Distribution of three weevil species in the various growth stages and residues of plantains (Musaspp) in Littoral Region of Cameroon

Many people in the rural and semi-urban areas in the tropics depend on plantains and bananas as a staple food and as source of income. Bio-ecological studies such as quantifying insect pest numbers within-plants and with-in residues will help to reduce the amount of insecticides applied in plantations or farms. The distribution of three weevil species with respect to plantain growth stages and pre-/postharvest residues was studied in a researcher-managed and a farmer-managed farm. Adult weevil species were counted from the following growth stages; suckers, pre-flowered, flowered, and bunched plants; as well as from these residues; desuckers, pseudo stem stumps, and cut pseudostems lying horizontally on the ground. Although Cosmopolites sordidus is widely reported as the most economically important insect on bananas/plantains, there were significantly more Polytusmellerborgi compared to C. sordidus and Metamasiushemipterus (very rare). In both farms, highest numbers of C. sordidus were found on pseudostemstumps as well as on bunched plants. In all the growth stages, numbers of the different weevil species were not significantly different in both farms. Also, for the residues, except for desuckers, all weevil species were similar in both farms. We proposed therefore that for any effective management of C. sordidus, application of management techniques that will significantly reduce adult numbers should focus on harvested stumps and bunched plants.Keywords: Coleoptera, Cucurlionidae, Insect, Pest managemen

Potential of Dual-Purpose Organic Amendment for Enhancing Tomato (Lycopersicon esculentum M.) Performance and Mitigating Seedling Damage by Mole Cricket (Gryllotalpa africana spp.)

Aim: Efficacy of locally produced dual-purpose organic amendment for improving tomato protection and yield was compared with synthetic pesticides and fertilizers. Methodology: The experiment was setup as randomized complete block with three treatments (control, inorganic and organic) each replicated four times. Results: Treatment was negatively correlated with tomato seedling damage by mole cricket (r = −0.86), with 100% efficacy in the organic treatment compared to 90% in the inorganic treatment and 80% in the control (P = .05). Treatment was negatively correlated with tomato blight (r = −0.57), with 100% blight infestation in the control compared to 8% in the inorganic treatment and 25% in the organic treatment (P = .05). No tomato plant was damaged in the organic treatment, compared to 12.5% in the inorganic treatment and 29.1% in the control (P = .001). The total plant damage was negatively correlated with treatment (r = −0.97) and positively correlated with seedling damage (r = 0.90), blight (r = 0.57) and wilt (r = 0.97). The highest tomato yield occurred in the inorganic treatment with 43.9 t ha-1 and organic treatment with 38.1 t ha-1, which differed (P = .05) significantly from the control with 1.5 t ha-1. Tomato yield correlated positively with the number of leaves per plant (r = 0.66), but was negatively correlated with blight (r = −0.70) and wilt (r = −0.60). The highest number of leaves per plant was recorded in inorganic treatment with 30 and organic treatment with 28, compared to 15 in the control (P = .05). Treatment was positively correlated with number leaves per plant (r = 0.63), while the number of leaves was negatively correlated with blight incidence (r = −0.92). Conclusion: The dual-purpose organic amendment is an effective sustainable alternative for improving tomato protection and yield compared to inorganic inputs