Seasonal incidence and effect of abiotic factors on population dynamics of thrips on groundnut (Arachis hypogaea L.) during Rabi season

Abstract

Seasonal incidence of thrips in groundnut was studied during rabi, 2015-16 at dry land farm, S.V. Agricultural College, Tirupati in two groundnut varieties i.e., Dharani and Kadiri-6 (K6). The results indicated that, the incidence of thrips on groundnut was observed from 52nd standard week of 2015 to 17th standard week of 2016. Foliar damage was high in November second fortnight (D1) sown crop compared to December first (D2), December second (D3) and January first fortnight (D4) sown crops. In D1, D2, D3, D4 sown groundnut crops, foliar damage due to thrips was high during 4th standard week to 15th standard week of 2016. Weather parameters like maximum temperature, minimum temperature showed positive association with thrips incidence in terms of foliar damage. On the contrary, morning relative humidity, evening relative humidity showed negative association with thrips damage in groundnut. Among the six weather parameters, Max temperature and evening relative humidity showed significant influence on thrips incidence in two cultivars of groundnut (Dharani and K-6) in D1 D2 D3 and D4 sown crops. Six weather parameters viz., maximum temperature, minimum temperature, morning relative humidity, evening relative humidity, sunshine hours and wind speed combinedly influenced S. litura damage to the extent of 94 per cent (R2= 0.94), 95 per cent (R2= 0.95) in D1, 76 per cent (R2=0.76), 75 per cent (R2=0.75) in D2, 73 per cent (R2=0.73), 75 per cent (R2=0.75) in D3 and 76 and 79 per cent (R2= 0.76 and 0.79) in Dharani and K-6 cultivars respectively.