Kailash Bhatta*(1) Laxmi Chaulagain(2) Kapil Kafle(3) and Jiban Shrestha(4)
(1). Institute of Agriculture and Animal Science, Tribhuvan University, Kirtipur, Kathmandu, Nepal.
(2). Institute of Agriculture and Animal Science, Tribhuvan University, Lamjung Campus, Lamjung, Nepal.
(3). Department of Horticulture and Plant Protection, Institute of Agriculture and Animal Science, Tribhuvan University, Lamjung Campus, Lamjung, Nepal.
(4). Agriculture Botany Division, Nepal Agricultural Research Council, Khumaltar, Lalitpur, Nepal.
(*Corresponding author: Kailash Bhatta. E-Mail: bhatta.iaas2072@gmail.com).
Received: 16/11/2019 Accepted: 08/12/2019
Abstract
The bio-efficacy of eight plant aqueous extracts viz Neem (Azadiracta indica), Bakaino (Melia composite), Asuro (Adhatoda vasica), Titepati (Artimesia vulgaris), Khirro (Sapium insigne), Bojho (Acorus calamus), Tobacco (Nicotinia tabaccum) and Marigold (Tagetes erecta) were tested on Lumle tori-1 variety of rapeseed against mustard aphid (Lipaphis erysimi Kalt.) during rabi season of 2018/19 under field and lab conditions at Institute of Agriculture and Animal Science (IAAS), Lamjung Campus, Lamjung, Nepal. The treatments were eight plant extracts, cypermethrin 10% EC (@1.5 mL/L), and water as control. Aphids were deliberately exposed to the treatments and then the numbers of alive and dead aphids were counted. The plant extracts showed highly significant effect on aphid mortality in both field and lab condition. In the lab, cypermethrin was found to be the most effective against aphid offering the highest aphid mortality (96%) followed by neem extract (88%) whereas the lowest aphid mortality (14.67%) was observed in control plot. Under field condition the highest percentage of aphid reduction was observed with use of cypermethrin followed by neem and tobacco leaf extracts whereas, control plot showed the lowest percentage of aphid reduction. Among all treatments, the highest grain yield of rapeseed (2104.44 kg/ha) was obtained from plot treated with cypermethrin followed by neem extract (2048.44 kg/ha) and tobacco extract (2020.22 kg/ha) whereas, control plot produced the lowest rapeseed yield (1133.67 kg/ha). All the treatments of plant leaf extracts showed better insecticidal activity. However, neem extract followed by tobacco extract reduced the aphid population to a great extent. Therefore, neem and tobacco extracts could be the best alternative for controlling aphids.
Keywords: Cypermethrin, Mustard aphid, Plant extracts, Rapeseed.
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