TECHNICAL PAPER #50
UNDERSTANDING CEREAL CROPS I
WHEAT, OATS, BARLEY, AND RYE
Roy M. Stephen & Betsey Eisendrath
Dr. Glen M. Wood
Dr. Dennis Sharma
1600 Wilson Boulevard, Suite 500
Arlington, Virginia 22209 USA
Tel: 703/276-1800 . Fax: 703/243-1865
Understanding Cereal Crops
I: Wheat, Oats, Barley, & Rye
[C]1986, Volunteers in Technical Assistance
This paper is one of a series published by Volunteers in
Assistance to provide an introduction to specific
technologies of interest to people in developing countries.
The papers are intended to be used as guidelines to help
people choose technologies that are suitable to their
They are not intended to provide construction or
details. People are urged to contact VITA or a similar
for further information and technical assistance if they
find that a particular technology seems to meet their needs.
The papers in the series were written, reviewed, and
almost entirely by VITA Volunteer technical experts on a
voluntary basis. Some 500 volunteers were involved in the
of the first 100 titles issued, contributing approximately
5,000 hours of their time. VITA staff included Suzanne
handling typesetting and layout, and Margaret Crouch as
and project manager.
VITA Volunteer Roy Stephen is a professor of agronomy at
Land College in Mattoon, Illinois. Betsy Eisendrath is a
writer and editor who frequently helps VITA on projects such
as this. Dr. Glen
Wood is an agronomist and professor of plant
and soil science at the University of Vermont.
agronomist Dr. Dennis Sharma is a technical adviser to both
private sector and government institutions through his
International Agricultural Consulting Services.
David Ray has
many years of farming experience, with emphasis on rice,
and soybeans. Mr.
Stephen was assisted by Lisa Nichols.
Medernach, and Sharon Spray, students at Lake Land College.
VITA is a private, nonprofit organization that supports
working on technical problems in developing countries. VITA
information and assistance aimed at helping individuals and
groups to select and implement technologies appropriate to
situations. VITA maintains an international Inquiry Service,
specialized documentation center, and a computerized roster
volunteer technical consultants; manages long-term field
and publishes a variety of technical manuals and papers.
UNDERSTANDING CEREAL CROPS I
Wheat, Oats, Barley and Rye
by VITA Volunteers Roy M. Stephen and
Cereal crops, or grains, include a wide variety of plants
are members of the grass family (Gramineae) grown for their
seeds or kernels, which are used primarily for food. Grains
rich in carbohydrates and contain substantial amounts of
as well as some fat and vitamins.
They are the staple food for
most of the world's population.
Over 70 percent of the world's
harvested area is planted to grains, for an output of a
and a half tons a year.
All grains consist of the same three basic parts: (1) the
endosperm or starchy interior of the seed, the food source
the developing seedling; (2) the germ or embryo; and (3)
Most grains can be grown under a variety of weather and soil
conditions, and most are cultivated in a number of different
(speaking very generally), oats and rye are
most often grown in cool climates with less fertile soils,
wheat and barley in mild climates with better soils. Maize
preferred in warm temperate and subtropical areas. In moist
tropical areas, rice is predominant; in drier tropical
sorghum and millets.
These eight are the most widely cultivated
grains. Less common
grains, having limited production, include
wild rice and Job's tears.
There are also several plants, like
flax, buckwheat, and amaranths, that are often mistakenly
to as grains, but are not members of the grass family.
This paper focuses on production and use of wheat, oats,
"Understanding Cereal Crops II" covers maize, sorghum,
rice, and millet.
It is not known exactly how long ago people began to eat
grains, but 75,000-year-old implements have been found that
have been used for milling them.
Grains were among the first
plants to be domesticated.
This discovery lies at the source of
recorded history, for it was the cultivation of grains that
it possible for human beings to end their constant
search of food. With
the cultivation of grains, they could
settle together in communities.
By 3000 B.C. they were growing
all the major grains we raise today.
Many of today's varieties of these grains, however, are
varieties that have been developed at places like the
Rice Research Institute (IRRI) in the Philippines and the
International Maize and Wheat Improvement Center (CIMMYT,
its name in Spanish) in Mexico.
Researchers at centers like
these work to develop strains that will produce higher
lodge(*) less, tiller more, resist diseases and pests, and
improved nutritional value.
In combination with improved agricultural techniques, these
have produced dramatic increases in yields.
But there are
achieve the full yields of which they are capable,
they often require irrigation and increased inputs of
as well as of pesticides and herbicides in some cases.
These create further pressures on already strained water and
resources, as well as a need for larger capital investment.
Moreover, a new variety of grain seldom remains under
for more than three to five years before new strains of
and pests develop to which the variety is susceptible.
ADVANTAGES AND DISADVANTAGES OF GRAIN CROPS
Grain crops have the following advantages:
There is a grain crop, and often more than
one, suited to
climate or soil.
They give farmers the highest yield per unit
of land of
They can be grown using manual labor, but
farming, which makes them significantly
labor-intensive and less expensive to produce.
They are easy to handle and compact to
Under good storage conditions, they can be
kept for a
They are rich in starch and calories. and
protein, as well as some fat and
- - - - - - - - - - - - - - - -
tendency of the grain stem to fall over under the
weight of the seed head. Tiller: capable of producing more
one shoot from the root of the plant.
The disadvantages of grain crops include the following:
1. They are more
vulnerable to damage from pests and diseases
2. They must be
dried thoroughly before storing, and cannot
be stored in a
3. Their protein
does not supply all essential amino acids.
It must be
supplemented with protein from other sources.
MAJOR USES OF GRAINS
Grains as Food
Grains supply over 65 percent of the calories that people
worldwide. In parts of the world where most of the grain
used as human food, they supply an even higher
percent in the Far East and Southeast Asia, and over 70
in Africa and the Middle East.
People consume grains in a variety of forms: whole, in
and soups, dried, and ground into flour that is used to make
and leavened breads, noodle products, and cakes and cookies.
People eat syrups and oils extracted from grains, and drink
and other beverages brewed from them.
The outer hull of most grains is indigestible and must be
before the grain can be eaten. Often the grain is milled
to remove the germ and the inner layers of the endosperm's
improves the keeping qualities of the grain and
makes it more uniform in appearance, but results in major
in its nutritional value.
Grains as Feed
When grain is used as animal feed, it is consumed in the
seeds themselves, and as pasturage, hay, and silage.
animals consume about the same amount of the grain crop as
do, but if current trends continue the animals will soon be
consuming the greater proportion.
Feeding grain to animals being raised for meat is an
use of the crop. It
takes, for example, 4 kilograms of grain to
produce 1 kilogram of pork, and between 7 and 8 kilograms of
grain to produce 1 kilogram of beef.
Nonfood Uses of Grains
The nonfood uses of grains are much less important than the
uses. Hulls are used
as fuel and mulch, and straw is used as a
packing, thatching, and bedding material.
Grains are used
industrially in the manufacture of soaps, solvents,
plastics, and paper.
II. MAJOR GRAIN CROPS
This section summarizes the cultivation requirements and
uses of four major grains--wheat, oats, barley, and rye.
detailed information for specific grains on specific sites
obtained from local agricultural extension services,
and research stations.
More hectares of land worldwide are devoted to wheat than
other crop. Wheat
has been cultivated since before recorded
history. It probably
originated in western Asia; it was being
grown along the Nile by 5000 B.C., in China by 3000 B.C.,
imported in Greek and Roman times.
Today the chief producing
countries are the Soviet Union, United States, China, India,
France, and Canada.
There are thousands of varieties of wheat. Three important
are common or bread wheat (Triticum vulgare or T. aestivum),
club wheat (Triticum compactum), and durum wheat (Triticum
Wheat may be classified as hard or soft.
Hard wheats, generally
grown in the more arid wheat-producing regions, have higher
protein content than soft wheats.
Most of this protein is in
the form of gluten.
Hard wheat produces what are called strong
flours have granular texture, with small, hard
grains of starch and a high proportion of gluten.
absorb large quantities of water, and are particularly
is a kind of hard wheat used mainly to make
Soft wheats (further subdivided into red and
white wheats) usually grow where rainfall is plentiful.
made from soft wheat has larger, softer grains than flour
hard wheat. It
contains a lower proportion of gluten and can
absorb relatively little water.
This limits its suitability for
bread-making. Is is
often called pastry flour, and is used
mainly for making cakes and cookies.
Most of the wheat produced
in Australia and Western Europe is soft wheat; elsewhere,
wheat is predominant.
The main wheat-producing regions of the world lie in the
Wheat is adaptable to a wide range of growing
conditions, but is best suited to cool climates with
weather is especially important during the
tillering and early growth stages.
In tropical countries, wheat
is usually grown at high altitudes, but it can be grown in
warmer areas if the humidity is low.
Wheat needs 25 to 100 centimeters of rainfall a year in the
cooler climates where it is most common; in hot areas, it
50 to 175 centimeters.
It can be grown under irrigation
where the rainfall is insufficient.
Prolonged drought without
irrigation reduces yields. Relatively dry areas produce
higher quality than humid or irrigated areas do, but yields
dry areas are substantially smaller. Rusts and other
that attack wheat flourish in hot, humid areas.
Wheat can be grown on a wide range of soils, but does best
well-drained, fertile soils of medium to heavy texture. Silt
clay loams usually give the best yields, but wheat also does
well on fine sandy loams and clay soils. Very heavy or very
soils should be avoided.
Bread wheats can be divided into two groups, winter wheats
spring wheats, depending on how they are cultivated.
wheats are planted in the fall for harvest the following
They cannot be cultivated where winters are too severe, but
they can survive winter, they produce a larger yield than
wheats are grown in most of the world's major
Spring wheats are grown where the winters
are too severe for winter wheats; they also do better than
wheats in warm climates. Spring wheats are usually sown in
in the northern hemisphere, for harvest in the autumn.
a shorter growing season than do winter wheats, but require
least 90 days, so they should be planted as early as the
Wheat may be grown alone or mixed or in rotation, often with
Methods of cultivation vary according to the
type of wheat and to climate and soil conditions.
The ground is
thoroughly cultivated, either by hand or by machine. The
should be well-pulverized but compact.
If beds for irrigation
are to be used, they are made just before sowing, fertilizer
often broadcast, and a presowing irrigation is performed.
The rate of seeding varies between 22 and 135 kilograms per
(the larger amounts are used where moisture is plentiful.
Seed may be broadcast by hand, but this can result in fairly
germination, wasted seed, and an irregular plant stand.
seeding in rows can alleviate these problems and produce
yields. The seed is
usually deposited in a moist seedbed and
covered with 2.5-7.5 centimeters of packed soil, deeper only
the climate is very dry.
Wheat takes up most nutrients from the soil before it
continues to take up nitrogen until the grain is ripe. It
responds to fertilizers. Applications of nitrogen range from
34 to 135 kilograms per hectare. Heavier amounts are applied
regions where there is more moisture in the soil.
fertilizer can reduce yields by causing plants to lodge and
delaying maturity so the crop becomes more subject to damage
rusts. Semidwarf wheats can take up larger amounts of
without lodging, enabling them to produce larger yields.
is usually applied at 34 to 56 kilograms per hectare,
in humid regions; potassium, at 23 to 56 kilograms per
hectare. Manure and
compost may be used, and green manuring is
Spring wheats can mature in as little as three months, more
quickly than winter wheats, which usually grow five to six
in the tropics, and often longer elsewhere.
Wheat is usually
harvested with a sickle, or mechanically with a combine,
grain is completely ripe and the straw is brittle and
The moisture content of the grain must be 13 percent or
it is higher, the grain needs to be dried before it can be
The average yield for wheat worldwide is about 1,600
per hectare, but the range is enormous, and far higher
have been obtained with hybrid cultivars on intensively
As long as it is kept clean, cool, dry (no more than 12-13
moisture), and free from insects, wheat can be stored almost
this reason, wheat is often stockpiled for
distribution during famines.
Diseases and Pests
Wheat is subject to many diseases and insect pests. Wheats
to some diseases and pests have been developed, but no wheat
variety is resistant to all.
Black stem rust (Puccinia graminis) is one of the worst and
common diseases. Its spores are carried on barberry plants
the wind. Much of the infection can be avoided by early
Wheat is also susceptible to several smuts; crop rotation
clean seed are used against them. The poisonous fungus ergot
sometimes attacks wheat, but is less common in wheat than in
The most common insect pests include grasshoppers, which are
sometimes sprayed from airplanes, and Hessian fly (Mayetiola
destructor), which can be limited by timing the planting of
wheat to avoid the main brood of insects.
The wheat stem sawfly
(Cephus cinctus) is another insect enemy of wheat.
Wheat seeds are ground into flour for human
is an important ingredient in many breads, biscuits,
cakes, dumplings, noodles, breakfast foods, and beer.
wheat makes good forage for livestock, and by-products of
are widely used as animal feed.
There are also nonfood uses.
Wheat straw is used as a mulch, and as a weaving and
industry, wheat is an ingredient in emulsifiers,
adhesives, and polishes.
Wheats vary in their protein content, but hard wheats
16 percent, and soft wheats 8-10 percent. The protein is
in lysine, one of the essential amino acids. The wheat germ
and bran are high in niacin, thiamine, riboflavin, and
as well as phosphorus and iron. However, the more refined
flour is, the more of these nutrients are lost. A highly
flour may contain about one ninth of the niacin. a fifth of
thiamine, and a quarter of the riboflavin that the original,
wholegrain flour contained.
Some flours are enriched to restore
some of the lost nutrients.
Considerable research effort has gone into developing
a hybrid of wheat and rye. It is somewhat higher in protein
content than wheat, and can be grown in places where wheat
not do well. However, its yields have been undependable, and
protein is low in gluten. These and other drawbacks have not
totally overcome and triticale is still not very widely
About 50 million tons of oats are grown worldwide each year.
Avena sativa is the most common species. (Oats are relative
latecomers to the domesticated cereals, since they were
not raised until around 2500 B.C., with cultivation
North Africa, the Near East, and the temperate parts of
Oats are widely grown in temperate zones, especially in
America, the Soviet-Union, and northern Europe. Outside
areas, there is considerable production in China, Argentina,
Australia, and Algeria. Oats are fairly new to tropical
and not very important there. In such areas, they are grown
mainly at high altitudes during the cool season.
While oats are generally tolerant of a wider range of
soils, and agricultural techniques than are most other
winter types of oats are actually less hardy than rye,
barley. Oats are best suited to cool, moist climates, but
also be grown under irrigation. Hot dry weather causes
oat grains to wither or fill poorly. Heat damage can be
to some extent by selecting early varieties, particularly of
oats (Avena byzantina), or better yet some of the
hybrids that have been developed. Oats can do well on a
of soils. They grow best on rich, friable loams, especially
and clay loams, that are well drained. Oats are often grown
rotation. In cooler regions, maize is the crop that most
Oat culture is fairly simple.
First the land is usually plowed
and harrowed, sometimes more than once.
Then the seed is sown
broadcast or drilled in rows.
Most often, it is sown broadcast
when the crop is for fodder, and drilled in rows 23 to 30
apart when it is for grain.
The seed rate averages 90
kilograms per hectare, less when the oats are broadcast in
regions or are a companion crop for legumes.
Like wheat, oats can be divided into winter and spring
depending on when they are planted.
In the northern hemisphere,
oats are usually sown sometime between October and December,
almost any month of the year oats are being sown somewhere
world. When they are
a spring crop, they are planted as soon as
the weather is warm enough for the land to be worked.
must be done before the average temperature reaches
The fertilizer requirements for oats are similar to those
wheat. Nitrogen is
the most important element, but applications
of more than 34 to 67 kilograms per hectare are likely to
lodging. Often, for
a grain crop, this is avoided by applying
the manure or chemical fertilizer to the crop preceding the
in the rotation.
Nitrogen may be applied directly to the fodder
crop at the rate of 38 to 45 kilograms per hectare.
cultivars that can accept heavy fertilization without
lodging have been developed.
Oats also respond well to phosphorus,
and often to potassium, in humid areas.
Oats are not usually intercultivated.
If they are being grown
under irrigation, they receive three or four irrigations. If
are being grown for fodder, they are usually cut between one
three times, and then the plants are allowed to set seed.
Oats planted in the spring are usually ready for harvest in
three months. Winter
crops take longer to mature: if the oats
are sown in October, the grain will ripen in April.
harvesting lowers yields of both grain and straw, but
too late increases losses of grain through shattering.
usually yield 10.75 to 21.5 quintals per acre of grain.
Diseases and Pests
The main diseases that attack oats are smut and rust. Smut
prevented by seed treatment. There is no remedy for rust,
hybrids resistant to the disease have been developed.
disease that damages oats is Septoria, which is most likely
develop during rainy or humid weather; chemicals are used to
combat it. The greatest insect threats come from the spring
aphids, the chinch bug, and the armyworm.
Oats are used mainly as animal feed. The young leaves are
nutritious and high in protein. They can be pastured or cut
hay before maturity. The grain can be fed by itself or as
mixtures. The straw is used as an emergency feed and as
bedding. Oats are often fed whole to horses and sheep; for
they are usually ground or chopped.
Human beings consume oats mostly in the form of oatmeal made
rolled oats. Their protein does not make oats suitable for
but they can be used in cookies and cakes. The oat grain
is quite high in fat and protein. Its usual protein content
12-13 percent, but Avena sterilis with a protein content as
as 30 percent has been bred experimentally. Oats are a very
source of vitamin B1. They contain an appreciable amount of
vitamin E and the same amount of riboflavin as other grains,
much less niacin than wheat.
Oats are put to a number of uses in industry, one of the
important of which is for the manufacture of furfural, a
used solvent made from oat hulls.
Certain soil and climate conditions may cause growing oat
to contain high enough levels of nitrates to be poisonous to
livestock. Ample applications of phosphate may help prevent
The symptoms of nitrate poisoning include rapid breathing
blueing of the mucous membranes; death occurs from
The remedy is an early intravenous injection of methylene
at a dose of 4 milligrams of methylene blue per pound of
weight in a 4 percent solution with distilled water.
There are a number of species of barley, the most common of
is Hordeum vulgare. (Barley was one of the earliest cereals
domesticated, probably originally in the Near East. It was
as a food for people and animals in China around 2800 B.C.
Stone Age Europe). Barley was the most important grain for
in Europe until around the 16th century, when it was
gradually replaced by wheat and rye. Today, the Soviet Union
by far the biggest producer, followed by France, Canada, and
United Kingdom. Important producers outside Europe and North
America include Turkey, India, Morocco, and Korea.
Barley does best in temperate regions where the climate is
but it can adapt better than any other cereal to extremes of
as well as to salinity, drought, and summer frost. It is
cultivated farther north than any other cereal, to the edges
the Arctic, and at altitudes of 4,572 meters in the
Winter types, however, are less cold hardy than rye and
does best when the growing season is 90 days or more but can
reach maturity in as little as two to three months. It is
to other grains in its ability to withstand dry heat; it
does very well on the desert margins where rainfall is very
limited, as in North Africa, where it is the most important
Barley is most often grown on light soils, but it does best
well-drained, even-textured loams of fair fertility. Barley
a more porous soil than wheat does, and can tolerate
better. It is unsuited to acid soils with a pH below 6;
cause aluminum toxicity, which retards root growth. (This
can be corrected with calcium applications.)
Barley can be grown unirrigated in areas where there is
38 and 51 centimeters of rainfall.
Where the climate is drier,
irrigation is needed.
Yields for barley range between 1,120 and 2,240 kilograms
hectare depending upon variety, soil, and climate.
Like wheat and oats, barley can be divided into spring and
types. Spring barleys can be planted farther north than any
grain. In warmer climates, barley is usually sown in fall or
winter. In the northern hemisphere, the best time for
usually between the middle of October and the middle of
Barley is most commonly planted in rotations; it is also
companion crop with grasses and small-seeded clovers.
seedbed should be well prepared, though cultivation for
usually less thorough than for wheat.
Nevertheless, the best
yields of barley come from soil that is well tilled and
completely free of weeds.
Three or four plowings with a wooden
plow or one plowing with an improved iron plow, followed by
harrowing, should be adequate.
Unlike wheat, barley needs a
seedbed that is slightly loose.
The seed may be broadcast, or drilled in rows 15 to 23
apart. It should be
sown about 4 centimeters deep in
humid areas, and deeper where the soil is drier.
seeding rate ranges from 54 to 135 kilograms per hectare,
the smaller quantities in drier regions.
Intercultivation is not normally practiced with barley
soil is very weedy.
If this is the case, then it is useful to
hand-weed and hoe once.
An irrigated crop needs two or three
irrigations; generally speaking, barley needs less water
Barley usually responds well to an application of 28 to 56
of nitrogen per hectare, the larger quantities going on
moist soils. An
excess of nitrogen can cause lodging and lower
the malting quality of the grain. On some soils, the barley
is not fertilized directly, but draws on nutrients in the
compost, or commercial fertilizer that was applied to the
crop in the rotation.
Barley is usually harvested when fully ripe, that is, when a
made in the kernel with a thumbnail stays visible for some
The crop can be harvested by hand or by machine.
the early morning can sometimes help reduce losses from
is often dried in windrows to reduce the
moisture of the grain, which should be 14 percent, or
12 percent, for safe storage.
It should be stored under
Diseases and Pests
Barley is subject to many of the same diseases and pests
attack wheat. These include rusts, stripe, scab, and rot. It
susceptible to the parasitic fungi of the Helminthosporium
and to several smuts. Barley seeds can be chemically treated
against scab, smut, or stripe, but the most effective
to grow disease-resistant varieties.
A number of approaches are used to limit infestation of
infestation can be reduced by using a crop
rotation that includes species not subject to attack (such
clover, soybeans, flax, or buckwheat). Time of planting can
a role in controlling Hessian flies, which live no more than
days, and aphids.
Chinch bugs can be trapped as they migrate,
and induced with lures to lay their eggs where they can be
destroyed. Chemical treatment can also be used.
The main uses of barley are to make malt and to feed
most important use of barley for human consumption is for
used primarily in brewing beer, but also in the manufacture
breakfast food and confections.
Malt is prepared by soaking and
Since only unbroken grains will germinate,
care in the threshing and handling of barley is particularly
important. High protein content is not desirable in a barley
grown for malt. Otherwise, barley in human food is eaten primarily
in the form of pearl barley, which is barley that has been
dehulled and mechanically polished in the same way that oats
sometimes are. Barley is a staple food grain in parts of
North Africa, where it is eaten as a porridge or flatbread.
Because of its low gluten content, barley flour cannot
Because of its hull, barley contains 5 percent less
material than maize does, and its feeding value for animals
considered to be 95 percent that of maize; compared to
barley contains about the same percentage of carbohydrates,
little more protein, and a little less fat. Barley is
particularly well suited to fattening cattle and hogs.
usually ground or rolled before being fed to any animal except
sheep. Its straw is
of a soft type that can be used as a bulk
roughage feed or as animal bedding.
Rye (Secale cereale) was probably first grown in the eastern
Mediterranean area or in western Asia.
It was the last of the
cereal crops to come under cultivation, and even now is the
The principal rye-growing areas are the
Soviet Union, eastern and central Europe, the United States,
Turkey, and Canada. Production is declining because of
preference for wheat, and because of wheat's higher yields.
Rye is grown primarily for grain, but sometimes for
hay, and as a cover crop.
It is an annual, but it sometimes
tends to maintain itself as a perennial by sprouting from
stubble. It is grown primarily in temperate and cool
regions. The ability of spring rye to withstand cold is
than that of any other grain except barley, which may equal
It can be grown as far north as the Arctic Circle, and at
of up to 4,270 meters.
It is also grown in warmer areas,
but production there is much less than where it is colder.
Rye grows quite dependably on poor soils, and can produce
on soils considered too poor for wheat. It responds well to
fertile land and good care, but usually the better soils are
reserved for other crops, and the poorer, sandier soils are
to plant rye. Rye benefits from fertilizers, especially
up to 134 kilograms per hectare can be applied. Too much
will promote lodging in rye grown for grain, but a spring
dressing of nitrogen may be used where the rye is being
Rye is grown in much the same way as other small
wheat, it can be grown as a winter crop or a spring crop;
rye is most common.
Winter rye is sown at about the same time
that winter wheat is sown, but the timing is not as
with rye, because it is more resistant to cold than wheat
Winter rye can be sown almost any time during the late
early fall for harvest the following summer; early seeding
produces the most fall pasture.
Spring rye should be planted as
early as possible. Rye can be grown continuously or in
Rye for pasture or green manure is often grown in mixtures
The land may be disked or plowed.
Rye is sown broadcast or
drilled. Sometimes it is drilled directly into small-grain
without preparing the soil; this is satisfactory if the land
is fairly free from weeds.
Rye is seeded at between 63 and 125
kilograms per hectare.
The lower rates are commonly used when
the rye is being grown for grain, the higher rates when it
be pastured or used to suppress weeds.
Rye ripens the earliest of the small grains; it is usually
about a week before winter wheat. It has the tallest and
straw of the small grains, which makes harvesting difficult.
The average yield worldwide is 1,560 kilograms per hectare.
Diseases and Pests
Rye suffers less from most diseases than any of the other
crops. Its only
serious enemy is the parasitic fungus ergot
The fungus penetrates the developing
kernel and produces a large purplish mass that contains
highly poisonous substances.
Rye is the richest in carbohydrates of all the cereal crops,
contains less fat than wheat. Its vitamin B1 content is a
lower than that of barley and wheat, and much lower than
oats. Rye flour can be used for bread-making, but pro-duces
compact, heavy loaf compared to a loaf made from wheat
this reason, rye flour is usually mixed with wheat flour for
bread-making. Rye is also used to make alcoholic beverages.
The most important use of rye is for animal feed. Its leaves
high in vitamin A. It is grazed and fed as hay. Since rye
are sticky to chew and not very palatable, they are usually
ground and fed to animals in mixture with other grains. Rye
seldom makes up more than a third of the mixture.
Rye is often used as a cover crop to prevent soil erosion,
a smother crop to limit weeds.
It is sometimes plowed under be
fore flowering, for use as green manure.
Its straw, which is
tough for animal feed, is used as a packing material, and to
thatching and matting.
III. QUESTIONS TO ASK BEFORE PLANTING A GRAIN CROP
The overview presented above is intended to give the reader
sense of the requirements of the various grain crops. Before
to raise any grain in an area where it is not presently
grown there are a number of preliminary questions that
guidance should be obtained from local agricultural
Some of the questions to be considered are:
Is the climate suitable for this crop?
Are the type of soil and its pH and salinity
are they suitable for this crop?
Are fertilizers available to meet the crop's
and potassium needs?
Can the crop's moisture needs be met through
water? If not, is enough water
irrigation? Does the cost of
irrigation compare favorably
benefits the crop will yield? Is the
equipment available? Is the terrain suitable?
Have sources of supply been found for seeds,
herbicides, equipment, and anything else that
may be needed
for growing this crop?
Is enough capital available to purchase the
Is the farmer able to invest the time and
to grow the
Has the information been gathered about the
are available? Has a choice been made about
to be planted?
What kind of erosion control, if any, will
if this crop
is planted? Are the resources for
If part of the harvest is to be kept for
later use, are
facilities available that can keep the grain
and safe from pests?
Is there a market for the grain products?
"Barley," "Corn," "Food,"
"Grain," "Oats," and "Rye."
"Cereals and Other Starch Products."
The New Encyclopedia
"Food" and "Wheat."
Colliers Encyclopedia. (1984).
Everyman's Encyclopaedia. (1978).
Hanson, Borlaug, and Anderson.
Wheat in the Third World.
Colorado: Westview Press, 1982.
Hubbell, Donald S.
Tropical Agriculture: An Abridged Field
Kansas City, Missouri: Howard W. Sams
Kahn, E.J., Jr.
"The Staffs of Life: The Golden Thread." The
New Yorker, June
18, 1984, pp. 46-88. (about corn)
Kahn. E.J., Jr.
"The Staffs Of Life: Fiat
Panis." The New
17, 1984, pp. 57-106. (about wheat)
Kassam, A.H. Crops
of the West African Semi-arid Tropics.
India: International Crops Research
for the Institute
for the Semi-arid Tropics, 1976.
Martin, Leonard, and Stamp.
Principles of Field Crop Production.
Macmillan Press, 1986.
Poehlman, John M.
Breeding Field Crops. Westport, Connecticut:
Schery, Robert W.
Plants for Man. 2nd edition.
Jersey: Prentice-Hall, Inc., 1972.
Uichanco, Leopoldo B., editor.
Philippine Agriculture. College
University of the Philippines, 1959.
Vickery, Margaret L. and Vickery, Brian.
Plant Products of
The Macmillan Press Ltd., 1979.