The stem borer Eldana saccharina infestation level on Borotou-Koro sugar complex is very alarming. However, effective control methods are not yet very developed against this pest. In order to better understand and guide the search for a lasting solution, it is necessary to master the biology and ecology of this insect pest. It is in this context that this study was conducted at Borotou-Koro agricultural integrated unit. It aims to inventory the natural enemies of Eldana saccharina, in this case the parasitoids present on the sugarcane plots. To do this, borer larvae and pupae were collected from the sugarcane plots and reared in the laboratory. The results obtained indicate that three Lepidoptera species of stem borer are present on the Borotou-Koro sugar complex: Eldana saccharina (98.4%), Sesamia calamistis (1.53%) and Sesamia inferens (0.07%). The parasitism rate of E. saccharina larvae and pupae is low (3.29%). Six species of parasitoid auxiliaries of Eldana saccharina have been identified including a larval parasitoid (Sphaephoria sp), a larval-pupae parasitoid (Lycoriela auripila) and four pupae parasitoids (Trichopeza sp, Proctotrupes sp, Proconura nigripes, Psilochalcis sp). Fusarium spp has also been identified as a parasite of Eldana saccharina larvae. These six parasitoid species come from two families which are the Diptera estimated at 3.32% and the Hymenoptera which represents 96.68% of the percentage of parasitoids encountered. Thus, the Borotou-Koro sugar complex is full of several species of Eldana saccharina parasitoids on these sugarcane plots. Eldana saccharina larvae and pupae rate of parasitism is substantially identical for all the varieties of cane encountered. However, the parasitism rate of pupae varies greatly from one sector to another and is higher in rainfed conditions than in irrigated conditions.
Yam (Dioscorea spp.) occupies an important place in the diet of the populations of Côte d'Ivoire. However, during storage, significant losses due to fungi are observed. The objective of this work was to know if traders are aware of the difficulties they encounter during the storage of yam tubers. To do this, a survey was conducted in four communes in the District of Abidjan. It was found that more than 94% of traders encounter enormous difficulties, particularly rotting during the storage of yams before sale. This mainly soft rot (93.75%) causes the loss of 10 to 20% of stocks according to 56.25% of traders. Although 87.5% of the traders felt they knew the causes of the rots, fungi were not mentioned at all. This study is a preliminary study that could be a database for a possible study on the identification and control of these fungi responsible for post-harvest rots.
Cashew (Anacardium occidentale (L.), Anacardiaceae), a forest plant initially became a cash crop. The national production is in clear progression with the extension of cultivated surfaces. However, the yield remains low. This study aims to assess the situation of producers and cashew nut orchards in the regions of Bounkani and Gontougo. The plantations of selected producers have been visited. An investigation sheet has been completed. Some parameters related to producers and plots were evaluated. Eight sub-prefectures were visited and 240 producers interviewed. The age of the producers was between 30 and 50 years old and 61 to 67% of the producers were uneducated. Average densities of orchards visited ranged from 724 to 769 plants / ha. The highest yield of cashew nuts was obtained in orchards between 21 and 30 years old in the Gontougo region (356.72 Kg / ha). In the plantations visited, only herbicides were used as phytosanitary products. 3.70% of peasants used fertilizers in orchards. Asked about the presence of disease in orchards, 54.17% of producers in the Gontougo region and 51.24% in Bounkani found the diseases. On the other hand, at the level of the 73.96 and 97.52% pests respectively in the plantations of Gontougo and Bounkani observed the presence of pests in their orchards. The annual production of cashew was strongly influenced by the density of plantations.
Phoma sabdariffae Sacc. (Sphaerioidaceae) is the main pathogenic fungus agent of roselle (Hibiscus sabdariffa L. var. sabdariffa), in Gabon. It does induce wet rot on every part of the infected plant's organs. This work was initiated to evaluate in greenhouse the impact of this pathogenic fungus agent on 13 roselle cultivars through the study of some morphological and biochemical parameters of the fruits. Morphological parameters evaluated have been fruit's number, weight and contamination rate. Concerning biochemical study, parameters measured have been roselle fruit's acidity, proteins and phenolics compounds levels. The results revealed that excepted 3 cultivars VV1, RV1 and RR1, Phoma sabdariffae caused significant decrease in the fruits number and weight of most of the roselle's cultivars. The decrease rates have been higher than 60% and 20% respectively. The improvement in acidity, protein and phenolics compounds levels were not significant, in contrary to those of the 3 cultivars above mentioned. In these 3 roselle's cultivars, biochemical parameters (pH, oxalic acid, ascorbic acid, proteins and phenolics compounds) levels have been superior to 20%. This work showed the disastrous impact of this fungus on the roselle's fructification and revealed that, some of the cultivars of roselle bright develop resistance mechanisms against Phoma sabdariffae.