Assessment of the effectiveness of garlic as a companion plant for controlling aphid infestations in chilli crops in Rwanda: a case study of the Gicumbi district

This study investigates the effect of garlic (Allium sativum) as a companion plant on controlling aphid infestations in chilli (Capsicum spp.) crops in Gicumbi District, Rwanda. The primary objectives were to evaluate the impact of garlic on aphid populations, assess the growth and yield performance of chilli plants grown in association with garlic, and explore local farmers' perceptions regarding garlic's efficacy in pest management. Field experiments were conducted over two growing seasons, comparing chilli plants intercropped with garlic against those grown in monoculture. Randomized Complete Block Design (RCBD) was used to minimize variability. Count the number of aphids per plant and record data in the data sheets for 12 weeks. Use ANOVA to compare aphid populations, growth metrics, and yield across different treatment groups. Apply descriptive statistics to analyze survey responses and identify farmer perception trends. Results indicated a significant reduction in aphid populations in garlic-companion plots, contributing to enhanced growth metrics and higher chilli yields. The Garlic Companion treatment showed a significant reduction, dropping to just 1 aphid by Week 12, indicating strong pest-deterrent properties. Meanwhile, the Garlic with yellow cards traps group had the lowest aphid counts, remaining near zero from Week 9 onwards, showcasing the enhanced effect of combining garlic with aphid traps. Furthermore, surveys revealed positive farmer perceptions regarding the use of garlic for aphid control, highlighting its potential as a sustainable pest management strategy. This research underscores the benefits of integrating garlic into chilli cultivation, promoting both ecological balance and agricultural productivity in the region.