Field bioefficacy of mahogany seed extract (Khaya senegalensis: meliaceae, (desv.) a. juss) for management of bollworm infestation on cotton in Zaria, Nigeria

Abstract

Field trials were conducted at two locations in Samaru (110 11'' N, 070 38'' E and 686m above sea level) and Maigana (110 10'' N, 070 37'' E and 675m above sea level) both in Northern Guinea Savannah ecological zone of Nigeria during the 2016 wet season to determine the effects of three concentration of aqueous Khaya seed extract (KSE) (20%w/v, 30%w/v and 40%w/v) on damage on cotton (SAMCOT 9) by bollworms. The experimental design was strip plot fitted into randomized complete block design. A total of four sprays at two weeks interval beginning from 9WAS (which corresponded to the period of formation of first square to the detection of first flower) were applied. Data were recorded on the number of terminal shoot damage, number of damaged shed squares, number of damaged shed cotton bolls and number of matured green bolls damaged by bollworms. There was no significant difference in the number of terminal shoot damaged by spiny bollworm (Earias spp.) from spray application of Lambda cyhalothrin, KSE and the untreated control. Significant reduction in the number of shed cotton squares, shed cotton bolls and matured green bolls damaged by bollworms were observed on Lambda cyhalothrin and 40%w/v KSE sprayed plots than the other treatments and the untreated control.