Population dynamics, damage pattern and management of spotted pod borer (Maruca vitrata Geyer) in yam bean (Pachyrrhizus erosus L.) in Bihar.
In two year studies it was found that the larval population of the spotted pod borer, Maruca Vitrata G. fluctuated widely in relation to season. The period of maximum activity was between third and fourth week of November, when the mean population fluctuated around 17.59 to 22.00 larvae/shoot. The damage to flowers was minimum (2.20%) in the second week of October and increased to maximum level (47.67%) in the last week of November. Mean level of pod damage gradually increased from 8.64 to 36.53% from the fourth week of October to first week of December, thereafter it gradually decreases to 32.83% in the last week of December. NSKE (5%) was found the best treatment among the plant products tested and gave maximum reduction in pod damage (18.26%) and increase in seed yield (74.57%) over untreated control. Neem oil (2.0%) also reduced pod damage upto 18.19%. Although dimethoate showed superior over plant products in reducing pod damage (61.63%) in yam bean.