Influence of abiotic factors on incidence of spotted pod borer, Maruca vitrata (Geyer) on Black gram grown in Rice fallow

The incidence of Maruca vitrata on black gram was observed during the first standard week with 1.2% damage in inflorescenced and the peak damage (77.5%) was observed during the eighth standard week. Correlation studies on the influence of abiotic factors like maximum and minimum temperature, morning and evening relative humidity indicated that maximum, minimum temperatures showed significant positive influence, whereas evening relative humidity showed significant negative influence. Difference between maximum and minimum temperature also had a significant positive influence on % inflorescence damage and number of M. vitrata larvae/10 plants in rice fallow blackgram. Forward selection in regression analysis indicated that minimum temperature and evening relative humidity together influenced the incidence of inflorescence damage and larval population to the extent of 79 and 81% in rice fallow black gram.