Efficacy of Plant Extracts for the Control of Pepper Insect Pest (Green Peach Aphid (Myzus persicae L.)

Aphids pose significant threats to crop productivity, necessitating effective and sustainable pest management strategies. This study investigated the repellent properties of neem and papaya leaf extracts on green peach aphids and the impact of the extracts on plant growth in pepper (Capsicum spp.). The experiment involved 7 treatments and 3 treatment replications with varying concentrations of neem and papaya extracts (6.5 v:v, 7.5 v:v, and 8.5 v:v) compared to a control group (Distilled water). The Randomized Complete Block Design (RCBD) was used as an experimental design. The study site was Cuttington University’s College of Agriculture Research site. The distances between plots and blocks were 0.6 m and 1 m, correspondingly. In the laboratory bioassay, results uncovered distinct trends, with the control treatment exhibiting the highest mean aphid count (41.0), while neem 8.5 v:v (6.0) and papaya 8.5 v:v (8.1) treatments established substantial effectiveness in reducing aphid populations. The highest mean aphid counts following biopesticidal application were 48.0 and 76.7 after 1 and 2 weeks, respectively and were recorded in the untreated control plots, while the lowest mean aphid counts were 21.3 and 6.0 after 1 and 2 weeks, respectively. Furthermore, neem 8.5 v:v treatment consistently showed the highest mean values across plant height (16.2 cm), leaf length (8.2 cm), leaf width (5.2 cm), and repellency index (3.0), indicating potential positive impacts on plant growth and repellency. Untreated control measured the lowest values for plant height (13.8 cm), leaf length (6.0 cm) and repellency index (1.0). The study demonstrated the potential of both extracts to suppress aphid populations and enhance plant growth. Applying these natural extracts as part of an integrated pest management (IPM) strategy can be beneficial for controlling aphid infestations in pepper crops. Their use as repellents can reduce aphid populations, minimizing potential crop damage and yield losses.