A Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Master’s in Life Sciences of the Nelson Mandela African Institution of Science and Technology
The research assessed the potentiality of four insecticidal plants (Dysphania ambrosoides, Hyptis Suavelons, Ocimum suave and Sphaeranthus suaveolens) with field margin in attracting natural enemies, controlling insect pests and their contribution on yields in common bean production. The study findings indicated that field margins with Ocimum suave significantly (P ≤ 0.001) attracted more natural enemies than the other three insecticidal plants. Also, there was a significance (P≤0.001) difference in incidence and severity of foliage pest damage across the treatments. Less incidence and severity of foliage pest damage was recorded in Ocimum suave treatment while the highest incidence and severity of foliage pest damage was recorded in the control. Results on yields parameters were significantly different (P ≤ 0.001) across the treatments in which Ocimum suave had significantly number of pod per plants, number of seeds per plants, 100 seed weight and grain yield (Kg/ha) as compared with the control. The study findings demonstrated the effectiveness of field margin plants in attracting natural enemies, reducing pest incidence and severity of foliage damage as well as increasing bean yields. Therefore, the use of field margins with desired insecticidal properties can offer a sustainable way to conserve natural enemies and control insect pest in agricultural ecosystems.