Efficacy of Custard Apple Extract Against Plutella xylostella L.

Abstract

Organic crop production is limited in substances for plant pest and disease control. This study was aimed at evaluating the efficacy of custard apple leaf and seed extracts against diamondback moth to provide guidelines for their use in organic agriculture and as an alternative for farmers to use substances. 2 varieties of custard apple, the Nang variety and the Phet Pak Chong variety, were studied, testing leaves and seed parts. A completely randomized design (CRD) with four replications was used. The rate of extract was varied to assess its effect on diamondback moth control. For the leaves, the efficacy of fresh and dried leaves soaked in water for 24 hours was tested. It was found that extracts from both fresh and dried leaves had a little efficacy. Fresh leaves and extracts of the Nang variety at the rate of 10% w/v and the Phet Pak Chong variety at the rate of 5% w/v were 37 and 61 % effective in controlling diamondback moth, respectively. Dry leaf extracts of both varieties at rates of 0.5-10% w/v were more than 40 % effective. For custard apple seeds, the efficiency of seed extracts extracted by soaking in water and ethanol for 24 hours found that the Nang variety's ethanol extracts were more effective than aqueous extracts, with the 10% w/v extract causing up to 100 % diamondback moth mortality. The Phet Pak Chong variety's aqueous seed extracts at 20% w/v and ethanol seed extracts at 5 and 10% w/v were highly effective, with efficiencies of 76 %, 81 %, and 95 %, respectively.