Etat des lieux phytotechnique et phytosanitaire de la production du manioc (Manihot esculenta Crantz) en zones péri-urbaines de Haïti

Abstract

The diagnostic of the production of manioc (Manihot esculenta Crantz) in suburban areas in Haiti was made in this work. It was carried out by using surveys and field observations during the period from March to June 2017 in four agro-ecological zones of the country. The non-probabilistic (empirical) survey method with the snow ball technique was adopted for data collection. A total of sixty (60) producers were surveyed at a rate of 15 producers per study area. The agro-ecological areas were selected considering their level of production. The results of the survey showed that in the four agro-ecological zones, the men are the heads of exploitation at 90% and the women at 10%. The age range of the exploitation heads varies from 39 to 68 years old for an average of 52.3 ± 6.6. The area sown with cassava varies from 0.64 to 3.22 ha with an average of 1.6 ± 0.7 ha. The Indirect Valve (FVI) is dominant with an average of 58.25 ± 11.17 and 41.75 ± 11.18 for the Direct Valve (FVD) of the land. The average planting density recorded was 15 793 ± 3889 plants per hectare. A high planting density is noted by the fact that growers average 1.87 ± 0.52 cassava plants per pole and that after the recovery they do not shed. Cassava is grown in association in all surveyed plots. It is often associated with corn (Zea mays), unknown pea (Vigna unguiculata), peanut (Arachis hypogaea), gombo (Abelmoschus esculentus) and pigeon pea (Cajanus cajan). The inventoried rotation system indicates that 30% of the producers practice a succession of cassava after the cassava harvest. About 48% of the producers succeed with other crops (pigeon peas, sorghum and peanuts) after manioc and only 22% of producers practice a short fallow after the cassava harvest. Producers do not practice irrigation, chemical fertilizers or treat cuttings. Producers reported that Erinnyis ello, Phenacoccus manihoti and Rattus rattus are the pests that are causing more damage in their plots. The results of the observations show for all four areas that cerporiose is the most widespread disease in the plots observed with an average incidence of 20 ± 3% of plants attacked. Neosilba perezi is the second most aggressive bio-aggressor with an average of 17 ± 3%. P. manohoti has an incidence of 15 ± 3%. The incidence of bacterial blight cassava and Aleurodicus dispersus is 7 ± 8% and 7 ± 14%, respectively. In all four zones, only 17% of producers are using alternative forms of treatment. Approximately 17% of producers use chemical treatment and 67% do not use any form of treatment. The chemical treatment is based on insecticide (diazinon, sevin, ...) mainly against Erinnyis ello. The alternative treatment consists of a mixture plants extracts (neem + water + laundry soap + chili) always against E. ello. This work has highlighted some phytotechnical and phytosanitary problems that affect the yield of cassava. A set of recommendations and perspectives are being formulated to improve cassava production in the country to meet the growing demand for cassava in urban and suburban areas.