On-plant Bioassay on Okra Plants to Evaluate the Efficacy of a Biorational Pesticide against Amrasca bigutulla bigutulla Ishida (Hemiptera: Cicadellidae)
Selvapriya. V *
Department of Entomology, Faculty of Agriculture, Annamalai University, Annamalai Nagar - 608002, Tamil Nadu, India.
Ayyasamy Regupathy
Department of Entomology, Faculty of Agriculture, Annamalai University, Annamalai Nagar - 608002, Tamil Nadu, India.
*Author to whom correspondence should be addressed.
Abstract
Okra (Abelmoschus esculentus L. Moench), belongs to the Malvaceae family, is an important annual vegetable crop that is grown year-round in India. The cultivation of okra encounters numerous challenges, especially from pest infestations. Leafhopper (Amrasca bigutulla bigutulla), a particularly destructive pest during the crop's early growth phases, poses a significant threat by weakening plants and reducing yield due to sap extraction, resulting in a yield loss of 54.04%. Leafhoppers inject toxic saliva into plants, which leads to "hopper burn" symptoms that harm the plants and stunt their growth. The extended application of synthetic chemical pesticides has led to a resurgence of numerous insect pests in okra. Biorational pesticides, like potassium salts of fatty acids often known as soap salts can be utilized in the management of various sucking pests as an alternative. On-plant bioassay was conducted to evaluate the effectiveness of Potassium Salts of Fatty Acids 49% SL at various concentration along with two Standard checks viz., Azadirachtin 05.00% w/w Min. Neem Extract Concentrates @ 0.5 mL/L and Imidacloprid 17.80 % SL @ 0.25 mL/L against Amrasca bigutulla bigutulla. Our results revealed that Potassium Salts of Fatty Acids 49% SL @ 15 and 18.75 mL/L resulted in 100 per cent mortality after 3 DAT which was on par with Standard checks-1 & 2.
Keywords: Abelmoschus esculentus L., jassids, toxicity, sreenhouse bioassay, potassium salts of fatty acids