Utilizing local plant extracts to control Diamondback moth in round cabbage

Abstract

Diamondback moth (Plutella xylostella L.) with abbreviation DBM is a detrimental pest that mostly attacks cabbage and other vegetables in Brassicaceae family. The build-up of resistance in DBM due to continuous and indiscriminate use of synthetic insecticides have refocused farmer’s perspectives to plant based extracts. Plant extracts are generally compatible with natural enemies of pests therefore are considered eco-friendly. This study was done to evaluate the push effect of Garlic (Allium sativum L.), Chili (Capsicum frutescens L.) and Seaweed extract on the activity of DBM. All three treatments; chili extract, garlic extract, and seaweed extract were generally effective in controlling DBM than the reference group (control treatment). Separation of means by Student-newman-keuls (SNK) test showed that Diamondback moth (DBM) abundance under seaweed extract was significantly low (2.18±0.32, p< 0.05) followed by chili extract (3.22±0.43, p< 0.05). There was no significant difference in DBM abundance under garlic extract and control treatment. For defoliation, only control treatment recorded a significant increase in DBM population (5.40±0.64, p< 0.05). The other three plant extracts had similar low non-significant abundances (p> 0.05). Data on LAI did not show any significant differences in all the treatments meaning treatments did not affect LAI (p> 0.05). This study found that both seaweed and chili extracts were effective in controlling P. xylostella in round cabbage. Both extracts are recommended for use since they differ in their mechanism pathways to protect crops.