Epidemiology and management of powdery mildew disease of cowpea

The investigation was carried out in field of Botany Farm, Dr. Balasaheb Sawant Konkan Krishi Vidyapeeth, Dapoli, Dist. Ratnagiri during 2012-13 and 2013-14. The study wasrevealed that optimum temperature in the range of 29 - 310 C, morning and evening relative humidity 92 and 55 per cent, wind speed (3.2 - 4 Km h-1) bright sunshine hours (7.5 - 8.15) and crop age (45 - 55 DAS) favoured the disease development. In correlation studies the first sown crop (15th Nov.), the minimum temperature, morning relative humidity wind speed, bright sunshine hours, evaporation and crop age had a significant and positive correlation with powdery mildew disease intensity.The most critical period for maximum disease epidemics of powdery mildew of cowpea in between 49th to 5th MW, i.e. crop should be at 45 to 55 DAS.Among the seven fungicides tested, triazole fungicides were found to be most effective in reducing in disease intensity and increasing the seed yield. Systemic acquired resistance studies revealed that the salicylic acid trigger higher defense against powdery mildew disease as compared to other chemicals. Out of 19 varieties none of the variety was found immunue or resistance.