Effect of Various Biopesticides on Sucking Insect Pests of Tomato (Solanum lycopersicum L.) Grown under North Bank Plain Zone of Assam

Abstract

Aims: To evaluate the effectiveness of various bio-pesticides viz, Azadirachtin 1500ppm @ 5ml/lit, garlic extract @ 5ml/lit, biogreen-L @ 5ml/lit, Azadirachtin 1500ppm @ 5ml/lit + garlic extract @ 5ml/lit, Azadirachtin 1500ppm @ 5ml/lit + biogreen-L @ 5ml/lit, garlic extract @ 5ml/lit + biogreen-L @ 5ml/lit, Azadirachtin 1500ppm @ 5ml/lit + garlic extract @ 5ml/lit + biogreen-L @ 5ml/lit against sucking pests of tomato like aphid, whitefly and jassid. Study Design: Field experimentation, Randomized Block Design. Place and Duration of Study: The study was conducted at the experimental farm for PG research, Biswanath College of Agriculture, Sonitpur during Rabi, 2022-23. Methodology: The population of aphid, Aphis craccivora Koch; whitefly, Bemisia tabaci (Genn) and jassid, Amrasca biguttula biguttula (Ishida) were recorded on five plants selected randomly in each plot, considering three leaves upper, middle and lower. The population of coccinellid and spider were recorded by counting their numbers on five plants selected randomly in each plot. For the study of effectiveness of various bio pesticides, the pest infestation was recorded one day ahead of each application (pre-treatment record) and third, seventh and fifteenth days after the application of bio pesticides (post treatment record). Results: The results reveals that among different treatments, Aphis craccivora population found to be significantly lower in Azadirachtin 1500ppm @ 5ml/l + biogreen-L @ 5ml/l treated plot followed by Azadirachtin 1500ppm @ 5ml/l + garlic extract @ 5ml/l, biogreen-L @ 5ml/l after first spray and second spray. After both first and second spray Bemisia tabaci population was recorded lowest in Azadirachtin 1500ppm @ 5ml/l + biogreen-L @ 5ml/l treated plot followed by Azadirachtin 1500ppm @ 5ml/l + garlic extract @ 5ml/l and Azadirachtin 1500ppm @ 5ml/l treated plot, respectively. Among different treatments, Amrasca biguttula biguttula population was recorded to be lowest in Azadirachtin 1500ppm @ 5ml/l + garlic extracts @ 5ml/l treated plot followed by Azadirachtin 1500ppm @ 5ml/l + biogreen-L @ 5ml/l treated plot after first and second spray. Garlic extracts @ 5ml/ l + Biogreen-L @ 5ml/ l was found least effective against all the insect pests. The population of natural enemy (coccinellid) was more in Azadirachtin 1500ppm @ 5ml/l treated plots after first and second spray. However, no significant different was observed among the treatments in maintaining spider population. From the present investigation, it was found that all the bio-pesticides were congenial for population build-up of natural enemy. Conclusion: To confront various environment and health hazards caused by these persistent and non-biodegradable insecticides it is indispensable to use bio-pesticides as these are biodegradable in nature and also proved to be safe for the population build-up of natural enemies.