bins.
Tools and Materials
       *   mudblocks and mud mortar for the walls.   If you make blocks
          10 x 10 x 20cm you will need about 900-1000 of them.
       *   wood to make a form for making mudblocks
       *   fired, or "burned," bricks, concrete blocks or bricks of some
          other hard, rat-proof material for the floor and lower 50cm
          of the walls.  You will need about 250 of them.
          some sheet metal to cover mudblocks for the same purpose.  You
          will need 6-6.5 square meters, allowing for overlapping of
          sections.  If you use sheet metal instead of hard bricks, add
          250 mudblocks to the number given above.
       *   cement mortar if you use fired bricks
       *   about 9 square meters of 700-gauge plastic sheet for moisture-proofing
          the bin.  Or the same area of tar-paper, or a suitable
          amount of waterproofing material to give a good, thick coating
          or several coatings.
       *   a piece of iron bar to heat and seal seams in the plastic
       *   wood or another strong material for making a roof support
       *   sheet metal or plastic pipe for an emptying spout.  Coated
          wood will also work.
       *   some wax or similar material to seal some joints
       *   mud for making roof slabs
1.     Select a site.
       *   Choose a place that is as high and dry as possible.  It is
          better to build up the earth a little for extra protection
          against collecting rainwater.  Level and firmly tamp down
          the earth.
       *   Make the foundation area at least 1.5 x 2m.
2.     Make mudblocks.
       *   Use the hard earth beneath the topsoil to make mudblocks.
          If the soil in your area does not have a high clay content,
          you may be able to mix a little cement in with low-clay soil
          to make good mudblocks.
       *  A wood form can make several mudblocks at a time.
       *   If you use blocks measuring 10 x 10 x 20cm you will need about
          900-1000 mudblocks.  If you are going to use sheet metal instead
          of fired bricks to protect against rats and mice, add 250 more.
 3.     Make the floor of the bin.
       *   Lay down a platform of fired bricks or other hardened bricks,
          and cement mortar, measuring about 120 x 160cm.
          Lay down a layer of sheet metal and place a layer of mudblocks
          and mud mortar on top of it, to the same measurements.  Use
          flattened kerosene tins or any available sheet metal.  Overlap
          all the pieces.  Make the outside edges stick out about 15cm
          beyond the outside edges of the block platform that will be
          laid on top of it.
       *   Allow about 1cm thickness of mortar between either kind of
          brick, for a good bond.
       *   Place a layer of plastic over the bricks, or whatever waterproofing
          material you are using.  It should extend a few
          centimeters beyond each edge of the layer of bricks.
       *   Lay down a layer of mudblocks and mortar on top of the plastic,
          the same size as the first brick layer.

51cp62.gif (486x486)

4.     Build the inner walls.
       *   The inner walls may be made entirely of mudblocks and mortar.
       *   Make the outside edges of the walls the same as the outside
          edges of the floor.
       *   Build an emptying spout into the first layer.  Form something
          like galvanized tin into a tube about 9 or 10cm in diameter,
          or use a plastic pipe the same size.  Fit one end flush against
          the inside of the wall.  Make it long enough to extend past
          where the outside edge of the outer wall will be.  You may
          tilt it downwards slightly towards the outside for easier exit.
          Mortar it into the wall.  You will need a tight-fitting cap
          on the end of the spout.
       *  Lay the blocks so that each one crosses over a joint between
          blocks in the layer below it.  This will make the walls stronger.
       *   Build the walls to a total height of about 160cm -- but wait
          until installing the roof support frame (next step) before
          putting in the final layer.

51cp63a.gif (486x486)

5.     Install a roof support frame.
       *   Use wood that is naturally termite proof, or coat it with
          something to protect it against these and other insects.
          Metal or reinforced concrete bars can be used, but they will
          be more expensive.  The roof must have strong support:  use
          the best available material.
       *   Use four pieces as long as the distance between the outside
          edges of the inner wall -- two pieces about 120cm and two about
          160cm. Wood should have at least a 5 x 5cm cross section.
       *   Form the frame in a double-cross
          pattern.  Interlock wood joints.
          One of the corner spaces should
          measure about 50 x 50cm, for a
          manhole entrance.

51cp63b.gif (486x486)

       *   Position the frame on top of the
          next-to-last layer of blocks in
          inner wall.  Raise the ends up
          on some mortar so the top surface
          of the frame will be at the same
          height as the top surfaces of the
          final layer of mudblocks.

51cp64.gif (486x486)

       *   Mortar the frame and the blocks for the top layer of the wall
          into place.  Make a smooth top surface on the walls.
6.     Build the inner roof.
       *   Make mud slabs 5cm thick for the inner roof.
       *   You may make one or more to cover each space in the support
          frame, depending on how strong the slabs are.  They will have
          to support another layer of mud slabs the same thickness when
          the bin is complete.  It would be best to extend them to the
          outside edges of the inner wall for firm support.  Sections of
          tightly stretched wire mesh fastened to the support frame
          would provide extra support for the slabs.
       *   Position the slabs on mortar applied to the support frame and
          the tops of the walls.  Leave the 50 x 50cm manhole open.
       *   Fill any spaces between the slabs with mortar.
7.     Plaster the inside.
       *   Plaster the insides of the walls and the roof, and the surface
          of the floor with a smooth coating of mud or mortar.  This will
          leave no place for insects or dirt to lodge.
8.     Make and install a plastic cover.
       *   Measure the outside dimensions of each of the four walls and
          the roof.
       *   Cut pieces of plastic sheet to cover each of the five surfaces.
          Each piece should be cut a little larger than the surface
          which it will cover -- at least 5cm overhang on each edge.
          The bottom edges of the sides must reach a few centimeters
          beyond the plastic sticking out from the floor.
       *   Fasten the pieces together in a box shape.  Keep in mind the
          right arrangement of pieces so that when the cover is placed
          over the bin it will fit.
       *   Seal the edges of the plastic together with a heated piece of
          iron bar.  Lay one edge over another and pass the iron over
          them.   Make sure the iron is not too hot:   it should not melt
          the plastic, but just seal it together.  Make sure you have a
          good seal.  Practice making seams on small scraps of plastic
           first.   Find the right temperature for the iron.

51cp65.gif (486x486)

       *   Make sure there are no rough edges of blocks or mortar on the
          walls or roof that will damage the plastic.
       *   Pull the cover all the way down over the inner structure of the
          bin.   If it is too small you will have to re-make it; you may
          be able to re-work the seams.  It does not matter if the cover
          is too large.
       *   Cut a hole in the plastic around the emptying spout.  Seal it
          to the spout with something like soft wax.  This should make
          an air- and water-tight seal.
       *   Seal the bottom edges of the wall pieces to the edges of the
          plastic in the floor.
       *   Cut a diagonal slit through the plastic across the manhole.
9.     Build the outer walls.

51cp66.gif (486x486)

       *   Begin the walls from the earth foundation.  Build them right
          up against the plastic over the inner walls.
       *   Use fired bricks or other hardened bricks and cement mortar for
          the lower 50cm of the outer walls
       Use mudblocks and mud mortar instead, building them up on the
       metal sticking out from under the floor.  Cover them to a height
       of 50cm with overlapping pieces of sheet metal.  Mortar or
       otherwise securely fasten the metal in place.  Make a good joint
       with the metal sticking out from under the floor.
       *   Continue the outer walls with mudblocks and mud mortar.
          Build them up to the top surface of the inner roof.  If
          there is any difference in height, fill with mortar.
10.    Build the outer roof.
       *   Place 5cm-thick mud slabs over the plastic sheet on top of
          the inner roof, mortaring them in place, out to the outside
          edges of the outer walls.  They may be any size across, as
          long as they are strong.
       *   Do not cover the manhole.   Make a separate mud slab to fit
          over it.
       *   Fill in spaces between the slabs with mortar.
11.    Finish the bin.
       *   Plaster the outer roof and sides with a smooth layer of mud
          or mortar.
       *   Let the entire structure dry thoroughly.  This will take about
          thirty days.  Leave the manhole cover off during the drying.
       *   A coat of whitewash put on after drying would help reflect the
          sun's heat and add further waterproofing.
       *   Build a shelter over the Pusa Bin to protect if from the rains.
          Make it at least a half meter larger than the bin on all sides,
          and high enough to give plenty of room to load grain and get
          in and out the manhole.  There is no need to enclose the sides
          of the shelter.
12.    Prepare and use the bin for storage.
       *   When the bin is dry, clean the inside thoroughly.  Light a small,
          smoky fire to drive off insects.  Take both of these steps each
          time you get ready to load an empty bin.
       *   Dusting the inside surfaces of the bin with insecticide, and also
          the grain, will protect the grain better.
       *   Cover the manhole when you have put your grain into the bin.
          Seal it with extra mud or mortar for more protection.
       *   Always close the cover of the emptying spout tightly after using.
       *   Check the grain periodically.
       *   Store only grain which is dried to 12-13% moisture content in
          the Pusa Bin.
                        IMPROVED MUDBLOCK SILO
Tools and Materials
       *   Rocks about 20-25cm across for the foundation of the silo.
       *   Flat rocks, as wide across as possible, to lay across the
       *   Sand for concrete and mortar.
       *   Small stones to mix in with the concrete.
       *   2 bags of cement.
       *   Trowel or a similar tool to work the mortar and plaster
       *   Different sizes of wood boards. The sizes are shown in
          each part of the instructions where you will use them.
       *   Earth to make mudblocks.
       *   Nails (1.8-2.4cm long).
       *   Pitch, tar, or other waterproofing
Select a Site
       *   Find some solid ground on which
          to build the silo.
       *   High ground is best.
       *   Make sure the silo is built in
          a place where the ground underneath
          it will not wash away
          during a rainy season.

51cp69.gif (486x486)

1.  Make a Form to Mold Mudblocks
       *   Use wood boards about 2.5cm thick.
       *   You will need:   2 boards 46cm x 10cm
                          4 boards 10cm x 15cm
       *   Line the 2 long boards up side by side.
       *   Nail the 4 small boards crossways between them.  Place the
          small boards so that the distance between the 2 long boards
          is 15cm. Leave  10cm space between each of the small boards.
          Place the first small board about 2.5cm in from the ends
          of the long boards. This should leave about the same amount
          of space on the other end.
       *   Make handles.   Use 2 small pieces of wood 2.5cm thick that
          are 15cm long and about 5cm wide. Nail one across each
          end of the box.
2.  Make Mudblocks
       *   Mix earth and water to make the same kind of mud you use to
          build any building.
       *   Wet the form.
       *   Fill the form with mud.
       *   Pack the mud tightly into
          the form.
       *   Take any extra mud off the
       *   Lift the form carefully off
          the mudblocks.
       *   Dry the blocks in the sun.
       *   Make about 300 blocks.  

51cp70.gif (587x587)

3.  Make Frame "A" for the Outside of the Topslab
       *   To make this topslab you must make 4 wood
          frames.  Later you will pour concrete into
          these frames.

51cp71a.gif (437x437)

       *   Prepare:  2 boards, 2.5cm x 5cm x 1.2m
                    2 boards, 2.5cm x 5cm x 1.1m
                    4 boards, 2.5cm x 5cm x 51cm
       *   Nail the 4 longer boards together.   Butt
          the ends of the 1.1m boards up against the ends of the 1.2m
          boards.  When the frame is lying on the ground,the 2.5cm edges
          of the boards should be facing up.
       *   Nail these cross pieces in place from the inside.  The 2.5cm
          edges of these boards should also be facing up when the frame
          is lying on the ground.
       *   Cut the ends of the 4 short boards at a 45 degree angle.
          Then they will fit easily across the corners of the large
          square frame.

51cp71b.gif (600x600)

4.  Make Frame "B" for the Manhole
       *   Prepare:  2 boards, 2.5 x 8cm x 45cm
                    2 boards, 2.5 x 8cm x 40cm
       *   Cut part of the face off each end of the 4 boards.
          This will make a slanted face.
       *   Nail the 4 boards together.   Face the slanted sides outward.
          Butt the ends of the 40cm boards up against the
          ends of the 45cm boards.

51cp72.gif (486x486)

5.  Make Frame "C" for the Collar
       *   Prepare:  2 boards 2.5cm x 2.5cm x 53cm
                    1 board, 2.5cm x 2.5cm x 56cm
                    1 board, 2.5cm x 2.5cm x 66 cm
       *   Nail the 4 boards together. Butt the ends of the 56cm board
          up against an end of each of the 53cm boards.  Butt the other
          ends of the 56cm boards up against the 66cm board.  Leave 5cm
          of the 66cm board sticking out on one end.

51cp73a.gif (486x486)

6.  Make Frame "D" for the Manhole Cover
       *   You will need:   2 boards, 2.5cm x 5cm x 61cm
                          2 boards, 2.5 x 5cm x 56cm
       *    Nail the 4 boards together.   Butt the ends of the 2 shorter
           boards up against the ends of the 2 longer boards.

51cp73b.gif (486x486)

7.  Mix the Concrete and Pour it into the Wood Frames
       *   Mix the concrete in a proportion of:   1 part cement (out of the bag)
                                                2 parts sand
                                                3 parts small stones
          Remember to mix the dry ingredients first.  Then add the water,
          a small amount at a time until the mixture is correct.
       *   Cover a flat place on the ground with empty cement bags or
          sheets of heavy paper or plastic. These will keep the concrete
          from sticking to the ground.
       *   Wet the empty bags or whatever you are using. This will keep
          the concrete from sticking to them.
       *   Put Frame A on top of these.
       *   Place Frame B in the middle of Frame A.   Make sure each side of
          Frame B is the same distance from each side of Frame A.  The
          thin edges of Frame B should be facing down.
       *   Begin pouring concrete mix into the space between Frame A and
          Frame B.  The open space inside of Frame B will be the manhole.
       *   When you have poured in about half the thickness all the way
          around, lay in the metal rods.
       *   Pour the rest of the concrete mix over the rods.
       *   Make sure the rods are in the concrete.   They should not show
          through the concrete.  If you do this right, the rods will help
          make the concrete much stronger.

51cp74.gif (486x486)

       *   Level the concrete even with the top of Frame A.  Frame B will
          stick up 2.5cm above the wet concrete.
       *   Place Frame C around Frame B on top of the wet concrete. The
          space between the two frames must be the same on every side.
       *   Pour concrete mix into the space between Frame B and Frame C.
          Make the top of the concrete level with the tops of the 2 frames.
          This will form a collar for the manhole cover to rest on.
       *   You are now ready to use Frame D to make a separate piece.  This
          will be the manhole cover.
       *   Place Frame D on some empty cement bags or sheets of heavy paper
          or plastic.
       *   Wet the empty bags or whatever you are using.
       *   Pour concrete mix into Frame D.  Level off the top of the concrete
          to the top of the frame.
       *   Leave all the frames around the concrete for at least 3 days.
          The concrete will become even stronger if you can leave it for
          several more days.
       *   While the concrete is drying, put water on it 3 times each day
          at morning, noon, and night.  Putting water on the concrete like
          this will make it harden evenly and not crack.  This is called
       *   When the concrete is   Cured," remove the wood frames.   Remove
          them carefully, so you can use them again.

51cp75.gif (486x486)

8.  Make the foundation
       *   Draw a circle on the ground where you want to build the silo.
          Make the circle 1.2m across.
       *   Place the 20cm or 25cm rocks around the circle just inside the
          edge, and inside the circle.  You may fill in the larger spaces
          with smaller rocks to give more support.  The air spaces between
          the rocks will let air move through the foundation and will
          keep moisture from collecting.
       *   Place flat rocks on top of the circle of rocks.  This will make
          the top more level.
       *   If you cannot find good flat rocks, you may use concrete blocks.
          Place them the same way as you would the flat rocks.  Place
          them so they come right up to the edge of the circle of rocks,
          or overhang slightly.
       *   Make some mortar by mixing 1 part cement and 5 parts sand together.
          Add enough water to make a workable paste.
       *   Put mortar over the flat rocks or blocks.  Fill all open spaces.
          Make the surface as smooth as you can.  This will cement the
          top of the foundation into a solid piece.
       *   Find the center of the foundation.
       *   Mark off a 91cm diameter circle from the center.  This is the
          inside diameter of the silo.
9.  Build the Grain Chute (Optional)
       *   Use hard wood about 2.5cm thick.
       *   Prepare:  1 board, 2.5 x 15 x 30cm -- for the top of the chute.
                    1 board, 2.5 x 15)(25cm - for the bottom of the chute.
                    2 boards, 2.5 x 10cm that are 25cm long on one edge and
                               30cm long on the opposite edge.   These are
                               for the sides of the chute.
                    1 board, 2.5cm thick, at least 13cm wide,and 20cm or
                               25cm long.   This is for the sliding door
                               in the chute.
       *   Place the edge of the sliding door board on one of the side boards
          5cm in from the short straight end.  Trace the width of this edge
          onto the side board.  Make a groove.   Remove the wood between the
          2 lines you have traced to a depth of about 6mm.  Make each
          surface of the groove as smooth and as straight as you can.
       *   Repeat this process on the other side board.  The groove should
          be in the same place on each side board.

51cp77.gif (600x600)

       *   Cut the top board into two pieces.   One piece should be 5cm
          long.   This will fit the space between the front of the chute
          and the beginning of the groove for the sliding door.  Match the
          edge of the remaining piece with the far end of the groove.  Cut
          the length of the top piece as needed to match the length of the
          side piece.
       *   Nail the top and sides and bottom of the chute together.
       *   Trim the width of the sliding door board so that it will slide
          through the opening in the top of the chute down the grooves.
       *   You may have to trim the long sides of the opening too if the
          sliding door is too thick.  The sliding door should move freely
          up and down but should not be too loose.
       *   Cut the bottom edge of the sliding door at an angle so that only
          a thin edge will touch the bottom of the chute.  This edge will
          face the outside of the silo.  This will make it easier to keep
          grains from lodging under the closed door which might let air
          and moisture and insects into the silo.
       *   Paint the chute and the sliding door with pitch or tar or some
          like material to protect it from insects and moisture.
       *   Drive a few nails into the chute near its slanted end.  They
          should stick out a couple of centimeters.  The nails will
          help anchor the chute into the walls of the silo.
10.  Begin the Walls
       *   Make mortar the same way you did for the top of the foundation.
          It is better to mix smaller amounts until you know how fast you
          can use it.  Do not use mortar that has gotten too dry because
          it will not be as strong.
       *   Lay down a layer of mortar all around the inside edge of the
          circle you have drawn on the top of the foundation.  Make it
          about 10cm wide.
       *   Place about 18 mudblocks in a circle on top of the mortar.  Leave
          a space for the chute, including the nails that are sticking out
          from it.
       *   Place the chute in the space you have left.  The slanted end of
          the chute should be even with the inside surfaces of the blocks
          next to it and straight up and down.   This will make the
          chute tilt down away from the silo wall.

51cp78.gif (486x486)

       *   Fill the spaces between the mudblocks and the spaces between the
          mudblocks and the chute with mortar.
       *  Lay down a layer of mortar on top of the circle of mudblocks.
       *   Place the second layer of mudblocks on top of the first.  Place
          each block so that it lays across the space between the blocks
          in the first layer.  This will make the wall stronger.  You
          may have to cut blocks to fit next to the chute.  Do not leave
          a large space that will have to be filled with mortar next to
          the chute.
       *   Continue putting on mortar and mudblocks in the same way until
          you have laid down 4 layers of mudblocks altogether.
11.  Make a Slanted Floor
       *   Use sand or soil to make a slanted floor.  This will help the
          grain move towards and out of the chute.  If the chute is not
          used, this slant will not be needed.

51cp79.gif (486x486)

       *   Pack the sand or soil down
       *   The floor should be 30 cm
          above the bottom of the
          chute at the place opposite
          the chute.  The floor near
          the chute should be even
          with the bottom of the
       *   Make a mix of plaster.   Use
          1 part cement (out of the bag)
          to 3 parts clean sand (mix dry).
          Use enough water to make a
          smooth mix.   Do not make it
          too watery.
       *   Plaster the slanted floor and
          the inside of the mudblock wall.
          Make sure you cover all the
          surfaces completely.
       *   Plaster carefully around the
       *   Smooth the plaster well after you put it on. This will make cleaning
          easier and will leave fewer spots for insects to hide in.
       *   Keep the plaster damp until it is hard.
       *   Put loose sand on the floor after it is dry.  This will keep
          drops of mortar and plaster from sticking to the floor as
          you continue working.
12.  Finish the Walls
       *   Tie a string to a small stone.   You will use this to check
          the straightness of the walls as you build them.
       *   Put down 3 or 4 layers of blocks.   Use mortar and arrange the
          blocks the same way you did for the first 4 layers.
       *   Hold the string at the top end, with the stone hanging down
          from it at the other end.
       *   Hold the string out about 5cm from the top of the silo wall.
          The silo wall is straight if the distance between the string
          and the wall is the same from the top to the bottom.
       *   Continue adding layers of blocks the same way as you did before.
          Check every 3 or 4 layers for straightness.
       *   The finished silo wall should have about 14 layers of blocks.
       *   Mix some plaster the same way you did for the slanted floor
          and the inside of the first 4 layers of mudblocks.
       *   Plaster the inside and the outside of the silo wall.  Remember
          to put the plaster on very smooth.
13.  Place the Topslab
       *   When the mortar and the plaster in the silo wall are dry and
          strong, you are ready to place the topslab on top of the silo.
       *   Make sure that Frames A, B,and C are removed from the concrete
       *   You will need people to help you put the topslab in place.
       *   Mix some fresh mortar (1 part cement, 5 parts sand, and water).
       *   Place a layer of mortar all around on top of the silo wall.
       *   Put the topslab down on top of the mortar.  Many people can
          lift the topslab together.  One person can stand inside and
          help.   He can get out through the manhole.
       *   Remove the cover from Frame D and place.

51cp81.gif (486x486)

14.  Whitewash the Silo
       *   Apply a coating of whitewash to all the outside surfaces of
          the silo.   The manhole cover and all areas of the topslab and
          walls should be covered.
       *   Whitewash closes small openings in the cement.
       *   Whitewash helps keep the silo cooler inside.  It is important
          to keep the grain cool and dry.
       *   Whitewash will also make your silo look nice.

51cp83.gif (486x486)

       *   Put only clean, dry grain into your silo.
       *   Wet grain will rot in the closed silo.   It will
          get moldy.
       *   Wet grain will make the silo wet.   The silo walls
          will crack if they get wet.  Your grain will be
          no good.
       *   Dry your grain in the sun.
       *   Keep the grain in the sun or in the dryer until
          it is dry.
       *   Test the grain when you think it is dry.  Put
          one grain between your teeth.  Dry grain is very
          hard to break with your teeth.
       *   Remember, if storing maize -- put kernels into the silo right
          after you remove them from the cobs.  Do not let maize stay on
          the cobs after you remove the maize from the drying place.
       *   When the grain is dry, take the cover off the manhole.  Put the
          grain into the silo right away.  Fill the silo to the top.
       *   Stir the grain in the silo with a large stick.  This helps the
          grains settle.
       *   It is good to add an insect poison to the grain before you close
          the silo.  Insects are always present in grain.  Insect larvae
          live inside the kernels where they can not be seen.  Talk to
          your extension worker about what poison to use and how to use it.
       *   Remember, poisons can kill animals and people.  Do not use them
          before you talk to an extension worker.
       *   Put the cover on the manhole as soon as possible.  Flying
          insects can enter the grain if the cover is not on the manhole.
       *   Put mud all around the cover so nothing can get into any cracks
          between the cover and the manhole.
       *   Make sure the sliding door in the wooden chute closes tightly.
       *   Make sure there are no cracks around the chute.
       *   Put mud over the chute to protect it from rodents and insects.
       *   Keep the area around the silo clean.   Rats do not like to
          live where it is clean.
       *   Check your silo often.   Put new plaster on any cracks you
          find.   It is important to find the cracks and put plaster
          on them right away.
       *   Keep the silo white.   The white color keeps the silo cool.
          Put on new whitewash when the silo needs it.
       *   You may have to use the chute to take out small amounts of
          grain to sell or eat.  Make sure you close the sliding door
          carefully.  Do not leave it open.  Reseal it with mud.   If
          theft is a problem, the chute can be omitted and grain will
          be removed from the top of the silo.
       *   Do not leave grains scattered on the ground.   These grains
          will attract insects and rats.
       *   When you empty the silo, make sure all the grain is out.
          Grain left in an empty silo will attract insects and rodents.
       *   Clean the silo well before you fill it again.   You can burn
          a small fire made of grass inside the silo.  This kind of
          fire makes a lot of smoke.  The smoke and heat from the
          fire kill insects and insect eggs.
       *   Sweep out the ashes, dust, and old grain.
       *  When your silo is clean and repaired, you are ready to put
          the next crop of grain into the silo.
Materials in this section have been adapted from articles in Ferrocement:
Applications in Developing Countries., National Academy of Sciences,
Washington, D. C., Feb., 1973; and from "Hermetic Storage of Rice for
Thai Farmers by Smith, Boon-Long, Loo, Nutalaya and Pataragetvit, Thai
Journal of Agricultural Science, July, 1971.
Ferrocement is a kind of reinforced concrete.   Ferrocement is made of
wire mesh, sand, water, and cement.   It is strong and durable.   Generally,
ferrocement structures are from 1cm to 5cm in thickness.  The reinforcement
is layers of steel mesh with thin steel reinforcing bars placed
between the layers.  Ferrocement has been used as a material for building
boats for many years.  Now ferrocement is being used with increasing success
for grain storage in a number of countries.
Ferrocement is appropriate for building structures in many areas of the
       *   The materials to make it are usually available all
          over the world.
       *   It can be made into almost any shape.   Therefore, an
          improved structure can be made which looks very much like
          the old one.
       *   It is cheaper than a metal bin, in some places.
       *   Building with ferrocement does not require a lot of
          equipment or machinery.
       *   It can be built almost anywhere, even in isolated locations.
       *   It does not take very long for workers to learn to use
       *   It needs little maintenance after completion.  Repairs,
          if necessary, are easy to make.
Reinforcing Mesh
Many kinds of mesh will work as long as the mesh can be shaped easily (is
flexible).  The mesh will have to be more or less flexible depending upon
the shape of the final ferrocement product.   If the ferrocement is to be
a rounded structure, the mesh has to be more flexible than it would have
to be for a straight-sided container.
For grain storage uses, chicken wire can be used as reinforcing mesh.
Chicken wire is usually available, though in some areas it can be expensive.
In cases where chicken wire or wire mesh is not available, the mesh can
be made by using straight wire.   This allows the user to make the size
mesh he wants, and it is cheaper to buy coils of straight wire than it
is to buy mesh.  The mesh does not need welding; either galvanized or
non-galvanized wire can be used.
Cement, Sand, and Water
Almost any ordinary cement can be used.   The sand should not be too fine
(have too many tiny pieces).   If there are pieces of dirt, leaves, or
other organic matter in the sand, wash the sand before using it.  The
water also must be free from silt and other dirt.   These materials weaken
the ferrocement if they are left in the sand and water.
There are three areas in ferrocement construction which are particularly
Mixing the Mortar
A general mix is 1 part cement to 2 parts sand.   Only enough water is
added to make a pastelike mixture.   Experience will be the best way to
find out the best consistency for the mortar.   Machines can be used for
mixing, but hand mixing the mortar works very well and may cost less.
Putting the mortar on the wire mesh
Before mixing the mortar, the mesh structure should have been formed in
the shape desired.  Then, using fingers and trowels, push the mortar into
the mesh structure.  Some kind of vibrating movement helps push the mortar
into the mesh and packs it in better.   For grain storage purposes, just put
a handle on a piece of wood and create a vibrating movement.
When placing the mortar, there are two important points to keep in mind:
you must completely cover the steel wire mesh with mortar so that the
steel cannot rust and lose its strength; at the same time, the wire mesh
should be as near the surface as possible.   This means that the covering
over the wire mesh must be thin but complete.
Curing the Mortar
Ferrocement must not dry too quickly.   It should be kept moist for at
least seven days.  It also must be protected from sun and wind.  Both
too much sun and too much wind will dry the ferrocement too quickly:
ferrocement must dry slowly to be strong.
There are many things about ferrocement which make it good for grain
storage; it is particularly good in areas of the world where high temperatures
and damp air cause grain to rot and mold easily.   (However, if wire
is very costly, and cement powder relatively inexpensive, the farmer may
want to build a cement stave silo.)   Ferrocement:
       *   can provide watertight storage, if treated.
       *   can be made to provide airtight storage, and, therefore,
          insecticides are not needed.
       *   does not heat the stored grain as much as metal bins do.
One major disadvantage to ferrocement at the moment seems to be that the
use of ferrocement for grain storage is still new, and knowledge of the
technique is not widely available.   Also, for the small farmer, ferrocement
is relatively expensive.
This section on ferrocement provides an introduction to ferrocement as
a building material for grain storage uses.   It includes descriptions of
ferrocement bins and a ferrocement lining for underground storage pits.
The Thai Ferrocement Silo (Thailo), which can hold 3.5 tons of paddy rice,
is presented in some detail.
Ferrocement has been used to make water tanks for a number of years.  But
ferrocement is still being tested for its grain storage value and much of
this knowledge is still in the hands of designers and testers.  Hopefully,
by reading the above general material on ferrocement, and, then, by
reading the following descriptions of possible grain storage uses, you
will be able to form some ideas as to whether or not ferrocement is worthy
of more investigation for use in your area.
                      THAI FERROCEMENT SILO (THAILO)
Tools and Materials
       *   Cement                      1,000kg
       *   Sand                        1,725kg
       *   Aggregate                     965kg (used in the base)
       *   Mortar plasticizer              2kg
       *   Sealant for base                5kg
       *   Paint                       0.75kg
       *   Chicken wire                   2 Rolls
       *   No. 2 rod                      80m
       *   Water pipe (19mm dia.)         32m
These are materials available in Thailand; they may not be easy to find in
other places.  But other materials may be substituted.  For example, the
silo has been built using bamboo poles instead of water pipe.  The pipe was
substituted to prevent termite infestation.   If it is not clear that termites
will be a problem, experimenting with other available materials will be
needed.  Using bamboo, means the walls will be much thicker -- 5 to 7.5cm --,
requiring more cement.  Walls using water pipe are only 4cm thick.
The sealant is to help protect the silo in areas where flooding is a
problem.  Any kind of asphalt seal should provide protection.
1.  Build the Base
       *   The base is saucer shaped and can be built on a pile of hard
          earth.   This should be done if the area has seasonal flooding
          or very heavy rains.  The base can be changed easily to fit
          different ground conditions.
       *   Put a sealing mortar on the earthen base and apron.  Make the
          mortar using, by weight:  1 part cement
                                    3 parts sand
                                    0.6 parts water
       *   Lay one layer of concrete over the apron and base.  Make it
          5cm thick.
       *   Reinforce this concrete layer with 19mm wire mesh.  (Chicken
          wire can be used) after you have laid down half the thickness
          of concrete.  Use this concrete mix, by weight:
                        1 part cement
                        1.5 parts sand
                        2 parts aggregate
                        0.33 parts water.
    *   Let this layer of concrete harden and water it 3 times a day.
       Keep the concrete damp for 7 days.  This lets the concrete
       harden slowly, and the concrete will, therefore, be stronger.
       Treat the concrete with an asphalt seal.  In Thailand, a brand
       called Flintkote is used in 2 coats.  (Flintkote is simply a
       bitumen emulsion).  The first coat is mixed with water -- 1
       part Flintkote, 3 parts water.  The second layer contains no
    *   Put down another layer of 5cm thick concrete with mesh reinforcement
       (about midway in its thickness).  This time put the concrete
       over the base, but not over the apron.  The mesh should
       stick out of the concrete to the end of the apron.  It will
       be used later as more reinforcement for the walls.

51cp89a.gif (300x600)

2.  Build the Wall Support Structure
       *   The walls slope inward towards the top in a cone shape.  The
          opening at the top of the cone is the entrance, or manhole.
       *   Build a wooden "tree" to support
          the wall structure until it is
          finished.  The tree should stand
          about 2m high with a circular
          platform at the top.

51cp89b.gif (353x353)

    *   Extend steel water pipes or whatever reinforcing materials are used
       from the base to the tree platform at regular intervals.  These
       pipes, called struts, form the support for the wire mesh.

51cp90a.gif (437x437)

       *   Bring mesh up from the base and fasten to struts with
       *   Wire horizontal hoops of reinforcing rod to the struts.
       *   Put one layer of wire mesh on the outside surface and
          one layer of wire mesh on the inside.
       *  Fasten mesh, reinforcing rod, and struts together with
          short pieces of wire threaded through the wall and
          back.   Tie by twisting the ends with pliers.

51cp90b.gif (486x486)

3.  Apply Mortar
       *   Hand mix the mortar in the following proportions, by weight:
                          1 part cement
                          1.75 parts sand
          Enough water to make a thick paste.
       *   Work the mortar into the mesh structure using trowels and
       *   The wall thickness inside and out should be about 4cm (if
          using steel pipes) and 5-7.5cm (if using bamboo).
4.  Make the cover or Top
Here are 2  choices for the top.
       1.   Ferrocement outer cover with gaskets of rubber which act
           as airtight seals.  This can be made on site or erected
           before cementing the walls.
           An inner lid can be used.  This lid can be an aluminum trash
           can lid.  If this inner lid is used, place a polystyrene (plastic)
           lining between the grain and the trash can lid to insulate
           against heat and prevent moisture condensation.
       2.   Build a small piece of formwork supported by wires attached
           to the tops of the steel pipes which form the struts for
           the wire mesh.  Or long nails can be driven into the wooden
           platform which supports the struts.  These nails are bent
           up to shape a form.
           The topseal consists of 2 parts:
           *  Aluminum lid with polystyrene insert and a tubular
              ring of plastic placed between the lid and the wall.
           *   A piece of sheet metal screwed to the top with a
              sealing gasket.
Some General Notes on Ferrocement Silos
IMPORTANT:  Do not mix too much water into the mortar and concrete
IMPORTANT:  Wet the finished ferrocement 3 times per day for 7 days.
            Cover the silo with moist sacks and make sure the cover
            is kept wet.  It is very important not to let the sun and
            wind dry the silo too quickly.  Slow drying, called curing,
            gives cement its durability and strength.
 *   Painting the silo with chlorinated rubber-base paint, coal
    tar or bitumen should be done to make sure it is completely
    airtight and watertight.
*  Fill the finished silo with water for one week if you wish to
test it.  Water is heavier than the stored grain.  If there
are cracks or weak places they will leak.   Make repairs
as needed.  The silo must be dried for 4-6 weeks particularly
if it has been filled with water.   Remember that the shape
and size of the ferrocement silo can be changed to fit your
own needs.
This material is adapted from Ferrocement:   Applications in Developing
Countries, National Academy of Sciences, Washington, D. C., Feb., 1973.
The illustration is from a report prepared by R. A.   Boxall for the United
Kingdom Committee of the Freedom from Hunger Campaign and Christian Aid,
A traditional pit can be made into an air and watertight grain storage
container by using ferrocement to line the pit.   Ferrocement linings work
even in pits built in very wet ground.   The cost of this pit was $20.00
(U. S. currency) in 1972.

51cp93.gif (600x600)

Here is an outline of the construction process.
1.  Clean the pit
       *   Remove trash
       *   Make sure walls are smooth and free of termites.
       *   Apply poison to kill termites if necessary.
2.  Prepare the floor of the pit
       *   Lay down a 10mm layer of hardcore.
       *   Lay a layer of concrete on top of the hardcore.  Use a
          concrete mix like the one given for the base of the
          Thailo grain store pits.
3.  Make the mortar
       *   Mix well one part cement and 3 parts sand.
       *   Add as little water as possible to make a paste.
4.  Line the walls
       *   Use hands and trowels to put a 2.5-3cm layer of mortar to
          the walls.
       *   Place wire mesh reinforcement, or chicken wire on the surface
          of the mortar where it is wet.
       *   See waterproofing material before placing the second layer
          of mortar.  The other method of waterproofing is cheaper,
          requires less labor and may work well depending on the
          ground water level.  This method uses a single layer of
          bitumen between the two cement layers.  If you choose this
          method, Step 6 is not necessary.
       *   Put another layer of mortar on top of the chicken wire.
5.  Cure the lining
       *   Keep the walls and inside of the pit damp for at least 5 days.
          Seven days is better.
       *   Do not let the pit dry out quickly!
6.  Waterproof the lining There are 2 methods.  Here is the most expensive.
       *   Brush off any loose concrete with a wire brush.
       *   Use a stiff brush to put on a first coat of Bitumen Emulsion.
          This first coat is diluted -- 1 volume of emulsion to 1 volume
          of water.
       *   Make sure the emulsion gets worked deeply into the lining.
       *   Let this first, or priming coat, dry.
       *   Apply a layer of undiluted Bitumen Emulsion and let dry.
       *   Mix 1 volume of water to I volume of cement to 10 volumes
          Bitumen Emulsion and brush this over the entire inside of
          the pit.
7.  Make the-lip
       *   Build up the mouth of the pit using stones.
       *   Mix concrete of the type used at the bottom of the pit and
          lay a sloping lip at the mouth of the pit as shown in the
          drawing.  Drain pipes can be used to carry water even
          further away.
       *   Let dry well.
8.  Seal the pit
       *   A traditional lid can be used.
       *   A metal or concrete lid which is sealed with bitumen makes
          a very airtight storage container.
       *   If you choose to use a metal lid place old cloths or sacks
          between the top of the grain and the cover.  This cloth will
          absorb any moisture which forms on the metal lid.
From a VITA Volunteer in India come the following ferrocement specifications
and drawings.  Since these grain bins are presented in sizes
suitable for use by small farmers, they are included here to illustrate
further the ranges of ferrocement shapes and applications.  These plans
were proposed by the Keetaram Agricultural Services, Pvt., Ltd., of New
Delhi, India.
Ferrocement Grain Bin #1 (CB-1)
Useful for seed storage or where smaller batches of various types or
qualities of grain have to be preserved.   For indoor use, although the
design will permit long exposure to sunshine and rain without deterioration
of the contents.
The bin has an internal diameter of 750mm and is 1 metre tall.  A large
manhole, 600mm in diameter, is used for loading and unloading of grain.
This manhole is closed by means of a loose fitting over which is equipped
with a facility for padlocking.   The bin can be easily sealed by caulking
wet clay all around the cover.   Since the bin will be placed directly
on the floor no opening is considered necessary at the bottom, since this
will make the extraction of grain at ground level a very tedious operation.
The height of 1 metre makes it easy for the grain to removed from the top
The walls of the bin are 12mm thick and have a smooth internal finish
preventing lodging of any bacterial infestation.   All corners and edges
are rounded off for the same reason and to facilitate cleaning of the
bin before loading.
This bin holds 0.4 cubic meters.   It will store 350kgs of wheat.  The
bin weighs about 230kg when empty and 580kg when full.

51cp96.gif (353x353)

Ferrocement Grain Bin #2 (CB-2)
This has an internal diameter of 1,000mm and a height of 1,500mm.  A manhole
diameter is provided at the top for loading of grain.   The manhole
can be closed by means of a loosely fitting manhole cover with a padlocking
arrangement.  At the bottom of the bin a square opening is provided and
this is fitted on with nuts and bolts on to the recessed enclosure of the
opening.  This cover will be normally opened once a year, when the bin
has been emptied and is to be thoroughly cleaned before fumigation.
For unloading grain, there is a 8cm diameter sheet metal screw conveyor
fitted over the cover.  This is manually operated and is estimated to
discharge at the rate of about 15kg per minute by manually turning the
conveyor at 60 RPM.
The capacity of this bin is 1.4 cubic meters.   It will store 1,000kg of
wheat.  The bin weighs 340kg when empty and, therefore, about 1,350kg
when full.
Ferrocement Grain Bin #3 (CS-1)
This  is the first of the new series of medium-size bins.  It is also a
vertical cylinder, having an inside diameter of 1.5 meters and an overall
height of 1.5 meters.  Because of their large size, these bins will
usually be kept outdoors or under open verandahs or corridors.  The roof
of this bin is dome-shaped so that rain water will run off.
Loading is done by a man standing on a stool.   A manhole of 450 mm diameter
with a detachable cover is provided in the roof, along with a padlocking
Unloading is done at the base through a screw conveyor identical to that
described under type CB-2.
The capacity of the bin is 3 cubic meters, and it will store 2-3 tons.  The
bin weighs 700kg when empty and 3,000kg when full.
Ferrocement Grain Bin #4 (CS-2)
The second bin in this series has the same inside diameter as type CS-1
viz 1.5 meters, but the overall height is increased to 2.9 metres.  The
construction of this bin is generally identical with type CS-1.  However,
because of the height the loading arrangement is different.  Provision
has been made for installing a pulley at the top manhole.  One man standing
on the roof of the bin will lift the sack by the pulley and empty that
sack into the bin.  A detachable ladder is provided for climbing up to
the roof.
Unloading arrangements provided at the bottom of the bin are identical
with Type CB-2.
The capacity of this bin is 5.4 cubic meters.   It will store 4.5 tons of
wheat.  The bin weighs about 1,100kg when empty and 5,600 when full.

51cp98.gif (353x353)

This manual has already discussed a number of materials used for storage --
mudblocks, plastic, metal, ferrocement.   The final construction material
discussed here is cement/concrete.
Three plans for storage structures which use cement are offered here.
The first, and simplest, was designed
by Peace Corps Volunteers in Senegal
and built by local farmers.

51cp99a.gif (353x353)


51cp99b.gif (600x600)

The second plan includes
detailed drawings for a
4.5 ton Cement Stave Silo.
This silo has been built and
tested by Peace Corps Volunteers
in Benin.  The testing
process has led to some design
improvements and these have
been incorporated into the
plan included here.
The third plan is for building and establishing Concrete Block Square
Silos for cooperative storage.
Since small farmers often cannot afford to make improvements by themselves,
they enter into cooperative agreements and store their grain
all together in large bins.  This plan offers a low-cost alternative to
the traditional large round silo, and the problems of keeping strict
measurements of each farmer's input to the silo, by giving information
on how to construct square, multi-celled (each cell is relatively small)

51cp100.gif (353x353)

                         BRICK GRAIN STORAGE SILO

51cp101.gif (353x353)

Traditional family granaries in West
Africa are constructed of clay, bamboo,
or millet stalks with a thatch roof.
They are easy prey for insects, rodents,
fire, and thieves. The silo described
here was designed by Peace Corps Volunteers
to protect grain against these
dangers and, equally as important, to
be of low cost and easy to build.
The silo is made of mortared concrete
bricks placed on a reinforced foundation.
A reinforced cover with a manhole
is cast to place over the bricks.   The
manhole cover can be made of sheet metal
for ease in handling, but if welding is
a problem, a cover can be cast in
All labor was done by Senegalese villagers with the help of a Peace Corps
Volunteer.  With the assistance of an experienced village mason, a farmer
can do the work necessary to build this silo.
       *   Protects against insects and rodents.
       *   Easy to build.
       *   Does not cost a lot of money.
       *   Holds 3-cubic meters of grain.
       *   Easy to reach to take grain in and out.
       *  Making the manhole cover may be difficult.
       *   Moisture may be a problem unless the silo is water-proofed.
Materials and Tools
       *   Cement (for bricks, foundation,
            cover, mortar, plaster)                   7 bags
       *   Reinforcing rod (6mm)                        36 meters
       *   Sheet metal for manhole cover                as needed.
1.  Make Forms for Silo Base and Cover
       *   Dig a hole 1.75m x 1.75m and 6cm deep.   This is for the
          silo base.
       *  Dig a hole 1.6m x 1.6m and 8cm deep.  This hole is for
          casting the silo cover.
       *   Make, and place in the hole, a wooden mold 60cm square
          by outside measurement.

51cp102a.gif (353x353)

2.  Make the Base and Cover
       *   Cut reinforcing rod for both the silo and base.
       *   Mix concrete and pour each form half full.
       *   Set reinforcing rods into concrete.
       *   Finish pouring concrete.
       *   Pour concrete for the cover up to a level of 8cm.  When
          concrete is somewhat set, make and place a form which is
          62cm square by 2cm high around the smaller form on top
          of the already poured concrete.  Then pour concrete into
          the space between the two frames.  This forms the lip
          around the manhole cover.  The manhole cover should be
          designed to fit around this lip.  This gives increased
          protection from insects and rodents.

51cp102b.gif (437x437)

       *   Remember to set
          the staples for
          the locking arrangement
          in the wet concrete
          of the silo cover.

51cp103a.gif (162x486)

       *   Make a manhole cover now if a concrete manhole cover is to
          be used.
       *   Keep the concrete damp.   Wet it 3 times a day and keep it shaded.
3.  Make Bricks
       *   Make 100 sandcrete bricks with a mixture of 1 to 5.
          The exact number of bricks needed depends upon the
          size of the brick.
       *   Dry and cure the bricks for 3 days.   Keep them damp
          so they dry slowly.
4.  Build the Walls

51cp103b.gif (317x317)

       *   Mortar the bricks into place with
          the corners overlapping alternately
          for strength.
       *   Let the bricks and mortar set for
          5 days.
       *   Plaster the inside.
5.  Put on the Silo Cover
       *   Put a layer of mortar on the top edge.
       *   Put the cover in place.
6.  Put on Manhole Cover
       *   Make a steel manhole lid and set it in place.   Or put
          in place an already prepared concrete cover.
       *   Lock the cover in place.

51cp103c.gif (162x486)

                     THE 4.5 TON CEMENT STAVE SILO
This silo was developed in Benin, West Africa, by local agricultural
extension agents and U.S. Peace Corps Volunteers.   Over 250 of these
silos have been built.  The plan in the following-pages is adapted from
one prepared by Peace Corps Volunteers.   The drawings were done for this
manual by Nicolas Reinhardt, a VITA Volunteer.
The cement stave silo, if protected from rain by a shelter, will keep
unwanted moisture away from the stored grain better than earthen-walled
silos which have not been specially treated.
In drier areas, the higher cost of the cement stave silo means that
farmers should check out other, cheaper types of silos.   However, the
cement stave silo will work in drier areas as well as more humid ones.

51cp104.gif (540x540)

     *   Stores large amounts of grain.
     *   Gives good insect control when insecticide is added to the grain
        to kill insects already in the grain.
     *   Offers good protection for the grain from rodents.
     *   Is less expensive than a metal silo of similar capacity
        and is more durable.
     *   Has to be protected from rain or it does not provide good
        moisture control.
     *   Uses materials and equipment which make it more expensive to build
        than the mudblock silo.
     *   Build the silo on high, well-drained ground.  Do not
        build the silo where it will be in the path of water
        from flooding or heavy rains.
     *   Test the ground to see if it will support the silo.
        You should build this silo on hard-pan, rock, or stable
      *  Dig a small hole, about 65cm deep.  If you do not reach
        hard-packed earth or rock, try another location, if
        possible.  If there is no other location available, and
        you are in doubt about whether the earth is hard enough,
        special precautions should be taken.
     *   Locate the silo so that it is level.   If a dryer
        such as the Pit Oil Barrel Dryer, is being built on
        the same site, the location must be chosen so that the
        front of the dryer is facing the oncoming winds during
        the time of year you will be drying.
A straw or tin-roofed shelter can be built before building the cement
stave silo.
     *   The shelter protects the silo from rain and sunlight.
        Also, it provides a good working place for the builders
        of the silo.
     *   It is important to build the shelter so that there is at
        least 50cm on all sides of the silo (and dryer).  This
        will ensure protection from rain.

51cp106.gif (437x437)

     *   The type of roof will depend on what the farmer can
        afford.   A thatch roof can always be replaced by a tin
        roof after the silo and shelter have had several years to
        pay for themselves.
     *   Many farmers build a larger shelter so that both the silo
        and a dryer, like an oil barrel dryer, can be put underneath
Tools and Materials
     *   Digging tools
     *   Tools for working cement and mortar
     *   Cement, 16 sacks (50kg each)
     *   Re-rod (6mm diameter), 10 - 12 bars (each 6m long)
     *   Galvanized wire (3mm diameter), 1 roll (4kg)
     *   Wire tighteners, 10
     *   Coal Tar, 15 litres
     *   Plastic or other suitable moisture barrier material
Some General Comments
     *   Cement should be stored on log supports or plastic:  it will
        harden if stored directly on the ground.  If there are lumps
        in the cement and they cannot be broken easily, they should
        be removed and the amount of cement should be increased by
        1/4 to 1/3.

51cp107.gif (540x540)

     *   Road sand can be used if it is clean and does not have too
        much clay content.
     *   Gravel should be smaller than 1/3 the thickness of the slab
        in which it will be used.  The gravel should be washed if
        there is dirt or other impurities in it.
     *   Water should be free of dirt, oil, and chemicals.  These
        weaken cement.  If water will be stored in barrels, these
        should be washed thoroughly before use.
     *   Mixing should be done on cement or on swept, packed earth.
        Be careful not to scrape dirt into the mixture.  When
        mixing on dirt, all mixtures should be made on the same
        spot since that spot will harden after the first mixing.
     *   Too much water causes cement to separate from the mixture
        when it is tamped.  Losing this cement weakens the mixture.
        20-25 liters of water for each 50kg sack of cement is about
        right for all mixes.
1.  Make the Forms for the Staves
     *   Make at least one wooden
        form (mold) for each of
        the two sizes of stave.
     *   Check the forms carefully
        to make sure they have
        very flat and regular inside

51cp108a.gif (600x600)

2.  Make the Staves
     *   Mix the mortar with a mixture of 1 part cement to 4 parts sand.
     *   Tamp the staves down firmly, with a bottle, for example.
        Be careful the cement is not so wet that water runs out
        of the form or the staves slump.
     *   Make 91 large staves and 26 small ones for the walls.
     *   Make 5 more large staves as extras in case of breakage.

51cp108b.gif (540x540)

     *   Make one large stave
        with a hole in it (12cm
        in diameter) for inserting
        the emptying plug.
     *   Place a ring of 6mm re-rod (50cm long) around the hole
        for added strength.
     *   Cure the staves.

51cp109.gif (600x600)

3.  Make Bricks for the Foundation
     *   Make a form of 14x20x30cm for making bricks.  This form
        will give the size blocks used in this particular
     *   Use a mixture of 1 part cement to 4-7 parts of sand,
        depending upon the quality of the sand and cement.
     *   Make about 80 bricks for a foundation like the four-brick
        layer foundation pictured below.  (The actual
        number of layers depends upon how far down you must
        dig to find hard-packed earth or rock upon which to
        build the foundation.)
     *   Make 8 more bricks, if you feel the earth is soft under
        the silo, or if you are not sure the floor slab is going
        to be made of very good quality cement.  These 8 bricks
        will make a pillar in the center of the foundation.
     *   Be sure to water and dry the bricks the same way as you
        did the staves.
     *   Substitute regular, already made concrete blocks of
        the type used in houses, if they are a good size to
        use and if they are strong.
4.  Build a Foundation
     *   Dig a hole with an outside diameter of 2.2m. The foundation
        should rest on hard-packed earth or rock.

51cp110.gif (600x600)

     *   Lay the bricks using a mortar consisting of 1 part cement
        to 6-8 parts sand.
     *   Lay the bricks so that each one crosses over a joint between
        bricks in the layer below. This will make the wall stronger.
     *   Be sure the foundation extends 15-20cm above ground level.
     *   Build the pillar, if required, by placing two bricks,
        joined with mortar, in the center of the foundation hole.
        Lay the second layer of bricks with mortar crosswise over
        the first layer.  Continue laying bricks and mortar until
        the pillar is even with the top of the foundation.
     *   Fill the foundation with sand and hard-pack (tamp) the sand to
        the level of the top layer of the foundation.
5.  Waterproof the base
     *   Use plastic sheets, coal tar, or tar felt.
     *   Lay a 3cm layer of mortar on top of the hard-packed
        sand if using coal tar or tar felt. This is not required
        when plastic is used.
     *   Overlap joints of tar felt 20cm and spread coal tar on
        the seams.
     *   Use 4 layers of coal tar if that material is chosen to paint
        over the 3 cm layer of mortar.
6.  Make a Form for the Floor Slab
     *   Use 29 large staves (temporarily) to make the form for the
        floor slab.
     *   Place the staves around the outside of the foundation wall
        in a 2.2m diameter circle.  In other words, the circle of
        staves will be flush with the outer perimeter of the foundation
     *   Hold the staves in place using two wires and wire tighteners.
     *   Line the inner face of the staves with paper, plastic, or
        masonite to prevent sticking when the staves are later

51cp111.gif (600x600)

     *   Mark the form to show a point 4cm above the base and
        another point 10cm above the base.  These marks will
        guide you when you pour the concrete into the form.
7.  Form the Re-rod Pattern for the Base
     *   Form a 6.6m re-rod perimeter for the slab.
     *   Use one 6m piece of 6mm re-rod and one 1m piece.
     *   Bend the ends of each re-rod piece to form 10cm hooks.
     *   Join these hooks together to make a longer bar for the
     *   Leave an extra 10cm at each end when cutting re-rods.
        These extra lengths will be bent to form hooks for attaching
        the straight bars to the perimeter re-rod.  The two
        longest straight re-rods are each 2.3m long.  A total of
        18 straight re-rod pieces will be needed.
     *   Put the re-rods into position.
     *   Attach all hooks and intersecting points with fine
     *   Place the finished re-rod pattern into the form to be sure
        it fits -- before you pour the cement.

51cp112.gif (285x437)

8.  Mix and Pour Concrete for the Floor Slab
     *   Use a mixture of one part cement, two parts sand, and three
        parts gravel (1:2:3).
     *   Mix the concrete so that it can be worked easily but does
        not flow.
     *   Wet the inside of the form completely before pouring the
     *   Pour 4cm of concrete before placing the re-rod pattern in.
     *   Tamp the concrete down well.
     *   Put the re-rod in and finish pouring concrete to the 10cm
        level marked previously.
     *   Tamp very well.   THIS IS IMPORTANT.
     *   Smooth and level the surface carefully.
     *   Water the slab 3 times per day for 7 days.  Keep the slab
9.  Mount the Wall

51cp113.gif (600x600)

     *   Mark a circle of 100cm radius from the center of the slab.
     *   Place 13 large and 13 small staves around the circle,
        alternating the large and small staves,with their smaller
        faces inside.
     *   Place a thin layer of 1:6 mortar under the bottom row of
        staves for proper seating.
     *   Place the large stave with the emptying hole in the first
        layer, with the hole toward the bottom slab.
     *   Place no mortar between the staves.
     *   Place and tighten a retaining wire at each 25cm of height.
     *   Place 2 wires in the bottom 25cm, 8cm from the top and the
        bottom of the small staves (one above and one below the
        emptying hole).
     *   Place the tighteners for these 2 wires only on the large
        staves.   When tightened, the tighteners should be centered
        on the large staves.
     *   Form each following layer by placing 13 large staves in
        the gaps until reaching a height of 2.0m (4 large staves
     *   Complete the final layer by placing 13 small staves in
        the remaining gaps.
     *   Hold these staves in place with 2 wires, 8cm from the top
        and 8cm from the bottom of the small staves.
10.  Make a Form for the Cover Slab
     The cover slab is like the floor slab except that it must have a
     filling hole and is only 8cm thick.
     *  Cover the top of the wall completely with solid boards.   These
        must extend beyond the edge of the wall.
     *   Place an upright collar of masonite on the boards 5cm outside
        the edge of the wall.
     *   Hold the collar in place with nails.
     *   Support the boards from within the silo if they are not
        strong enough to support a man without sagging.
     *   Cover the boards completely with paper or plastic inside
        the masonite circle to prevent the concrete from sticking
        to the boards or from leaking through any large cracks.
     *   Place the manhole (for entry and filling) form 20cm
        inside the masonite circle.  The form should be about a
        50cm diameter circle made with an inverted basket, or
        masonite held in place with nails.
11.  Form the Re-rod Pattern for the Cover
     *   Form the re-rod pattern in the same way as you did the floor
        slab except that space must be left for the manhole.

51cp115.gif (486x600)

     *   Test the pattern in the form for fit before pouring concrete.
12.  Make the Cover
     *   Mix another batch of 1:2:3 concrete for the cover.
     *   Pour and tamp a 4cm layer of concrete before placing
        the re-rod pattern.
     *   Place the re-rod pattern.
     *   Pour the remaining 4cm layer of concrete.
     *   Tamp and smooth out the slab with a slight slope away
        from the entry hole.
     *   Make a manhole cover 6cm thick and 60cm in diameter
        with the remaining concrete.
     *  Use a masonite strip or a hole dug in the ground and
        lined with paper as a form.
     *   Place a re-rod, bent into the correct shape for a
        handle, into the concrete.  This re-rod also gives added
        strength to the cover.

51cp116.gif (600x600)

     *   Cure and dry the cover slab and the manhole cover in the
        same way as the bottom slab.  (Wet the concrete 3 times a
        day for 7 days and keep the concrete shaded.)
     *   Be sure the slab is dry before removing the form (wait at
        least 10 days).  It is easiest to remove the boards by gently
        levering the edges of the slab, sliding out boards as you go.
     *   Be careful not to apply pressure to the strip between the manhole
        and the outer wall.  This strip is the weakest part of
        the slab.
     *   Close the space between the cover slab and the upper
        walls with mortar after taking out the boards of the form.
     *   Place a sealing ring cut from a rubber inner tube,
        for example, around the manhole. Or make a sealing
        ring of mortar.  If you use a piece of rubber, cover
        the rubber with mortar.  Cover the mortar with paper,
        and place the manhole cover on it.  This will provide
        a raised horizontal joint to prevent water from
        getting into the manhole.

51cp117a.gif (600x600)

13.  Make a Security Plate (Anti-Theft System)
     *   Use the bottom of an
        oil barrel or a piece of
        heavy sheet metal.
     *   Cut a piece 20cm x 25cm.
     *  Pierce two holes on one of
        the 20cm sides, 2cm in from
        the side and 4cm from each
        end.   A hinge will pass
        through each of these holes.
     *   Cut a slot 5cm long and 1.5cm
        wide, centered on the other
        20cm side of the metal piece,
        3cm from the edge.

51cp117b.gif (600x600)

     *   Use the remaining re-rod material to make a staple
        and two hinges.

51cp117c.gif (600x600)

14.  Plaster the Silo
     *   Make a 1:6-8 mortar mixture.
     *   Install the security plate before plastering the outside.
        Apply the mortar 2cm thick.

51cp118a.gif (600x600)

     *   Plaster the outside walls to a thickness of 2cm.
     *   Close the inside joints with a cement wash or plaster
        to keep grain from getting stuck in the joints and
        to increase moisture resistance.
     *   Put the plastic plug into place and use mortar to form a
        tight fit between the plug and emptying hole.  BE CAREFUL
        PULL IT OUT.

51cp118b.gif (600x600)

15.  Paint the Silo
     *   Let the silo dry after plastering for at least one month
        before using it.
     *   Do not apply coal tar to any plastered surfaces until after
        the plaster has been allowed to dry for at least two weeks.
*  Apply coal tar to the outside surfaces of the silo wall and
   to the cover slab to increase the silo's moisture resistance
*  Paint the inside floor with coal tar.  If the floor is
   painted, let it dry for at least two weeks before storing
   grain so that the grain does not stick to the tar.

51cp119.gif (600x600)

To be sure of good quality storage for your grain, it is important to
understand the proper way to use the Cement Stave Silo.   This can be
done easily by a few steps taken at the right times.
The Shelter
 The silo must have a good roof over it for protection from rain.
      *   Check the roof often to be sure there are no holes in it
         which will let rainwater fall on the silo.
      *   Repair holes immediately.
The Silo
      *   Make sure the filling and
         emptying holes are well
         sealed during storage times.
         Each time you add grain to
         the silo, carefully re-seal
         the filling hole.  Use
         cement mortar or banco
         (hand-packed, wetted earth).
         Banco is, of course, less
         expensive and is easier to
         use.   If the emptying hole
         does not seal tightly with
         mortar, it can be sealed with
         melted candle wax or banco.
<FIGURE 100>

51cp120.gif (600x600)

      *   Clean the inside of the silo and check for cracks in the walls
         shortly before the beginning of storage each year.  Light will
         pass through even the smallest cracks.  If cracks are found,
         cover them carefully with a mixture of cement and water.
      *   Use insecticides when storing grain in this silo.  Even though
         the silo is completely closed and insects cannot enter to attack
         the stored grain, there will always be some insects in the
         grain at the time of filling.  These insects not only destroy
         the grain by eating it, they can cause conditions which lead
         to rotting.
      *   Open the emptying hole each month to make sure the grain is
         storing well and that no insects are alive inside.  When you
         open the silo, if it seems very warm inside, or if there is
         a smell of rotting grain, empty the silo immediately.  Re-dry
         the grain.
                        CONCRETE BLOCK SQUARE SILOS
                         FOR COOPERATIVE STORAGE
Many farmers form cooperatives and store their grain collectively in
large bins.  This allows the farmer to get better quality storage (and
drying) than he could afford as an individual.
The formation of farmers' cooperatives is an important subject, but
this manual edition will not deal with coop formation and processes.
However, the following plan is presented as an illustration of how
newer ideas and methods of storage can be applied to cooperative
storage situations.  It is presented as an alternative to the larger,
round silos so often used for cooperative storage.
<FIGURE 101>

51cp121a.gif (486x486)

Some of the Advantages of the Square Silos
     *   Less expensive to build than groups of round silos because
        the walls are shared.  Also, building a group of round
        silos of the same capacity would take a greater area and
        would mean greater roofing costs.
     *   Easy to expand by adding more storage cells on to the
        ends and/or sides.
<FIGURE 102>

51cp121b.gif (218x437)

     *   Stress and pressure of the grain on the walls is not
        as great as in the round silo because each storage
        cell is relatively small.
     *   Only one cell has to be opened at a time to get out a
        farmer's grain.  This means that opening the bin is
        not going to mean that the grain in all the other bins
        must be re-fumigated, as would be needed if a large
        round silo had to be opened.
This multiple celled storage bin has a capacity of 30 tons.  It is
constructed of brick and re-inforced concrete with outside dimensions
of 9m x 4.6m.  It has 8 storage cells with inside dimensions of 2m x
2m x 2m.  A 4m x 4m open space for weighing and grain drying is
sheltered by the roof at one end. Each storage cell will have an opening
on the top to fill the silo and a chute at the bottom to remove grain.
<FIGURE 103>

51cp122.gif (243x486)

1.  Build the Walls
     *   Dig down to solid sub-soil.
     *   Pour a pad of re-inforced concrete 25cm thick x 25cm wide.
        This will extend under the inside and outside walls of the
        storage cells.
     *   Make wall bricks of fired clay brick or use concrete blocks.
     *   Make two layers of re-inforced concrete:  one, halfway up the
        walls and the other at the top of the walls.  These layers
        of concrete will support the stress of the stored grain
        and prevent bursting of the bin walls.
<FIGURE 104>

51cp123.gif (600x600)

2.  Make the Floor
     *   Fill and pack sand or coarse gravel in the bins to
        a height 20cm above ground level.  This layer of sand
        or gravel will reduce the amount of ground moisture
        which will be in contact with the floor slab.
     *   Lay a 7cm thick floor slab of re-inforced concrete on
        the hard-packed sand
     *   Put a layer of tar paper (or other waterproofing material)
        on the concrete floor slab.
     *   Coat all edges and seams of the tar paper with a heavy
        layer of roofing tar.
     *   Pour a final 3cm thick layer of concrete on top of the
        tar paper.  This will protect the tar paper moisture
        barrier from being damaged later during storage.  The
        final floor level is approximately 30cm above ground
3.  Finish the Walls
     *   Cover the walls with a rough cement plaster on both the
        inside and outside.
     *   Paint the outside walls with coal tar or other water-repellant
4.  Cover the Bins
     *   Make 8 individual slabs of reinforced concrete.
     *   Make the slabs on the ground using reusable wooden frames.
     *   Make a form which leaves a 60cm x 60cm opening for filling
        the bins.
     *   Place the re-inforced slabs side by side to cover the silo
     *   Join all edges and seams with a heavy layer of roofing tar.
     *   Fill with grain, put concrete cover over the filling hole and
        seal with roofing.
5.  Make a Roof
     *   Cover the entire building with a roof, for example, of
        corrugated sheet metal or local thatch.
6.  Dig a Drainage Ditch
     *   Dig a gutter along the sides of the building where the roof
        is pitched.
     *   Slope the ground away from the foundation.
The information in this manual is not and can not be complete.  The
information presented here cannot be immediately applicable or appropriate
to all regions or to every storage need.   You may well require
further technical assistance in adapting these materials and others
to your grain storage situation.   Some of that help can come from
books; much, from organizations and people.
The Tropical Products Institute (TPI) may already be a familiar name
to you.  This agency does a great deal to gather and distribute information
worldwide on grain and grain storage problems.   Materials from
the TPI library have been of great value in the preparation of this
Peace Corps and VITA are grateful to TPI for its permission to reprint
that agency's bibliography of materials on the various aspects of farm-level
grain storage.
             Tropical Products Institute
G64          Crop storage bibliography
             (with particular reference to
             the storage of durable
             agricultural produce in tropical
             and sub-tropical countries)
             Mrs. S.M. Blatchford and A.J. Wye
This bibliography has been produced by the Tropical Products Institute, a British
Government organization which helps developing countries to derive greater benefits
from their renewable resources.
Reproduction of this bibliography, in whole or in part, is gladly permitted provided that
full acknowledgement is given to the Tropical Products Institute, Foreign and
Commonwealth Office, (Overseas Development Administration), and to the authors.
Requests for further information on this subject should be addressed to:
Tropical Stored Products Centre
(Tropical Products Institute)
London Road
Slough SL3 7HL
This bibliography attempts to bring together a selection of the more important publications
dealing with tropical crop storage; it clearly cannot be exhaustive.
Where possible, the prices (at time of publication) and addresses are given for obtaining
publications listed here, excluding scientific papers.   A list of the most common addresses
appears below.
Sales Branch, 101-113, Pentonville Road, London, N.1.
Tolcarne Drive, Pinner, Middlesex.
Distribution & Sales Section, Via delle Terme di Caracalla, 00100 Rome, Italy.
Superintendent of Documents, U.S. Government Printing Office, Washington D.C. 20402, U.S.A
ANDERSON, J.A. and ALCOCK, A. W. (Eds).
1954            Storage of cereal grains and their products. St. Paul, Minn:   Amer. Ass.
                Cereal Chem., 1954, ix + 515 pp. (Out of print:   obtainable from Univ.
                Microfilms, Ann Arbor, Mich., price 10.00 [pound].   Currently under revision).
BUSVINE, J. R.  Insects and hygiene.  The biology and control of insect pests of medical
1966            and domestic importance. London:  Methuen and Co., 1966, 2nd rev.
                edn, xi + 467 pp. Price 5.00 [pound].
1969            Grain storage.  The role of fungi in quality loss.  Minneapolis, Minn.:
                Univ. Minnesota Press, 1969, vii + 153 pp. Price  6.50.
COTTON, R. T.   Pests of stored grain and grain products.  Minneapolis, Minn:  Burgess
1963            Publg Co., 1963, rev. edn, 2 + i + 318 pp. (Out of print).
MUNRO, J. W.    Pests of stored products.  London:   Hutchinson (The Rentokil Library),
1966            1966, 234 pp. Price 2.10 [pound].
1966            Storage of grain.  Moscow: Izdatel'stva 'Kolos', 1966, 3rd edn, 406 pp.
                (Translated into English by Keane, D.M. and edited by Kent, N.L. &
                Freeman, J.A. Boston Spa:  natn.  Lending Libr., 1969, 3 volumes, 244,
                287 & 307 pp.  Price 1.25 [pound] per vol., 3.75 [pound] the set).
              Quarterly.  Hapur:   Foodgrain Technologists' Research Association of
              India. Price $3.00 per annum.
              Quarterly.  Oxford:   Pergamon Press.   Price 12.00 [pound] per annum.
              Biannual.  Bulletin of the Tropical Stored Products Centre (Tropical
              Products Institute).  Free.   (Enquiries to the Tropical Stored Products
              Centre, (TPI), London Road, Slough SL3 7HL, Bucks).
Annual Reports
              Annual reports of the C.F.T.R.I., Mysore - 2, India. Priced.
              Reports of the infestation Control Laboratory (Ministry of Agriculture,
              Fisheries& Food). London:  HMSO.  Priced.
              Annual reports of the Nigerian Stored Products Research Institute, Federal
              Ministry of Trade. Lagos:  Fed. Minist. Inform., Printing Div. Priced.
              Annual reports of the Pest infestation Laboratory (Agricultural Research
              Council).  London:   HMSO. Priced.
              Annual reports (up to and including 1967) and then Biennial reports of the
              Tropical Products Institute, (Overseas Development Administration).   May
              be priced.  (Enquiries to the Scientific Secretariat, Tropical Products
              Institute, 56-62 Gray's Inn Road, London WC1X 8LU).
              1970.  Tropical Stored Products Centre.  A Report on the work 1965 - 1966.
              (The work of the Centre prior to 1965 was reported as part of the
              Annual Report 'Pest Infestation Research'; from July 1967 it forms a part
              of the Annual and Biennial Reports of the Tropical Products Institute.
              Enquiries to the Tropical Stored Products Centre, (TPI), London Road,
              Slough SL3 7HL, Bucks).
Handbooks, Bulletins, Special Reports
BROWN, W.B.     Fumigation with methyl bromide under gas-proof sheets.   Dep. Sci Ind.
1959            Res., Pest infest. Res. Bull. No. 1. London:  HMSO, 1959, 2nd edn, ii +
                44 pp. Price 22 1/2p.
1952            Insect infestation of stored food products in Nigeria.   (Report of a survey,
                1948 - 50, and of control measures adopted).  Colonial Res. Publn No. 12.
                London:  HMSO, 1952, 40 pp. Price 25p.
EASTER, S.S.    (Ed). Preservation of grains in storage.  Papers presented at the international
1947            meeting on infestation of foodstuffs, London, 5 - 12 Aug., 1947. Wash.,
                D.C.:  Fd. Agric. Org. agric. Stud. No. 2, 1948, 174 pp. Price $1.50.
FREEMAN, J.A.   Control of pests in stored agricultural products with special reference to
1958            grain.  Report of a survey in North and South America and certain Mediterranean
                countries in 1954 and 1955.  Org. eur. econ. Coop., eur. Productivity Agency
                Project No. 212, Feb. 1958. Paris:  OEEC, 1958, 169 pp. Price 57 1/2p.
                (OEEC Dist. & Sales Serv., 33 Rue de Franqueville, Paris 16e and overseas
FURMAN, D.L.    Suggested guide for the use of insecticides to control insects affecting crops,
1968            livestock, households, stored products, forests and forest products.  U.S.
                Dep. Agric., agric. Res. Serv., agric. Handbk No. 331, 1968, rev. edn, xvi +
                273 pp + 2 app. Price $1.50.
HALL, D.W.      Handling and storage of food grains in tropical and sub-tropical areas. FAO
1970            agric. Dev. Paper No. 90. Rome:  UNFAO, 1970, xiv + 350 pp.
                Price US $6 (2.40 [pound]).
1963            Common insect pests of stored food products.   A guide to their identification.
                Econ. Ser. Brit. Museum (nat. Hist.), No. 15. London:   British Museum,
                1963, 4th edn,, vi + 61 pp. Price 17 1/2p.
HOLMAN, L.E.    (Compiler).  Aeration of grain in commercial storages.  U.S. Dep. Agric.,
1960            Mktg Res. Rep. No. 170, 1960 (revised and reprinted Sept. 1966), 46 pp.
                Price 35 cts.
HUGHES, A.M.    The mites of stored food.  Tech. Bull. Minist. Agric. Fish, Fd, No. 9, 1961,
1961            vi + 287 pp. London:  HMSO. Price 87 1/2p.
ORGANISATION.   Report of the international conference on the protection of stored products,
1968            Lisbon 27 - 30 Nov. 1967.  EPPO Publications, Ser. A, No. 46-E.  Paris:
                EPPO, 1968,171 pp. Price 1.65 [pound].  (EPPO, 1 rue le Notre, Paris).
ORGANIZATION.   Report of the working party on Stored Products of Tropical Origin (Hamburg,
1969            5 - 6 Nov. 1968).  EPPO Publications, Ser. A, No. 51-E. Paris:  EPPO, 1969,
                38 pp + 7 tables.  Price 50p.   (EPPO, 1 rue le Notre, Paris).
ORGANISATION.   Report of the Working Party on Stored Products of Mediterranean Origin
1970            (Lisbon, 13 - 14 March, 1969).  EPPO Publications, Ser. A, No. 56.  Paris:
                EPPO, 1970, 85 + xxx pp. Price unknown.  (EPPO, 1 rue le Notre, Paris).
1968            The toxicity of contact insecticides to seed-infesting insects.   Series No. 6.
                Tests with bromophos on maize. S. Afr. Dep. Agric., tech. Serv., tech.
                Commun. No. 84. Pretoria:  Government Printer, 1968, 9 pp.
1958            Protection of stored seeds in Egypt. Bull. Minist. Agric. Egypt, Ext. Dep.,
                No. 295. Cairo:   General Organization for Government Printing Offices,
                1958, 16 pp.
LAHUE, D.W.     Evaluation of several formulations of malathion as a protectant of grain
1969            sorghum against insects - in small bins. U.S. Dep. Agric., agric. Res. Serv.,
                Mktg Res. Rep. No. 828, 1969, iv + 19 pp. Price 20 cts.
LAHUE, D.W.     Evaluation of malathion, diazinon, a silica aerogel and a diatomaceous
1970            earth as protectants on wheat against lesser grain borer attack ... in small
                bins.  U.S. Dep. Agric., agric. Res. Serv., Mktg Res. Rep. No. 860, 1970,
                iv + 12 pp.
LOCHNER, E.H.W. Safe storage of food grains in the Republic of South Africa. S. Afr. Dep
1963            Agric., tech. Serv., tech. Commun. No. 13. Pretoria:  Government Printer,
                1963, ii + 45 pp.
LOCHNER, E.H.W. Fumigation of maize in railway trucks in transit to the ports.  (In Africaans
1964            with English Summary).  S. Afr. Dep. Agric., tech. Serv., tech. Commun.
                No. 25. Pretoria:  Government Printer, 1964, ii + 62 pp.
1961            Prevention and control of infestation of stored grain by insect pests and
                rodents.  Prepared jointly by the Storage and Infestation, Division (Mktg
                Dept, Minist. Trade and Ind.) and Plant Protection Division (Minist. Agric.
                and Lands).  Kingston, Jamaica:   Govt Printer, 1961, iii + 57 pp.
MONRO, H.A.U.   Manual of fumigation for insect control. F.A.O. agric. Studies, No. 79.
1971            Rome: FAO, 1971, xii + 381 pp. Second edn, revised. Price 2.80 [pound].
ORDISH, G.      (Gen. Ed). Pest control in groundnuts.  PANS Manual No. 2. London:
1967            Minist. Overseas Dev., trop. Pestic. Res. H.Q. & Inf. Unit, 1967, iv + 138 pp.
                Price 45p. (56-62 Gray's Inn Rd, London, WC1 X 8 LU).
PREVETT, P.F.   An investigation into storage problems of rice in Sierra Leone.   Colonial
1959            Res. Studies, No.28. London:  HMSO, 1959, 52 pp.
RANSOM, W.H.    Buildings for the storage of crops in warm climates.   Dep. sci. ind. Res.
1960            Trop. Building Studies, No. 2. London:  HMSO, 1960, 24 pp. Price 22 1/2p.
SALMOND, K.F.   Investigations into grain storage problems in Nyasaland with special
1957            reference to maize (Zea mays L.). Colonial Res. Publn No. 21.   London:
                HMSO, 1957, 49 pp. Price 22 1/2p.
SMITH, C.V.     Meteorology and grain storage.   Tech. Note U.N. Wld met. Org., No. 101
1969            (WMO No. 243 TP 133).  Geneva:   Secretariat of World Meteorological
                Organisation, 1969, xvi + 47 pp. Price 1.00 [pound].
STEELE, B.      (Gen. Ed.).  Pest control in rice.   PANS Manual No. 3. London:   Minist.
1970            Overseas Dev. trop. Pestic. Res. H.Q. & Inf. Unit, 1970, ii + 270 pp.
                Price 62 1/2p. (56-62 Gray's Inn Rd, London WC1X 8LU).
1968            Improved storage and its contribution to world food supplies.   Chapter 4
                in 'State of Food and agriculture, 1968', pp 115 - 143. Rome:   FAO,
                1968, 205 pp. Price $5.75 or 2.30 [pound].
1969            Crop Storage.  Technical Report No. 1 of the Food Research and Development
                Unit, Accra, Ghana.  Prepared for the Government of Ghana by FAO
                acting as executing agency for the United Nations Development Programme,
                based on the work of J. Rawnsley.  PL:SF/GHA 7. Rome:  FAO, 1969,
                ix + 89 pp + 7 app.
1958            Stored grain pests. U.S. Dep. Agric. Fmrs Bull. No. 1260, 1958, rev.,
                46 pp. Price 25 cts.
WOGAN, G.N.     (Ed.).  Mycotoxins in foodstuffs.  Proceedings of a symposium at Massachusetts
1965            Inst. Technol., March 1964. Cambridge, Mass:  Mass. Inst. Technol.
                Press, 1965, xii + 291 pp. Price 3.75 [pound].
1970            Food storage manual.  (Prepared by the Tropical Stored Products Centre,
                Ministry of Overseas Development). Rome:   FAO, 1970, 3 vols, 820 pp.
                Price $18.
Advisory Leaflets
1969            C.M.I. descriptions of pathogenic fungi and bacteria.   Set 22, sheets 211 - 220.
                Kew:  Commonw. Mycol. Inst., 1969. Price 25p. (Commonw.
                Mycol. Inst., Ferry Lane, Kew, Surrey).
1967            Methods for sampling oilseeds. Br. Stand. No. 4146, 1967, 16 pp. Price 30p.
1968            Methods of test for cereals and pulses.  Part 2. Determination of moisture
                content of cereals and cereal products (basic reference method). Br. Stand.
                No. 4317, Part 2, 1968, 12 pp. Price 25p.
1968            Methods of test for cereals and pulses.  Part 4. Determination of impurities
                in pulses. Br. Stand. No. 4317, Part 4, 1968, 7 pp. Price 20p.
1969            Methods for sampling cereals (as grain).   Br. Stand. No. 4510, 1969, 19 pp.
                Price 50p.
1969            Methods for sampling pulses.  Br. Stand. No. 4511, 1969, 16 pp. Price 40p.
1969            Recommended common names for pesticides.   Br. Stand. No. 1831, 1969,
                4th rev., 107 pp. Price 2.00 [pound].
1968            Mechanical seed cleaning and handling. U.S. Dep. Agric., agric. Res. Serv.
                (in conj. w. Oregon agric. Exp. Stn), agric. Handbk No. 354, 1968, 56 pp.
                Price 55 cts.
1966            Fumigation with the liquid fumigants carbon tetrachloride, ethylene
                dichloride and ethylene dibromide.  Precautionary measures.  London:
                HMSO, 1966, rev. edn, i + 8 pp. Price 7 1/2p.
1968            Heating of grain in store.  Minist. Agric. Fish. Fd, Adv. Leafl. No. 404,
                1968, rev., 6 pp.  Single copies free.
1968            Insect pests in food stores.  Minist. Agric. Fish. Fd, Adv. Leafl. No. 483,
                1968, rev., 8 pp.  Single copies free.
1969            Fumigation with ethylene oxide.  Precautionary measures, 1969.  London:
                HMSO, 1969, 8 pp. Price 9p.
1969            Guide lines for mold control in high-moisture corn.  U.S. Dep. Agric., Fmrs
                Bull. No. 2238, 1969, rev., 16 pp. Price 10 cts.
1969            Controlling insects in farm-stored grain.   U.S. Dep. Agric., Leafl. No. 553,
                1969, 8 pp. Price 10 cts.
Scientific Papers
A full list of papers published by staff of the Tropical Stored Products Centre is available on
request from the TSPC, (TPI), London Road, Slough SL3 7HL, Bucks).
1957            Panorama actual dos problemas fitossanitarios dos produtos armazenados
                em Africa.  (Comprehensive survey of phytosanitary problems of stored
                products in Africa).  Garcia de Orta, 5 (4), 675 - 699.
ASHMAN, F.      The chemical control of stored food insect pests in Kenya. J. agric. vet.
1963            Chem., 4 (2), 44-48.
ASHMAN, F.      An assessment of the value of dilute dust insecticides for the protection of
1966            stored maize in Kenya. J. appl. Ecol., 3(1), 169 - 179.
ASHMAN, F.      Inspection methods for detecting insects in stored produce.   Trop. stored
1966            Prod. inf., (12), 481 - 494.
1969            An instrument for detecting insects within food grains.   Milling, 151 (3),
                32, 34 & 36.
ATTIA, R. and KAMEL, A. H.
1965            The fauna of stored products in U.A.R. Bull. Soc. ent. Egypte, 49, 221 - 232.
BAILEY, S.W.    Airtight storage of grain, its effects on insect pests. II. Calandra oryzae
1956            (small strain).  Aust. J. agric. Res., 7 (1), 7 - 19.
BAILEY, S.W.    Airtight storage of grain, its effects on insect pests. II. Calandra oryzae
1957            (large strain).  Aust. J. agric. Res., 8 (6), 595 - 603.
BAILEY, S. W.   The effects of percussion on insect pests of grain.   J. econ. Ent., 55 (3),
1962            301 - 305.
BAILEY, S. W.   Airtight storage of grain - its effect on insect pests. IV.   Rhyzopertha
1965            dominica (F.) and some other Coleoptera that infest stored grain.
                J. stored Prod. Res., 1 (1), 25 - 33.
BARNES, J. M.   Pesticide residues as hazards.  PANS, 15 (1), 2 - 8.
BREESE, M.H.    The infestibility of stored paddy by Sitophilus sasakii (Tak.) and
1960            Rhyzopertha dominica (F.).  Bull. ent. Res., 51 (3), 599 - 630.
BREESE, M.H.    Studies on the oviposition of Rhyzopertha dominica (F.) in rice and paddy.
1963            Bull. ent. Res., 53 (4), 621 - 637.
BURRELL, N.J.   The chilled storage of grain.  Ceres, (5), 15-20.
1960            Da occorrencia de algunas pragas de produtos ultramarinos en poroes de
                navios mercantes (Carreira da Guini).  (Occurrence and distribution of
                some pests of stored products in ships' holds of cargo ships of the Guinea
                Line).  Garcia de Orta, 8 (1), 47-57.
CASWELL, G.H.   The infestation of cowpeas in the Western Region of Nigeria.   Trop. Sci., 3
1961            (4), 154 - 158.
1960            Effect of moisture content on germination and growth of fumigated maize
                grain.  Emp. J. exp. Agric., 28, 139 - 149.
1965            Deterioration of stored grains by fungi.   A. Rev. Phytopath., 3, 69 - 84.
1963            Pathology of stored seeds.  Proc. int. Seed Test. Ass., 28, 701 - 711.
CLARKE, J.H.    Fungi in stored products.  Trop. stored Prod. Inf., (15), 3 - 14.
COAKER, T.H.    'Insack' treatment of maize with insecticide for protection against storage
1959            pests in Uganda.  E. Afr. agric. J., 24 (4), 244 - 250.
COLLINGS, H.    Hermetic sealing of a stack of maize with bituminous roofing felt.
1960            Trop. Agric., Trin., 37 (1), 53 - 60.
COURSEY, D.G.   Yam storage. I :  a review of yam storage practices and of information on
1967            storage losses.  J. stored Prod. Res., 2 (3), 229 - 244.
COVENEY, R.D.   Sacks for the storage of food grains.  Trop. stored Prod Inf.,(17), 3-22.
CRANHAM, J.E.   Insect infestation of stored raw cocoa in Ghana.   Bull. ent. Res., 51 (1),
1960            203 - 222.
1967            Moisture content/relative humidity equilibria of tropical stored produce.
                Part 3.  Legumes, spices and beverages.   Trop. stored Prod. Inf., (13), 15 - 34.
DAVIES, J.C.    Aluminium phosphide for bulk grain fumigation in Uganda.   E. Afr. agric.
1958            J., 24 (2), 103 - 105.
DAVIES, J.C.    A note on the control of bean pests in Uganda.  E. Afr. agric. J., 24 (3),
1959            174 - 178.
DAVIES, J.C.    Coleoptera associated with stored products in Uganda.   E. Afr. agric. J., 25
1960            (3), 199 - 201.
DAVIES, J.C.    Storage of maize in a prefabricated aluminium silo in tropical conditions.
1960            E. Afr. agric. J., 25 (4), 225 - 228.
DAVIES, J.C.    Experiments on the crib storage of maize in Uganda.   E. Afr. agric. J., 26
1960            (1), 71 - 75.
1969            Drying or anaerobically preserving small lots of grain for seed or food.
                Agron. J., 61 (6), 913 - 919.
ELDER, W.B.     CSIRO develops aeration system for farm-stored grain.   Pwr Fmg Bett. Fmg
1969            Dig., 78 (10), 10 - 13.
FULLERTON, R.L.  Low-cost farm buildings for storage and equipment housing in Ghana.
1968            Ghana J. agric. Sci., 1 (2), 165 - 170.
GILES, P.H.     The storage of cereals by farmers in Northern Nigeria.   Trop. Agric., Trin.,
1964            41 (3), 197 - 212.
GILES, P.H.     Control of insects infesting stored sorghum in Northern Nigeria.   J. stored
1965            Prod. Res., 1 (2), 145 - 158.
GILES, P.H.     Maize storage:  the problem of today.   Trop. stored Prod. Inf., (14), 9 - 19.
GILES, P.H.     Observations in Kenya on the flight activity of stored products insects,
1969            particularly Sitophilus zeamais Motsch.  J. stored Prod. Res., 4 (2); 317 - 329.
1966            Radiation disinfestation of grain and seeds.   Proc. Symp. Food Irradiation,
                Karlsruhe, 1966, pp 473 - 488.  Vienna :  Int. Atomic Energy Agency.
1968            Changes in the microfloral composition of moist sorghum stored under
                hermetic conditions.  Trop. Sci., 10 (2), 107 - 114.
GRAHAM, W.M.    Warehouse ecology studies of bagged maize in Kenya. I.   The distribution
1970            of adult Ephestia (Cadra) cautella (Walker) (Lepidoptera, Phycitidae).
                II.  Ecological observations of an infestation by E. cautella. III.  Distribution
                of the immature stages of E. cautella. IV.  Reinfestation following
                fumigation with methyl bromide gas.  J. stored Prod. Res., 6 (2):  I, 147 - 155;
                II, 157 - 167; III, 169 - 175; IV, 177 - 180.
GREEN, A.A.     The protection of dried sea-fish in South Arabia from infestation by
1967            Dermestes frischii Kug. (Coleoptera, Dermestidae).   J. stored Prod. Res.,
                2 (4), 331 - 350.
HALL, D.W.      Prevention of waste of agricultural produce during handling, storage and
1968            transportation.  Trop. stored Prod. Inf., (1 5), 15 - 23.
HALL, D.W.      Food storage in the developing countries.  J. R. Soc. Arts, 117 (5156),
1969            562 - 579.
HALLIDAY, D.    Build-up of free fatty acid in Northern Nigerian groundnuts.   Trop. Sci., 9
1967            (4), 211 - 237.
HAYWARD, L.A.W. Infestation control in stored groundnuts in Northern Nigeria.  Wld Crops,
1963            15 (2), 63 - 67.
HOWE, R.W.      Entomological problems of food storage in Northern Nigeria.   Bull. ent.
1952            Res., 43 (1), 111 - 144.
HOWE, R.W.      A summary of estimates of optimal and minimal conditions for population
1965            increase of some stored products insects.   J. stored Prod. Res., 1 (2), 177 - 184.
HOWE, R.W.      Losses caused by insects and mites in stored foods and feeding stuffs.  Nutr.
1965            Abstr. Rev., 35, 285 - 293.
1964            Some laboratory observations on the rates of development, mortality and
                oviposition of several Bruchidae breeding in stored pulses.  Bull. ent. Res.,
                55 (3), 437 - 477.
HYDE, M.B.      Hazards of storing high-moisture grain in airtight silos in tropical countries.
1969            Trop. stored Prod. Inf., (18), 9 - 12.
JOFFE, A.       Moisture migration in horizontally stored bulk maize:   influence of grain-infesting
1958            insects under South African conditions.  S. Afr. J. agric. Sci., 1
                (2), 175 - 193.
JOFFE, A.       The effect of physical disturbance or 'turning' of stored maize on the
1963            development of insect infestation. I. Grain elevator studies.   S. Afr. J.
                agric. Sci., 6, 55 - 64.
1959            Storage and preservation of fatty foods.  Food Sci., Mysore, 8, 257 - 262.
KHALIFA, A.     On open-air and underground storage in the Sudan.  Bull. Soc. ent. Egypte,
1960            53 (44), 129 - 142.
KHALIFA, A.     The relative susceptibility of some varieties of sorghum to Trogoderma
1962            attack.  Emp. J. exp. Agric., 30 (118), 133 - 136.
KOCKUM, S.      Protection of cob maize stored in cribs.   E. Afr. agric. J., 19 (2), 69 - 173.
KOCKUM, S.      Control of insects attacking maize on the cob in crib stores.   E. Afr. agric.
1958            J., 23 (4), 275 - 279.
1954            Experiments in the use of insecticides for the protection of grains in storage.
                Bull. ent. Res., 45 (2), 295 - 311.
McFARLANE, J.A. An annotated record of Coleoptera, Lepidoptera, Hemiptera and Hymenoptera
1963            associated with stored produce in Jamaica.   Trop. Agric., Trin., 40 (3), 211-216
McFARLANE, J.A. The productivity and rate of development of Sitophilus oryzae (L.) (Coleoptera,
1968            Curculionidae) in various parts of Kenya.   J. stored Prod. Res., 4 (1), 31 - 51.
McFARLANE, J.A. Stored products insect control in Kenya.  Trop. stored Prod. Inf., (18), 13 - 23
McFARLANE, J.A. Treatment of large grain stores in Kenya with dichlorvos slow-release strips
1970            for the control of Cadra cautella.  J. econ. Ent., 63 (1), 288 - 292.
MACKAY, P.J.    Theory of moisture in stored produce.  Trop. stored Prod. Inf., (13)., 9 - 14.
1964            Toxicity of calcium phosphate to some pests of stored grain.   Nature,
                Lond., 202 (4939), 1359 - 1360.
1961            Pre-harvest prophylaxis for infestation control in stored food grains.
                Nature, Lond., 192 (4800), 375 - 376.
1959            Insecticidal effects of activated charcoal and clays.   Nature, Lond, 184
                (4693), 1165 - 1166.
1963            Some aspects of the problem of bulk storage of foodgrains in India.
                Wld Rev. Pest Control, 2 (2), 25 - 35.
1969            Fungi associated with Sorghum vulgare under different storage conditions
                in India.  PANS, 15 (3), 365 - 367.
1963            Fumigation of insects.  A. Rev. Ent., 8, 239 - 264.
PARKIN, E.A.   The protection of stored seeds from insects and rodents.   Proc. Int. Seed
1963            Test. Ass., 28 (4), 893 - 909.
PARKIN, E.A.    The onset of insecticide resistance among field populations of stored product
1965            insects.  J. stored Prod. Res., 1 (1) 3 - 8.
1957            Effect of insect infestation on stored grain:   II.  Studies on husked, hand-pounded,
                milled raw rice and parboiled milled rice.   J. Sci. Fd Agric., 8 (9),
                512 - 516.
1954            Effect of insect infestation on stored wheat.   I.  Studies on soft wheat.
                J. Sci. Fd Agric., 5 (1), 51 - 54.
PIXTON, S.W.    Moisture content - its significance and measurement in stored products.
1967            J. stored Prod. Res., 3 (1), 35 - 47.
PIXTON, S.W.    A possible rapid method of determining the moisture content of high-moisture
1970            grain.  J. Sci. Fd Agric., 21 (9), 465 - 467.
POINTEL, J-G.   Contribution a la conservation du niebi, du vouandzou, du mais, des
1968            arachides et du sorgho.  (Contribution to the preservation of cowpeas,
                Voandzeia subterranea (Bambarra groundnut), maize, groundnuts and
                sorghum).  Agron. trop., Nogent, 23 (9), 982 - 986.
POINTEL, J-G.      Essai et enquete sur greniers a mais togolais.   (A trial and survey on
1969               Togolese maize granaries).  Agron. trop., Nogent, 24 (8), 709 - 718.
1965               Pusa bin for grain storage.  Indian Fmg, 15 (1), 14 - 16.
PREVETT, P.F.      A study of rice storage under tropical conditions.   J. agric. Engng Res., 4
1959               (3), 243 - 254.
PREVETT, P.F.      The distribution of insects in stacks of bagged groundnuts in Northern
1964               Nigeria. Bull. ent. Res., 54 (4), 689 - 713.
1970               Irradiation of early instars of the Angoumois Grain Moth.  J. econ. Ent.,
                   63 (4), 1241 - 1247.
RHYNEHART, T.      The control of insects infesting groundnuts after harvest in the Gambia:
1960               IV.  The practical application of control measures.  Trop. Sci., 2 (3), 134 - 139.
ROBERTSON, J. V.   Trials with small capacity grain silos in Dar es Salaam, Tanzania.   E. Afr.
1968               agric. for J., 34 (2), 263 - 276.
ROWLANDS, D.G.     The metabolism of contact insecticides in stored grains.   Residue Rev., 17,
1967               105 - 177.
1965               Storage structures for large scale handling and preservation of food grain.
                   Bull. Grain Tech., 3 (2), 62 - 69.
1968               Protection of marketable grain.  Bull. Grain Tech., 6 (1), 16 - 20.
1965               Studies on the large scale storage of food grains in India.   Part II.  Studies
                   on the relative suitability of cement concrete and aluminium bins for
                   storing wheat.  Bull. Grain Tech., 3 (4), 135 - 141.
1967               Studies on the large scale storage of food grains in India.   Part III.  Studies
                   on the insect and temperature fluctuations in bag storage of wheat.   Bull.
                   Grain Tech., 5 (1), 3 - 11.
SODERSTROM, E.L.  Effectiveness of green electroluminescent lamps for attracting stored-product
1970               insects.  J. econ. Ent., 63 (3), 726 - 731.
SOUTHGATE, B.J.   Plastics films for the bulk storage of food.   Plast. Inst. Trans. & J., 33
1965               (103), 11 - 15.
1960               Germination of cereal, sorghum and small legume seeds after fumigation
                   with hydrogen phosphide.  J. econ. Ent., 53 (1), 1 - 4.
1961               Effect of methyl bromide and hydrocyanic acid fumigation on the germination
                   of corn seed.  J. econ. Ent., 54 (8), 764 - 770.
SWAINE, G.         Trials on the underground storage of maize of high moisture content in
1957               Tanganyika.  Bull. ent. Res., 48 (2), 397 - 406.
1260               Effect of insect infestation on stored field bean (Dolichos lablab) and
                   black gram (Phaseolus mungo).  Fd Sci., Mysore, 9, 79 - 82.
1958               Effect of insect infestation on stored grain:   III.  Studies on Kaffir corn
                   (Sorghum vulgare).  J. Sci. Fd Agric., 9 (12), 837 - 839.
WATTERS, F.L.    Effects of grain moisture content on residual toxicity and repellency of
1959               malathion.  J. econ. Ent., 52 (1), 131 - 134.
WATTERS, F.L.    Physical methods of insect control.  Proc. Ent. Soc. Manitoba, 21,
1965               18 - 27.
WATTERS, F.L.    An appraisal of gamma irradiation for insect control in cereal foods.
1968               Manitoba Ent., 2, 37-45.
1970               Polythene sacks for the control of insects in grain.   J. stored Prod. Res.,
                   6 (1), 97 - 101.
WRIGHT, F.N.       New storage, transportation and handling techniques for tropical agricultural
1965               produce.  Congr. Prot. Cult. trop., Marseilles, 1965, pp 93 - 98.  Marseilles:
                   Chambre de Commerce et d'Industrie.
1962               The potential uses of plastics for storage with particular reference to rural
                   Africa.  Trop. Sci., 4 (2), 74 - 81.
                              Conversion Tables
                       Simple methods are given here for
                     converting English and metric units
                     of measurement.  Following these is
                     a series of useful conversion tables
                     for units of area, volume, weight,
                     pressure and power.
  The chart in Figure 3 is useful
for quick conversion from meters and
centimeters to feet and inches, or
vice versa.  For more accurate results
and for distances greater than 3 meters,
use either the tables in Figure 2 or
the equations.
  The chart in Figure 3 has metric divisions
of one centimeter to three meters,
and English units in inches and feet
to ten feet.  It is accurate to about
plus or minus one centimeter.
  An example will explain how to use
the tables.  Suppose you wish to find
how many inches are equal to 66cm:   On
the "Centimeters into Inches" table look
down the leftmost column to 60cm and then
right to the column headed 6cm.   This
gives the result, 25.984 inches.
  1 inch   = 2.54cm
  1 foot   = 30.48cm
          = 0.3048m
  1 yard   = 91.44cm
          = 0.9144m
  1 mile   = 1.607km
           = 5280 feet
  1cm      = 0.3937 inches
  1m       = 39.37 inches
          = 3.28 feet
  1km      = 0.62137 miles
          = 1000 meters
                            Inches into centimeters                         FIGURE 2
                             (1 in. = 2.539977 cm.)
inches    0        1       2       3        4       5       6        7       8       9
  0       cm.     2.54    5.08     7.62   10.16   12.70    15.24   17.78   20.32    22.86
 10      25.40   27.94   30.48    33.02   35.56   38.10    40.64   43.18   45.72    48.26
 20      50.80   53.34   55.88    58.42   60.96   63.50    66.04   68.58   71.12    73.66
 30      76.20   78.74   81.28    93.82   86.36   88.90    91.44   93.98   96.52    99.06
 40     101.60  104.14  106.68   109.22  111.76  114.30  116.84  119.38  121.92   124.46
 50     127.00  129.54  132.08   134.62  137.16  139.70   142.24  144.78  147.32   149.86
 60     152.40  154.94  157.48   160.02  162.56  165.10   167.64  170.18  172.72   175.26
 70     177.80  180.34  182.88   185.42  187.96  190.50   193.04  195.58  198.12   200.66
 80     203.20  205.74  208.28   210.82  213.36  215.90   218.44  220.98  223.52   226.06
 90     228.60  231.14  233.68   236.22  238.76  241.30   243.84  246.38  248.92   251.46
                            Centimeters into inches
                              (1 cm. = 0.3937 in.)
cm.    0        1       2       3        4       5       6        7       8       9
 0    inches   0.394   0.787    1.181   1.575   1.969    2.362   2.756   3.150    3.543
10    3.937    4.331   4.724   5.118    5.512   5.906   6.299    6.693   7.087   7.480
20    7.874    8.268   8.661   9.055    9.449   9.843  10.236   10.630  11.024  11.417
30   11.811   12.205  12.598  12.992   13.386  13.780  14.173   14.567  14.961  15.354
40   15.748   16.142  16.535  16.929  17.323  17.717  18.110   18.504  18.898  19.291
50   19.685   20.079  20.472  20.866   21.260  21.654  22.047   22.441  22.835  23.228
60   23.622   24.016  24.409  24.803   25.197  25.591  25.984   26.378  26.772  27.165
70   27.559   27.953  28.346  28.740   29.134  29.528  29.921   30.315  30.709  31.102
80   31.496   31.890  32.283  32.677   33.071  33.465  33.858   34.252  34.646  35.039
90   35.433   35.827  36.220  36.614   37.008  37.402  37.795   38.189  38.583  38.976
<FIGURE 105>

51cp143.gif (600x600)

  The chart in Figure 5 converts pounds
and ounces to kilograms and grams or
vice versa.  For weights greater than
ten pounds, or more accurate results,
use the tables (Figure 4) or conversion
equations.  See "Length Conversion,"
Figure 2, for an example of the use of
the tables.
  On the chart, notice that there are
sixteen divisions for each pound to
represent ounces.  There are 100 divisions
only in the first kilogram, and
each division represents ten grams.
The chart is accurate to about plus
or minus twenty grams.
  1 ounce = 28.35 grams
  1 pound = 0.4536 kilograms
  1 gram   = 0.03527 ounce
  1 gram   = 2.205 pounds
FIGURE 4                    Kilograms into pounds
                            (1 kg. = 2.20463 lb.)
kg.    0        1       2       3        4       5       6        7       8       9  
 0      lb.    2.20    4.41     6.61    8.82   11.02    13.23   15.43   17.64    19.84
10   22.05    24.25   26.46   28.66    30.86   33.07   35.27    37.48   39.68   41.89
20   44.09    46.30   48.50   50.71    52.91   55.12   57.32    59.53   61.73   63.93
30   66.14    68.34   70.55   72.75    74.96   77.16   79.37    81.57   83.78   85.98
40   88.19    90.39   92.59   94.80    97.00   99.21  101.41   103.62  106.82  108.03
50  110.23   112.44  114.64  116.85   119.05  121.25  123.46   125.66  127.87  130.07
60  132.28   134.48  136.69  138.89   141.10  143.30  145.51   147.71  149.91  152.12
70  154.32   156.53  158.73  160.94   163.14  165.35  167.55   169.76  171.96  174.17
80  176.37   178.58  180.78  182.98   185.19  197.39  189.60   191.80  194.01  196.21
90  198.42   200.62  202.83  205.03   207.24  209.44  211.64   213.85  216.05  218.26
                            Pounds into kilograms
                            (1 lb. = 0.45359 kg.)
lb.    0        1       2       3       4        5       6       7        8       9
 0      kg.    0.454   0.907    1.361   1.814   2.268    2.722   3.175   3.629    4.082
10    4.536    4.990   5.443   5.897    6.350   6.804   7.257    7.711   8.165   8.618
20    9.072    9.525   9.979  10.433   10.886  11.340  11.793   12.247  12.701  13.154
30   13.608   14.061  14.515  14.969   15.422  15.876  16.329   16.783  17.237  17.690
40   18.144   18.597  19.051  19.504   19.958  20.412  20.865   21.319  21.772  22.226
50   22.680   23.133  23.587  24.040   24.494  24.948  25.401   25.855  26.308  26.762
60   27.216   27.669  28.123  28.576   29.030  29.484  29.937   30.391  30.844  31.298
70   31.751   32.205  32.659  33.112   33.566  34.019  34.473   34.927  35.380  35.834
80   36.287   36.741  37.195  37.648   38.102  38.555  39.009   39.463  39.916  40.370
90   40.823   41.277  41.730  42.184   42.638  43.091  43.545   43.998  44.452  44.906
  The chart in Figure 1 is useful for
quick conversion from degrees Celsius
(Centigrade) to degrees Fahrenheit and
vice versa.  Although the chart is fast
and handy, you must use the equations
below if your answer must be accurate
to within one degree.
Degrees Celsius = 5/9 x  Degrees
  Fahrenheit -32)
Degrees Fahrenheit = 1.8 x (Degrees
  Celsius) +32
  This example may help to clarify the
use of the equations; 72F equals how
many degrees Celsius?
  72F = 5/9 (Degrees F -32)
  72F = 5/9 (72 -32)
  72F = 5/9 (40)
  72F = 22.2C
  Notice that the chart reads 22C, an
error of about 0.2C.
                             Conversion Tables
Units of Area
1 Square Mile        = 640 Acres                    = 2.5899 Square Kilometers
1 Square Kilometer   = 1,000,000 Square Meters      = 0.3861 Square Mile
1 Acre               = 43,560 Square Feet
1 Square Foot        = 144 Square Inches            = 0.0929 Square Meter
1 Square Inch        = 6.452 Square Centimeters
1 Square Meter       = 10.764 Square Feet
1 Square Centimeter  = 0.155 Square Inch
Units of Volume
1.0 Cubic Foot       = 1728 Cubic Inches            = 7.48 U.S. Gallons
1.0 British Imperial Gallon = 1.2 U.S. Gallons
1.0 Cubic Meter      = 35.314 Cubic Feet            = 264.2 U.S. Gallons
1.0 Liter            = 1000 Cubic Centimeters       = 0.2642 U.S. Gallons
Units of Weight
1.0 Metric Ton       = 1000 Kilograms               = 2204.6 Pounds
1.0 Kilogram         = 1000 Grams                   = 2.2046 Pounds
1.0 Short Ton        = 2000 Pounds
                             Conversion Tables
Units of Pressure
1.0 Pound per square inch             = 144 Pounds per square foot
1.0 Pound per square inch             = 27.7 Inches of Water(*)
1.0 Pound per square inch             = 2.31 Feet of Water(*)
1.0 Pound per square inch             = 2.042 Inches of Mercury(*)
1.0 Atmosphere                        = 14.7 Pounds per square inch (PSI)
1.0 Atmosphere                        = 33.95 Feet of Water
1.0 Foot of Water = 0.433 PSI         = 62.355 Pounds per square foot
1.0 Kilogram per square centimeter    = 14.223 Pounds per square inch
1.0 Pound per square inch             = 0.0703 Kilogram per square centimeter
(*) at 62 degrees Fahrenheit (16.6 degrees Celsius)
Units of Power
1.0 Horsepower (English)              = 746 Watts = 0.746 Kilowatt (KW)
1.0 Horsepower (English)              = 550 Foot Pounds per second
1.0 Horsepower (English)              = 33,000 Foot Pounds per minute
1.0 Kilowatt (KW) = 1000  Watts      = 1.34 Horsepower (HP) English
1.0 Horsepower (English)              = 1.0139 Metric Horsepower (cheval-vapeur)
1.0 Metric Horsepower                 = 75 Meters X Kilogram/Second
1.0 Metric Horsepower                 = 0.736 Kilowatt = 736 Watts