The cocoa tree (Theobroma cacao L.) is an economically, nutritionally and socially important crop. Currently, this culture is at the center of scientific debate because it is indexed to play a significant role in the phenomenon of deforestation observed in humid tropical regions. In order to contribute to its expansion while minimizing forest losses and protecting the environment, agroforestry systems integrating herbaceous or woody flora species have emerged as a better alternative. In this perspective, this study constitutes a contribution to the valuation of shade trees in the cultivation of cocoa while maintaining intact its productivity in the territory of Lubero. The objective of the study is to study the influence of shade trees on the morphometric parameters of pods in the ecological environment of Buyinga. To achieve this objective, observations were made at nine cocoa plantations chosen according to their degree of shade. With the exception of the number of pods per stem, the results show that there is a very highly significant difference in the means of the length of the pods, the circumference of the pods and the number of beans per pod in the plantations according to the degree of shading (p-value<0.05). Indeed, the average lengths of the pods are 24.83 ± 4.11 cm in moderately shaded plantations, 22.61 ± 4.38 cm in heavily shaded plantations and 19.20 ± 2.69 cm for plantations without shade (in broad daylight). The average circumferences of the pods are respectively equal to 27.99 ± 3.41 cm for plantations with medium shade, 26.47 ± 2.5 cm for plantations without shade and 26.46 ± 3.49 for plantations with strong shady. The average number of beans per pod is 38.95 in plantations with medium shade against 38.53 beans per pod for plantations without shade and 26.5 beans for plantations with strong shade. Despite the absence of significant difference in the number of pods per stem according to the degree of shade, cocoa plantations growing under medium shade induced a high number of pods per stem compared to other plantations. The average number of pods per stem is around 25.8 ± 7.25 for plantations with medium shade, 23.89 ± 6.03 for plantations with strong shade and 21.51 ± 7.44 for plantings without shade.
The objective of this paper is to determine the incidence and severity of the FAW (Spodoptera frugiperda J.E Smith) and to study the influence of the cropping system on the degree of infestation of FAW in the cultivated corn fields in Kivira locality. To achieve these objectives, 60 corn fields including 20 fields at the 4 leaf stage, 20 fields at the 8 leaf stage and 20 fields at the flowering stage were visited. At the end of the analysis, the results show that the number of diseased plants was significantly higher for the 8 leaf stage with an average of 7.44 plants compared to the other two stages of corn development. Likewise, in corn fields at the 8 leaf stage, the number of FAW larvae in an area of 25 m2 is much higher with an average of 9.79 larvae. As with the number of diseased plants and larvae, the study shows that the number of lesions per leaf at the 8-leaf stage is greater than the number of lesions per leaf at the other phenological stages. The incidence of Fall Armyworm varies significantly with the phenological stages and crop types associated with corn. The average incidence of FAW in fields at the 8 leaf stage is higher than in other phenological stages. The averages are 35.72%, 9.88% and 6.96% for the 8 leaf stage, the flowering stage and the 4 leaf stage respectively. The average severity index for the Fall Armyworm is 7.24%. The maximum value obtained is 22.53%. At the 8-leaf stage, the average severity of FAW is 17.57% compared to 2.32% for the flowering stage and 1.83% for the 4-leaf stage.