Effects of Tephrosia vogelii formulation with rabbit urine on insect pests and pollinators of sesame in Singida, Tanzania

Abstract

This study assessed the effects of Tephrosia vogelii (T. vogelii) formulation with rabbit urine on insect pests and pollinators of sesame in a field experiment in Singida, Tanzania from February 2021 to July 2021. The field experiment consisted of five treatments arranged in a Randomized Complete Block Design (RCBD). The field experiment treatments included (application rates are w/v for T. vogelii; v/v for rabbit urine; 2 mils/l for synthetic pesticide) 10 % T. vogelii, 50 % rabbit urine, 10% T. vogelii + 50 % rabbit urine, water (control) and synthetic pesticide [Duduba 450 EC (Cypermethrin 100g/l. + chlorpyrifos 350g/l)], which was used as a check. The results show that sesame plants sprayed with biopesticide formulations significantly (p≤0.001) possessed a smaller number of insect pests (Antigastra catalaunalis and Alocypha bimaculata) same as synthetic pesticide. The larger numbers of pollinators (Apis mellifera, Ornidia obesa and Diadegma semiclausum) and natural enemies (Tapinoma sessile and Coccinella undecimpunctata) was recorded in sesame plants sprayed with biopesticide formulations than those sprayed with synthetic pesticide. Conversely, the findings of this study revealed that plots treated with 10% T. vogelii + 50% rabbit urine produced the highest (740.59 kg/ha) sesame yield, while those in the control gave the lowest yield (672.78 kg/ha). Therefore, this study suggests that T. vogelii formulation with rabbit urine can be used by the resource poorly-endowed smallholder farmers as an alternative strategy to control sesame insect pests, while maintaining high yield and beneficial insects like pollinators.