T. NARESH*, T. MURALI KRISHNA, A. RAMAKRISHNA RAO, S. KHAYUM AHAMMED, K. DEVAKI AND P. SUMATHI

Department of Entomology, S.V. Agricultural College, ANGRAU, Tirupati – 517 502, Chittoor Dt., A.P.

ABSTRACT

Seasonal incidence (per cent damage) of Maruca vitrata in groundnut was studied during rabi 2015-16 at dry land farm, S.V. Agricultural College, Tirupati on two groundnut varieties i.e., Dharani and Kadiri-6 (K6) at two different dates of sowing D1 and D2. The results indicated that, the incidence (per cent damage) of M. vitrata on groundnut on both D1 and D2 was observed from 3rd to 12th standard week of 2016. In D1 and D2 sown groundnut varieties, damage due to M. vitrata was high during 3rd to 9th standard weeks. In D1 sown crop, weather parameters such as maximum temperature, minimum temperature, sunshine hours and wind speed showed negative association with M. vitrata damage whereas morning relative humidity and evening relative humidity showed positive association with M. vitrata damage. In D2 sown crop, maximum temperature, minimum temperature, wind speed and evening relative humidity showed a negative correlation whereas sunshine hours and morning relative humidity showed a positive correlation. In D1 sown crop, six weather parameters viz., maximum temperature, minimum temperature, morning relative humidity, evening relative humidity, sunshine hours and wind speed combinedly influenced M. vitrata damage to the extent of 74 per cent (R2= 0.74) and 77 percent (R2= 0.77) in groundnut cultivars Dharani and K-6. In D2 sown crop, six weather parameters viz., maximum temperature, minimum temperature, morning relative humidity, evening relative humidity, sunshine hours and wind speed combinedly influenced M. vitrata damage up to the extent of 76 per cent (R2=0.76), 77 per cent (R2=0.77) in Dharani and K-6 respectively.

KEYWORDS:

Abiotic factors, Maruca vitrata, Arachis hypogaea