CHAPTER XIII PLANTAIN CASE STUDY: POST-HARVEST OPERATIONS

1.1 Economic and social impact of the crop

1.2 World trade

1.3 Primary product

1.5 Requirements for export and quality assurance

1. Introduction

Post-harvest systems differ fundamentally depending on whether commodity is meant either for consumption in its production area, or for export at international or intercontinental levels. Procedures are linked to various factors:

- Fragility of the product;

- Importance of the relative values granted to quality criteria;

- Existence of recommended and established norms;

- Eating habits;

- Utilisation of sub-products of the commodity;

- Consumer revenues;

- Cultural data.

The evaluation of the system after harvest should consider the type of market.

In the export channels meant to supply remote markets (such as plantain export circuits from Central America to the United States or from Africa to Europe), the product is subjected to the specifications and taste preferences of importers:

- Calibre of fruits;

- Cleanliness;

- Identification of the origin of the commodity;

- Packaging in cartons.

The selling price of the packed and dispatched plantain is meant to encourage producers and exporters to maintain or even improve the quality of their products.

Goods appreciate in price according to its presentation in packaging (packaging is the first criteria that can be observed) and agronomic characteristics. When the product does not adhere to export norms, it is put aside and often enters the local commercial channel.

The different actors of the traditional channel grant a relative and secondary importance to the packaging of the commodity. The most important point here is availability of the product for consumption. The post-harvest system does not place much importance on the state of the product.

Cooked banana plantains are food crops, in Africa mainly consumed in their production areas.

The typical observer often thinks that the rough handling of the crop creates the important losses of the harvest. Logically this would indicate scant availability of this food for consumers with a corresponding drop in revenues of the sellers.

The traditional channel is old using local practices. Actions intended to improve this situation have been confronted with problems. Custom and habit block application of methods used in the international export of dessert bananas.

The evaluation of losses after harvest in traditional channel based on the criteria of international export of banana often leads to exaggeration of the issue.

Despite the importance of plantain and the socio-economic role it plays, post-harvest practices are somewhat identical from country to the country, from continent to continent.

The most recent survey shows that after harvest, physical losses are limited (Kuperminc, 1985; Lendres, 1990 ; N'da Adopo, 1992 and 1993) to scarcely over 5 percent.

Several factors explain this situation:

- Production areas are either locales with great demand, or are not far from them. The product arrives at the market before being unfit for consumption;

- Plantain is consumed at all stages of ripeness. Even those eliminated as a result of rough handling are collected and used. The declassified fruit that is no longer purchased by a category of consumers is sold to poorer people. Beside the standard distribution professionals, there are auxiliary sellers who introduce damaged fruits in a sub-market: Hence everything is eventually recovered;

- There is no excess of plantains when compared with actual eating needs. Plantain is part of food crop production (See Tables 1);

- The producer manages the clusters for his own consumption and does not harvest important quantities of plantains if he thinks that he will not be able to sell them;

- The means used by the intermediary for the acquisition of clusters from the producer and their transport to the consumption market prevents him from accepting the loss of this commodity.

Post-harvest loss of the plantain is generally restricted to the decrease of the commercial value as compared to expected gains.

Table 1. Per capita consumption of the main food crops in Côte d'Ivoire from 1985 to 1990 (kg)

Year	Rice	Maize	Other cereals	Gnam	Cassava	Plantain	Cocoyam	Groundnut	Wheat
1985	57,8	28,7	2,4	118,2	97,2	67,7	8,2	7,0	3,7
1986	58,4	28,6	2,4	115,6	96,8	68,3	8,0	7,0	3,8
1987	59,0	28,5	2,4	113,0	96,4	68,8	7,9	7,1	3,8
1988	59,6	28,4	2,3	110,4	96,0	69,4	7,7	7,1	3,9
1989	60,2	28,2	2,3	108,0	95,6	69,9	7,6	7,2	3,9
1990	60,8	28,1	2,2	105,6	95,2	70,4	7,4	7,2	4,0

(Source: Food crops consumption estimates, July 1987, Statistical office, Ministry of Rural Development

The most obvious losses occur in field. The reasons for this are:

- There is no one available to buy non-harvested clusters;

- Loss of potential production due to decrease in yields, destruction of banana trees by hurricanes, parasites, pests and poor soil. (See Figures 1 and 2). These losses increase with the age of the plantain and can be significant (See Tables 2, 3 and 5).

Figure 1: Percentage of some food crops losses in fields in 8 subdivisions of Fako zone, South - west District of Cameroon (TLU, IRA-Ekona, 1987)

Figure 2: Average percentages of field losses of some food crops in Fako zone (Cameroon)(TLU, IRA-Ekona, 1987)

Table 2: Estimated losses of plantain plants based on age of the plantation (agricultural sector of Kunda Southwest Cameroon)

Cropping cycle	Parasites and wind	Mechanical destruction
1	2 - 5	Accident
2	10 - 25	_ 2%
3	20 - 50

Table 3: Estimated percentages of seasonal distribution of plant decreases caused by hurricanes, compared to all damaged plants (Kumba Zone, Southwest Cameroon)

DRY SEASON	WET SEASON
November - March	April - May June - October
5 % maximum	20 % 95 % 80 %

The channel should be viewed as a global design where methods are balanced with eating habits, the means and tradition. (See Figures 3 and 4).

Figure 3: Regions producing bananas plantain in the world and in Africa

Figure 4: Summary of operations in banana export trade

At the farm level, men (often husbands) manage the commercialisation of the plantain in the field while the product is abundant.

Women are more numerous than men in the distribution circuit. If wholesalers are the sector where men are most represented (more than 50 percent), retail sale of the clusters and fingers is largely dominated by women (more than 95 percent of retailers in Africa).

Mainly adults participate in the distribution of the crop. One often encounters in markets, sedentary retailers more than fifty or 16 years old maximum (See Figures 5a-c). Activities require many trips to visit farms for many days to collect the product, negotiate with carriers, which are accomplished by the most young and vigorous age group. Typical handlers are young men (See Figure 6).

Figure 5a+b+c:
Commercialization takes place in the lorry during unloading

Figure 6:
Harvesting bananas for modern trades (export). One handler to cut with a machete and the other to receive the bunch carefully (Simmonds, 1959)

1.1 Economic and social impact of the crop

The classification of banana trees is based on the hypothesis that all edible bananas come from two parents, two species of the Musa type: Musa acuminata (AA) and Musa balbisiana (BB). These two fertile species crossed in the wild state. Letters A and B designate the ploid and composition of gene in these parents (Simmonds, 1959; De Langhe, 1976; Rowe, 1976). The absence of meiose at the level of female gametes caused the formation of AAA, AAB, ABB triploids and even tetraploids (See Figure 7) (Champion, 1976).

Figure 7: Schematic way indicating origin of bananas and plantains,
by Champion (Fruits, Vol. 31, no 9, 1976)

True plantains are triploids AAB, and divide themselves into French plantain and Horn plantain. Within these two types, there are a great many varieties (cultivars) grown. The French plantain cluster possesses a persistent male axis, whereas that of type Horn is absent or degenerates quickly after flowering. Several clones of these plantains differentiate themselves mainly by the number of hands, the size of the fruit and the cluster. It is possible to find small, medium, giant French, false and true Horns (See Figure 8). In broad terms, plantain refers to all cooking bananas (ABB).

Figure 8: The 3 major types of plantain bunches
(source: Fruits, Vol. 38, no 6, 1983)

False Horn and true Horn are found extensively in Côte d'Ivoire (at least 90 to 95 percent of the production). The French species comprise 50 percent of plantains in Cameroon. Rwanda and Burundi are important producers of cooking bananas and of cultivars used for preparing local traditional «beers» called beer bananas.

Table 4: Characteristics of some plantain and cooking bananas

Groups	Name allocated	Length of cycle (forest zone)	Size	Sensitivity to wind	Sensitivity to the black stripes diseases	Drops out	Number of hands per clusters	Productivity	Utilisation
Great French	Essong, Ovang, Zue, Ekon	15 to 18 months	big	very sensitive	sensitive	weak	8 to more than 10	very good	fried, boiled
Medium French	French sombre, French Claire, Elat	12 to 15 months	medium	sensitive	sensitive	good	6 to 8	good	fried, boiled
Dwarf French	Njockkon	18 months	small	a little sensitive	sensitive	very weak	8 to more than 10	good	fried, boiled
False Horn	Big Ebanga, Bâtard, Ebang, Mbouroukou	less or equal to 12 months	medium	sensitive	sensitive	good	4 to 7	medium	roasted, pounded
True Horn	One (two or three) hand plantain	12 months	medium to large	sensitive	sensitive	medium	1 to 3	weak	fried, boiled
Other cooking bananas	Pelipita, Assubu, Baro Baro, Bluggoe Fongamou, Cacambou Popoulou	12 to 5 months	medium	a little sensitive	good resistance to sensitive	good	6 to more than 10	good	fried, boiled (as plantain)
Hybrids to cook	FHIA 1 FHIA 3	14 months 12 months	medium medium	great resistance great resistance	good resistance a little sensitive	medium good	9 8 to 9	good very good	fried, fried

(Source: Le Courrier of C.R.B.P., n_ 38 September 1994, Cameroon)

1.2 World trade

World production of plantain was estimated in 1985 at 25 million tons. Of this 16.6 tons was projected for Africa; Latin America was the second place producer at 4.1 millions of tons (FAO, 1987).

Plantain cultivation is not limited to big plantations but is often grown in small orchards which sometimes go unnoticed (WILSON, 1983). The usual production takes many forms (Chataigner, 1988):

- Next to or behind the home in a garden (generally a maximum of 50 plants),

- On cleared forest, or on swaths in association with other food production (coffee, cocoa).

These fields represent at least 95 percent of cultivation.

They are of modest size as growing areas vary from 0.5 to 4 ha (Tlu, Ira-Ekona, 1987; N'guessan et al., 1993).

Plantain is usually cultivated first for self-consumption, in random form, in rotation followed by fallow. The surplus of available production is sold.

In this crop system of extensive cultivation, densities measure a maximum of 1000 plants to the 1666-advocated yield. Yields are from 3 to 54 tons/hectare. Peasants who use low technology input on poor soil grow the lowest limit. Invariably, technology with high inputs, intensive production to obtain high yields is rarely transferable to peasants due to required initial funding required (WILSON, 1983).

High technology in the pure culture of plantains is rather uncommon in Africa. It is extended to the Caribbean and Latin America who are oriented to export trade.

In despite of its increases, production for export represents a very small proportion of the harvest. The types of distribution are:

- Traditional. Plantains are sent from efficient producing countries to others that produce little or no banana crops. These are mostly border countries: Cameroon to Gabon, Côte d'Ivoire to Burkina Faso;

- Modern (Packaged in cartons). Plantains are sent to North America and Europe. Latin America has a long history of this export and big plantations are dedicated to trade. Andean zone is the biggest producer in the American continent, but export is only 4 percent of production (Lescot, 1993).

The marketing of the production in the Southwest district of Cameroon, stems from five principal productive strategies (TEMPLE and al., 1983):

- Subsistence strategies where small family production is used for the household food-supply;

- Pioneer strategies of migrant farmers who are in zones, which grow plantains;

- Firm strategies where farmers have consolidated their cultivation extension process;

- Diversification strategies of farmers often with a main non-agricultural activity who try to invest in plantain;

- Food-producing strategies in garden or small food-growing plots to supplement family food supplies.

These strategies depend on four variables:

- Objective of the farmer;

- Structure of production;

- Cultivation system;

- Marketing process.

Table 5. : Economic viability of production systems (cost per hectare)

	Extensive forest system (1st cycle)	Extensive forest system (3rd cycle)	Intensive system (1st cycle)
Production
Number of plants sown	900	900	1666
% of harvested plants	95	40	90
Weight of cluster (kg)	9,3	8,0	8,0
Production (kg)	7 951	2 880	11 995
Value (FCFA)	214 677	77 760	323 865
Changing price
Drops
Number	900	225	1666
Value (F CFA)	45 000	11 250	83 300
Insecticide
Quantity (kg)	0	0	33
Value (F CFA)	0	0	82 500
Total cost (FCFA)	45 000	11 250	165 800
Gross (1) (FCFA)	169 677	66 510	158 065
Labour (days)*
Clearing	25.0	7.0	0.0
Making holes	15.6	4.0	29.0
Sowing	9.4	2.3	17.3
Weeding	22.5	15.6	41.7
Treatment	0.0	0.0	1.3
Harvest	40.6	17.0	71.5
Total (2) (F CFA)	113.1	45.9	160.8
Productivity per working day	1 500	1 449	983
(1)(2) (F CFA)

*Note: Technical coefficients are derived from surveys under actual conditions. The cost retained for plantain is 27 CFA/kg, average price over the production period from September to May at the field border 100 FCFA = 2 FF (French Francs). The duration of a working day is 5 hours. The time of clearing (semi-mechanical) is 51 working days spread over 3 years. Drops or losses are defined as number planted per hectare in the first cycle and number of replacements per hectare Fr the second cycle.

Source: TEMPLE et. al., 1993

The requirement for labour per hectare for the plantain is smaller than that required for most tropical species (See Table 6).

Table 6. Labour requirement for tropical crops

	Plantain	Cassava	Maize	Rice
Day labour /ha	80	310	122	162
Days work/ton	20	31	122	62

Source: Johnston, 1958

The most extensive systems of production could hardly challenge in the short term the present forestry system (TEMPLE and al., 1993).

Table 7: Evolution of plantain production in the most important producing countries between 1971 and 1979 (in thousands of tons) (*)

					% variation
	1971	1977	1978	1979	(1971-1979)
World	16 05	19 536	20 275	20 584	28
Africa	10 404	12 640	13 011	13 285	28
Cameroon	694	950	950	955	38
Gabon	807	1100	1150	1200	48
Guinea	177	212	220	222	25
Côte d'Ivoire	653	750	800	800	23
Kenya	168	205	215	225	34
Nigeria	1635	2000	2100	2150	30
Rwanda	1656	1896	2043	2127	28
Tanzania	539	746	733	746	38
Uganda	2650	3100	3192	3192	19
Zaire	1191	1433	1405	1420	18
North and Central America	1237	1418	1519	1464	18
Cuba	60	130	134	134	123
Dominican Republic	529	531	610	550	4
Haiti	189	198	198	162	5
Honduras	110	153	160	162	47
Puerto Rico	101	102	101	100	35
South America	3210	3897	4255	4336	35
Bolivia	100	153	165	173	73
Colombia	1619	1844	2192	2236	38
Equador	445	770	796	790	77
Peru	654	700	705	742	13
Venezuela	363	406	372	369	2
Asia	1197	1577	1486	1495	25
Burma	406	501	404	425	5
Philippines	402	270	270	270	(-33)
Sri Lanka	389	806	775	800	105

(*) Countries producing more 100,000 tons per year. Source FAO, 1979.

In many producer countries, plantain is used for consumption. Global data often conceal the importance of consumption in certain regions. Consumption is generally highest in producing zones (Melin and Djomo, 1972; Guillemot, 1976). Recent studies indicate that consumption is increasing in urban areas, except within principal production regions (Sery, 1988).

Table 8: Plantain and cooking banana production and utilisation world-wide by region and Africa by country (FAO, 1985)

REGION/COUNTRY	PRODUCTION (`000 t)
	Total	Export	Feed	Food	Processed
AFRICA	12867,0		28,9	8194,5	2387,6
Cameroon	970,0			630.0
Central African Republic	65.0			52.0
Congo	62.0			55.8
Gabon	170.0			161.5
Ghana	450.0			585.0*
Guinea	235.0			188.0
Guinea Bissau	25.0			20.0
Ivory Coast	850.0			680.0
Kenya	225.0			216.8
Liberia	32.5			29.9
Malawi	17.5			15.8
Nigeria	1420.0			1420.0
Rwanda	2200.0			534.0	1600.0
Sierra Leone	25.0			23.8
Tanzania	1000.0		20.0	730.0	100.0
Uganda	3410.0			1700.0	511.5
Zaire	1480.0		8.8	1147.0	176.1
ASIA	1718.0			1288.3
N/C AMERICA	1615.1	23.9	87.9	1119.0
S AMERICA	4036.9		311.1	3258.3
OCEANIA	1.3		0.3	0.8

*Numbers includes imports.
Table 9- Estimated annual per-person consumption of starchy staples in many countries of the tropics (FAO. 1971)

Country	Per-person consumption (kg/year)
	Plantain*	Cassava	Yam	Maize
Brazil	39,3	55,5	--	19,2
Cameroon	76,5	104,0	39,8	48,6
Colombia	61,5	21,4	6,0	16,6
Costa Rica	31,2	6,2	--	54,9
Congo	24,6	241,7	--	3,3
Dominican Republic	143,4	27,4	4,5	7,0
Ecuador	65,0	12,4	--	7,3
Gabon	153,6	192,8	52,5	3,6
Ghana	80,7	104,8	97,2	35,5
Haiti	75,1	23,2	4,3	47,3
Ivory Coast	99,5	71,7	166,3	38,7
Puerto Rico	27,0	1,9	4,2	2,3
Rwanda	296,8	15,8	--	12,8
Tanzania	86,8	19,5	--	50,7
Uganda	237,2	95,7	51,6	14,7
Zaire	62,7	264,4	16,2	15,0

* Numbers for Costa Rica, Dominican Republic, Rwanda, and Uganda include banana.

1.3 Primary product

The traditional consumption almost represents the usual form of utilisation. Plantain is consumed regardless of its ripening stage. The green or ripe fruit is boiled in water, chopped up or pounded into a homogeneous paste and may mixed up with peanuts, cassava or yam.

Riper plantain is fried in oil after being chopped, mashed or mixed with wheat, cassava or maize flour. The pulps may be cooked by wrapping them in banana leaves. Plantain can also be toasted or dried up.

There is an abundance of recipes for plantain. Naturally certain plantain varieties are preferred to others for different dishes. For example, True and false Horn with bigger fingers are mashed more often than French plantain. The latter are used in recipes that call for chopped plantain. The ripe fruits are used in making traditional wines in Central Africa.

Beyond the usual alimentary utilisation, the different parts of the plant or the fruit are used in traditional medicine in West Africa:

- The coal obtained from the burnt skin of the fruit is used to cure dysentery;

- The juice obtained after cooking the green fruits is recommended for urinary incontinence;

- The ashes of the burnt skin, after being mixed with some water and strained with a low fire, provide a potash which is used in medicines, soap works, and in sauces.

Industrial level chip manufacturing is done in Latin America (Badia, 1985). Chips are more and families in Africa make more. These are sold in the streets or by small and medium companies, which deliver them to supermarkets.

The pulps can be transformed into flour and may be used in various dishes such as nursing porridge (Kiyingi, 1985). The pulps of the ripe fruit can be used in making industrial alcoholic drinks such as wines and liquors.

1.5 Requirements for export and quality assurance

Quality criteria are taken into account when fixing prices at all stages of commercialisation. Quality is judged by objective and subjective criteria, which are likely to change from one region to the other. The opinions of the specialists in the field cover characteristics:

- Cooking flavour and eating habits;

- The physiological maturity at harvest (for example, the degree of filling of the fingers).

The perception of quality will also affect commercial activity:

- Producers prefers high yielding plantains cultivars which have greater resistance both to pests and to drops caused by wind and hurricanes;

- Intermediaries focus on degree of maturity, transport distances and the distribution deadlines. The plantain crops already ripe at the producer level are depreciated because they will be too mature before delivery at the urban market.

The characteristics at harvest and the state of freshness are two basic criteria taken into consideration in the commercialisation value of the plantain.

Traditional criteria identify quality through reference marks of the level of filling, the degree of roundness of the fingers and the colour of the pulp.

Three qualities that define decreasing commercial values are:

- The well filled cluster with well-coloured pulp (Quality 1) (See Figure 9a+b);

- The cluster with medium filling and pulp coloration (Quality 2);

- The lean cluster with a poorly coloured pulp (Quality 3).

Cross and lengthways sections of median portions of corresponding fingers (cultivar Orishele, a «False Horn» plantain) are shown in Figure 10a-c.

Sometimes professionals add another parameter, which they call «drop» made up of very early and immature clusters from fallen trees (hurricanes, winds). Sometimes these crops are sold when supply is very weak during the low production season (Sections of fingers are shown in Figure 11a+b).

Figure 9a+b:
Well developing bunches of plantain (quality 1). Showing caracteristics of freshness. First cultivar French clair ("French"). Second cultivar Orishele (false "Horn"); See the splited finger in first hand showing a well coloured pulp

On the banana and the plantain tree, one can notice an increase of the weight of the cluster, of the filling of fingers and the coloration of the pulp during the development of the bunch.

Quality 1 corresponds to the well-advanced physiological maturity and homogeneous filling;

Quality 2 has an intermediary filling and pulp coloration;

Quality 3 comprises clusters of various characteristics:

- Lean fingers with coloured pulp. The plantain is quite advanced in physiological maturity but its yield is low to poor, following bad growth and development conditions (nutritional deficiencies, unfavourable bioclimatology, pest attacks);

- Lean fingers and pale pulp indicating homogeneous physiological maturity resulting from a too early harvest or taken from a banana tree fallen before successful development of the bunch.

The degree of filling is the simplest parameter to observe at markets, because it can be detected from a distance of several meters. It is not necessary to break a finger. The pulp coloration can confirm for the client the maturity of the cluster.

The impact of quality on the commercial value is undeniable. Reports of prices at all stages of the market showed that the clusters of Quality 2 and 3 are worth when compared to those of Quality 1 around 30 percent and 45 percent to 55 percent respectively (N'da Adopo and al. 1997).

When buyers and sellers are bargaining about the maturity of a cluster, freshness is ranked second. The green fresh cluster (See Figure 9a+b) has:

- Brilliant and clean appearance;

- Peducles, which are, firm and can still support fingers in an erect position;

- A shaft which shows a white or whitish-coloured humid wound when it is cut.

The cluster which has lost freshness (See Figure 12) shows:

- A dirty appearance. There are traces of shocks and wounds inflicted during the various manipulations. These marks are apparent, dark-coloured or black further aggravated by heat and dehydration;

- A dry, soft shaft;

- Falling fingers.

Figure 12:
Type false "Horn" bunches showing signs of loosing freshness.

A study initiated in 1992 in Douala (Cameroon) and in the main zones of the Coastal and Southwest districts which supply towns with plantains, translated the seasonal variations of quality perception by the local producers (N'da Adopo and al., 1992).

These two districts were supplying respectively 63,500 and 245,000 tons (Source: Minpat, Direction of Planning, 1985) or 6.4 and 30 percent of the production of the country. 70 percent of the plantain consumed in Douala comes from the Southwest (Lendres, 1990; CRBP, 1996).

Producers and intermediaries in rural zones generally recognise the rainy season as being the period during which clusters are of best quality. The rainy season corresponds in fact to the period during which the banana tree gets a lot more water. The alternate rain-sun pattern creates good conditions to fill and mature the fingers of the bunches. The study concluded that quality is synonymous with good development, good filling and turgid characteristics of the cluster.

Table 10 (a, b and c) presents the periods and percentages of the clusters of Quality 1 cited by the producers of Zones I, II and III (See Figure 13). Zones IV and V have not been studied, as their production is marginal compared to the first three.

Figure 13: Borders of the major areas of South-West and Coastal Districts which provide Doulas with plantains

Figure 13b: Calender of quality and percentage of its distribution according with the perception of producers in the major areas providing Douala with plantains (N'Da Adopo et al., 1992)

Consumers in Douala in their majority designated the dry season, as the period during which the rate of Quality 1 clusters is the highest. The dry season (December to March) corresponds to the peak production period (up to 2 times more plantains than in rainy season). During this peak period, banana trees often suffer from heat and a certain proportion of clusters do not reach maximum filling.

In the rainy season (June to September), conditions are more conducive for better development of the fruits; but production is weaker. Producers often harvest when filling is still insufficient, because they are sure to sell the cluster.

Table 10: Calendar of quality and percentage of its distribution during the year in the surveyed production zones
+ = Period of large proportion of banana plantain of Quality 1
- = Period of small proportion of banana plantain of Quality 1
a) Regions of Kumba, Muyuka and Muyenge (Zone I)

Areas

J

F

M

A

M

J

J

A

S

O

N

D

Muyenge

- 20 à 30

+

+

+

50 à 90 + +

Liliale

- 20 à 40

-

+

+

60 à 85 -

Likoko

- 20 à 40

-

+

60 à 80

- - -

Bafia

- 25 à 30

-

+

50 à 90

+ - -

Muyuka

- 25 à 35

-

-

-

50 à 90 + +

Yoke

+

- 30 à 70

-

+

50 à 90 + +

Owe

-

- 30 à 40

-

-

+ 50 à 90 +

Kumba

+

- 25 à 40

-

-

+ 50 à 90 +

Mabanda

+

+

-20 à 40

-

-

- 80 à 90 +

Molyko

- 30 à 50

-

+

+

+ 50 à 90

+ + +

Mutengene

+

+

-

40

-

+

+

65 à 85

+ +

Tiko

+

-

-

20

-

+

50 à 90

+

B) Region of Tombel (Zone II)

Areas

J

F

M

A

M

J

J

A

S

O

N

D

Buba 1

- 40

+

+

50 à 70

+ +

Buba 3

- 25 à 50

+

+

80 à 90

+ - -

Ebonji

-

45

-

+

+

75 à 95

+ +

Ngap (_)

+

80

+

+

-

30 à 50

-

+

Mile 20

-

+ 90

+

-

Bulutu

-

30

-

+

+

70

+

+

+

-

Mahole

-

30

-

+

+ 50 à 70

+ +

Ehom

-

40

-

+

+

75

+

+

-

(_) The soils of this area contain often-excess water during wet season.

c) Region of Penda Mboko (Zone III)

Areas

J

F

M

A

M

J

J

A

S

O

N

D

Penda Mboko

-

- 40

-

+

+

80

+ +

Matouke

+

+

-

50

-

+

+

+

+

+

Banana plantain has not been covered by well-defined international criteria, as is the case for export banana. One may adapt existing specifications to plantain, on the basis of current methods and data. Côte d'Ivoire specifications concerning banana plantain for export (NI 01.02.001) mainly applies the regulations of fresh bananas intended for export.

Fingers should:

- Be normally developed, full, firm, fresh, green and free from ripeness marks, black spots and rust marks;

- Be healthy without scratches, wounds and no symptoms of sunburn. Crops should be free of storage pests or marks affecting the commercial value;

- Be clean, free from processing products or visible foreign matter and dust;

- Held by healthy peduncles which are not broken, twisted or mouldy. Fingers should not be missing inside hands.

In the traditional sector, ripeness for harvest of several cultivars of reduced or medium size (Corne 1 and 4 in Côte d'Ivoire, French Sombre and Bâtard of Cameroon, Orishele of Nigeria) is reached between 75 to 95 days after discovery of the last female hand.

The formula of thermal sums used to forecast the harvest of export bananas (Ganry, 1978) was tested on plantain at CRBP (N'da Adopo, 1993).

The daily thermal sum is equal to:

(0.4 X t_ maxi + 0.6 X t_ mini) - 14

Is defined with a threshold of 14_C, the temperature threshold for growing bananas.

The corresponding features with the French sombre cultivar between the calculated thermal sums, the intervals since flowering (stage of last female hand discovered), the weight of clusters, the degree of fingers filling and pulp coloration (in accordance to IRFA colour scale on banana, Figure 14a) and quality criteria defined by professionals of the traditional sector, is summarised in Table 11.

Figure 14a: Colorchart of banana pulp according with french norm for export (IRFA, 1980)

Figure 11a+b and Table 11 present increasing characteristics of filling (in accordance to Figure 14) and coloration observed during this trial.

Figure 14: Schematic cross section of banana according to different levels of development (IRFA, 1980)

Table 11: Quality at harvest of the French sombre cultivar in the traditional sectors (characteristics per official regulations)

Quality			«Drop»		3		2		1
Thermal sum (_C)			800		900		1000 à 1100		1200
Interval flowering-harvest (days)			61		69		77 to 84		94
Level of filling			< 3/4		3/4 lean		3/4 light to 3/4 full		3/4 full to 4/4
Pulp coloration			< 5		5 to 5,5		6 to 6,5		7 to 8
Medium weight of clusters (kg)			13		15		17		17,2
Medium living leaves at harvest		6,4		6,4		5,47 to 5,08		4,14