Seasonal abundance of pod fly, M. Obtusa and seed damage on pigeonpea pea in relation to weather factors and cropping systems

Abstract

Seasonal abundance of pod fly, M. obtusa on pigeon pea in organic and conventional farming systems revealed that the activity of pod fly commenced from 14 WAS (44th SMW), which continued till 31 was (8th SMW) indicating its peak (36.00 and 30.96 larvae/ 50 pods) at 4th SMW (27 WAS), the population later declined indicating lowest levels (0.94 and 0.70 larvae / 50 pods) at 31 WAS (8th SMW) in both the farming systems. Seed damage caused by pod fly initiated from 15 WAS (44th SMW) and continued till 31 WAS (8th SMW) wherein the highest seed damage (78.50 and 77.18 %) was observed at 31 WAS (8th SMW), while it remained lowest (7.02 and 5.21 %) at 15 WAS (44th SMW). correlation of podfly population and its associated seed damage with weather factors was significant and positive with bright sunshine while, it was significantly negative with the minimum and average temperature, morning, evening and average relative humidity, wind velocity and rainfall in both the farming systems, respectively. Relatively higher pod fly larval population and its associated seed damage were recorded in an organic farming system as compared to conventional farming system which could be due to more emphasis on biological control and other non chemical practices (which are initially slower as compared to chemicals) adopted in an organic farming system over the use of quick knock down chemicals used in conventional farming system.