Two types of infections must be discerned:
1) Those which act on the plant by causing a bad development of the bunch;
2) Those which affect the fruits directly before or after the harvest.
Bad nutrition and poor soils cause a delay in the filling of the fingers in conformity with the age of the bunch. The fruits are thin and the pulp is coloured or even with an advanced coloration (yellow dard in some cases in the phenomenon of "yellow pulp").
The bunches often display a poor appearance. Ripening frequently happens on the plant before the harvest stage.
Water outages in the soil and continued droughts lead to similar effects.
Parasites and spoilers: Attack of underground organs
Weevils and nematodes attack respectively the stumps (formation of galleries) and the roots of the banana trees. The incidences on vegetation and the profits are disastrous (Kehe, 1985; Sarah, 1985):
- Section and breaking of the tubes conducting the sap;
- Early destruction of the bulb;
- Section and destruction of the roots.
The consequences are:
- A bad water and nourishing alimentation from the soil; banana trees remain puny and they vegetate. The production becomes inadequate and the plantation gets old quickly.
- The plants fall down with the least wind blow, chiefly from the flowering period when the fruits start to be filled and when they begin to increase in weight.
- The bunches from those banana trees can be classified as Quality 3.
Aerial agents
Black Sigatoka, a fungi disease of the foliaceous system causes falls of the production that can reach more than 50 percent. There's a defect of filling with the fruits of affected plants and they can no more reach their optimum size. Some attacks cause an important destruction of the plantations in Central America, reducing practically to nothing plantain exportations from affected plantation in Honduras (Stover, 1985). Bunches coming from those plantations can no more satisfy the minima requirements in quality and size. Moreover, they grow ripe too early when they're being transported (Bustamente, 1985).
Two types of infections must be discerned:
1) Those which act on the plant by causing a bad development of the bunch,
2) Those which affect the fruits directly before or after the harvest.
Bad nutrition and poor soils cause a delay in the filling of the fingers in conformity with the age of the bunch. The fruits are thin and the pulp is coloured or even with an advanced coloration (yellow dard in some cases in the phenomenon of "yellow pulp").
The bunches often present a dim aspect. Ripening of the fruits frequently happens on the plant before the stage of habitual harvest.
Water outrages in the soil, continued droughts, and lead to similar effects.
Two types of affections must be discerned:
1) Those which act on the plant by causing a bad development of the bunch,
2) Those which affect the fruits directly before or after the harvest.
Bad nutrition and poor soils cause a delay in the filling of the fingers in conformity with the age of the bunch. The fruits are thin and the pulp is coloured or even with an advanced coloration (yellow dard in some cases in the phenomenon of "yellow pulp").
The bunches often present a dim aspect. The fruit ripening frequently happens on the plant before the stage of habitual harvest.
Water outrages in the soil, continued droughts, and lead to similar effects.
In some areas fall in plantain production leads to increases in food prices (Mouliom Pefoura, 1985).
In the usual traditional plantain crop system, it is impractical for the producer to resort to fighting pests with chemical products suited for banana or plantain plantations intended for exportation (Foure, 1985). Those methods require:
- The use of systematic fungicides by pulverisation or spreading;
- Aerial treatment.
The impact of the disease on the commercial level appears more pronounced in industrial plantations (in particular for exportation) than on the traditional market:
- Lack of average (norms);
- The affected bunches are classified in the category corresponding to the filling level and to their pulp coloration and then sold or consumed by people without any other quality concerns.
When fruits are attacked they become enormously undervalued:
- Tip disease;
- Dry rots of the ends of the fingers;
- Black spots; at an advanced stage of development, the skin is ready to crack;
- Anthracnose leads to black marks. The development of the disease causes the rottenness of the fruit when getting ripe during the maturity period).
Fungi attacks are particularly noticeable during the wet season. They cause quicker ripening of the fruit before harvest. Direct infections on bunches which provoke a rather repulsive aspect of the fingers are the only causes of rejection of the crop in that traditional channel. Removing the residual floral pieces of the tips of fingers with the casing of the bunch in a plastic protection at the end of the flowering period, treatment with fungicides, work to fight those diseases.
If removing residual floral pieces can't be done (a few minutes maximum per bunch) by the traditional producer himself, by means of a ladder (which he can make by himself), the buying of plastic protection cases and treating products and their employment, may not be profitable when taking into account the prices of banana plantain in the traditional channel.