Evaluation of the Susceptibilities of Some Selected Eggplant Accessions to Major Insect Pests in the Field and Under Screenhouse Conditions.

Abstract

The scarlet eggplant, Solanum aethiopicum, holds significant importance for indigenous communities in Africa. Although its production is widespread, it faces a common challenge: depredation by insect pests, including the destructive eggplant fruit and shoot borer (EFSB), Leucinodes spp. The larvae of this pest feed by tunnelling into tender shoots or boring into fruits, leading to plant wilting or death and loss of fruit value and aesthetics. Farmers often resort to synthetic insecticides to manage these insects, but this approach has negative implications, such as residues in fruits, the development of insect resistance, and environmental pollution. Consequently, there is a growing need for safe, cost-effective, and sustainable management options. One such option is host plant resistance, a natural phenomenon based on the plant’s self defence mechanisms. In this study, the performance of five eggplant accessions (RV100213, RV100248, RV100250, RV100307, and Legon1) was evaluated against EFSB. The evaluation was conducted in open fields at the Forest and Horticultural Crop Research Centre (FOHCREC), Kade, and under screen-house conditions during two cropping seasons in 2022. Plant growth parameters, fruit yield, insect damage or incidence, and plant hardiness were used as indices for plant performance against EFSB. The data collected indicated significant differences (P ≤ 0.05) in plant height and the number of leaves among the accessions in both the open field and screen house experiments. Fruit yield also varied significantly among the accessions. The percentage of EFSB infestation ranged between 29 – 45 for shoots and 20 – 62 for fruits. Generally, infestation on shoots and fruits for all the tested accessions was considered high and were ranked between moderately susceptible to highly susceptible on a 6-point scale (1-immunity, 2-resistant, 3 Moderately resistant, 4-moderately susceptible, 5-susceptible, 6-highly susceptible) for host plant resistance against the eggplant fruit and shoot borer. The findings of this study can be used to determine the optimal time to initiate management procedures to prevent ESFB infestation in the fields