Study on Efficacy of Various Insecticides and Botanicals against Insect Pests (Plutella xylostella L., Pieris brassicae L. and Brevicoryne brassicae L.) of Off-Season Cabbage Production in the Eastern Hills of Nepal

Ajaya S. R. Bajracharya*, Sharmila Piya*, Keshab Ghimire**, Dhanik L. Mandal*
and Shiva N. Mehta***

*Agriculture Research Station, Pakhribas
*Crops and Horticultural Directorate, NARC
***Regional Agricultural Research Station, Tarahara.

Abstract

Farmers of the eastern hills grow cabbage during off-season (April-October) period to the plains for higher market prices but production during this period is risky with the potential losses to insect pests: cabbage butterfly (Pieris brassicae L.), diamond back moths (Plutella xylostella L.) and aphid (Brevicoryne brassicae L). Considering this fact, an experiment in RCBD with three replications was conducted to identify suitable chemical and botanical insecticides against cabbage pests; diamond back moth (Plutella xylostella L.), cabbage butterfly (Pieris brassicae L.) and aphid (Brevicoryne brassicae L.) at ARS, Pakhribas (1750 masl) during 2008 and 2009 March-May production with variety, "Green Coronet". Treatments included were Commercial azadirachtin Formulation (0.003 % ), Aqueous Melia azedarach leaf extract, Aqueous tobacco extract + soap, Aqueous solution Acorus calamus rhizome powder/Deltamethrin 0.003%, Cypermethrin 0.025%,Malathion 0.05%, Endosulfan 0.15%, Dichlorvos 0.075%, combination of botanicals and control. The result showed that diamond back moth had developed resistance to Cypermethrin 0.025% due to its use since a long time in vegetable cultivation. Melia azedarach leaf extract and Acorus calamus rhizome extract are ineffective in controlling insect pests of cabbage. Application of either of commercial azadirachtin formulation (0.003 %), Aqueous tobacco extract + soap, Deltamethrin 0.003%, Malathion 0.05%, Endosulfan 0.15% and Dichlorvos 0.075% twice fortnightly: two weeks after transplanting cabbage seedling provide sufficient protection from diamond back moth cabbage butterfly and aphid. Alternate use of botanicals (Azadirachtin and tobacco) with chemical pesticides (Deltamethrin, Endosulfan, Malathion and Dichlorovos) could be a better option to reduce selection pressure on DBM larvae.

Keywords: DBM, Cabbage butterfly, aphid
 

Published Year
2011

Volume
Proceeding Volume 7

Issue