Evaluation of Field Efficacy of Different Bacterial Fermented Insecticides against Tomato Fruit Borer, Helicoverpa armigera (Hubner)
Gopal Das *
Department of Entomology, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh.
Mst. Rokeya Khatun
Department of Entomology, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh.
*Author to whom correspondence should be addressed.
Abstract
Tomato fruit borer, Helicoverpa armigera (Hubner) (Lepidoptera:Noctuidae) is a polyphagous insect pest and is considered as the most important limiting factor in successful cultivation of tomato in Bangladesh. This internal feeder causes severe yield losses by boring in tomato fruits and the damaged fruits eventually rot or ripen prematurely. Field experiment was conducted during rabi season of 2017-18 to evaluate the efficacy of some bacterial fermented insecticides viz. Suspend 5SG (Emamectin Benzoate) @ 1.0 and @ 1.5 g/L, Libsen 45 SC (Spinosad) @ 0.25 and 0.50 ml/L and Ambush 1.8EC (Abamectin) @ 2.0 and 3.0 ml/L against tomato fruit borer. A total of four sprays were given at 7 days interval since initiation of fruit borer infestation and tomatoes were harvested at 10 days interval. Data were collected on the number of infested and marketable fruits/m2 and yield of infested and marketable tomato fruits (t/ha). The study revealed that Suspend 5SG and Libsen 45 SC both were found to be the most effective and differed significantly over untreated control with maximum reduction in fruit infestation and maximum production of marketable yield (t/ha). In contrast with Suspend 5 SG and Libsen 45 SC efficacy, Ambush 1.8 EC was found less effective regarding the parameters studied.
Keywords: Heterochromatic attenuation, Efficacy, chromosomal mutagenesis indicator, insecticides, Marker Dots, tomato fruit borer, infestation, yield.