STUDY ON THE EFFECTIVENESS OF SOME PROMISING INSECTICIDES AGAINST BRINJAL SHOOT AND FRUIT BORER AND ITS NATURAL ENEMIES

Abstract

The experiment was conducted in the central farm of Sher-e-Bangla Agricultural University (SAU), Sher-e-Bangla Nagar, Dhaka-1207 during the period from February to September, 2013 to evaluate promising insecticides in comparison with conventional insecticides for management of brinjal shoot and fruit borer (BSFB), Leucinodes orbonalis Guenee and their impact on natural enemies. The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications and six treatments applied at 7 days interval. The treatments were T1 (Acimix @ 1ml/L of water); T2 (Calipso @ 1ml/L of water); T3 (Neem oil @ 3mml/L of water); T4 (Neem Seed Karnel Extract @ 100g/L of water); T5 (Nexaid @ 1.5ml/L of water); T6 (Untreated Control). The result reveled that amongst newer insecticides Acimix @ 1ml/L of water was most effective in reducing shoot infestation (66.72%) and Calipso @ 1ml/L of water was found most effective in reducing fruit infestation by number and weight (68.56 and 61.04%), over control followed (66.56, 53.7% respectively) by Acimix, whereas Neem Seed Kernel Extract @100gm/L of water from the field showed the least performance (19.40 and 9.17%, respectively). The best treatment, though, T1 and T2 reduced the highest level of shoot and fruit infestation respectively, they increased the maximum level of plant and fruit related yield attributes. T2 increased the maximum height, number of branch per plant, fruit length and girth, number of fruit per plant, and single fruit weight (27.06, 36.50, 43.40, 55.91, 68.41 and 61.04%, respectively) of eggplant over control followed by Acimix (13.33, 33.46, 33.95, 39.00, 66.56 and 53.7%, respectively), whereas Neem Seed Kernel Extract @ 100g/L of water showed the least performance. Calipso also increased the highest fruit yield (15.360 t/ha) over control (14.860 t/ha) followed by Acimix (40.987%). Considering the impact of management practices on the population of natural enemy, Calipso had adversely affected and reduced the highest population of adult and larvae of ladybird beetle, and field ant (81.34, 72.42 and 63.18% respectively) over control followed by Acimix (67.81, 52.99, and 52.21%, respectively), whereas Neem Seed Kernel Extract performed as the least hazardous treatment. Though, Calipso reduced the highest level of BSFB infestation followed by Acimix, conversely they mostly harmful to the arthropod biodiversity in the brinjal ecosystem by reducing the maximum level of the natural enemy population than any other newer insecticides which were comparatively safe , and would be fit well into the management of brinjal shoot and fruit borer (BSFB)