Efficacy of a botanical and biological method to control the diamondback moth (Plutella xylostella L.) in cabbage (Brassica oleracea var capitata L.) under open field conditions at Anse Boileau, Seychelles

Three field trials were conducted from August 2007 till December 2007, October 2007 till January 2008* and February 2008 till April 2008 at the Vegetable Research Station in Anse Boileau, Seychelles to evaluate the efficacy of one botanical and one biological method for controlling the diamondback moth (Plutella xylostella L.) in cabbage (Brassica oleracea varcapitata L.) under open field conditions. The treatments were Thuricide (Bacillus thuringiensis), garlic extract and the control repeated four times in a randomized complete block design. The results showed significant differences between treatment plots, where Thuricide was applied as compared to the other two treatments. The means percentage of head damage in the first two trials for Thuricide treatments was significantly lower (9, 10%) compared to garlic extract (89, 90%) and the control (94, 98%). In the third trial, the non-treated plots obtained a maximum mean percentage of head damage of 92%, followed by 74% for garlic extract and 13% for Thuricide application. These results demonstrated that the Thuricide application is effective for controlling the diamondback moth pest on cabbage.   Key words: Thuricide, diamondback moth, cabbage, pest.