Vol. 11, Issue 12 (2022)

Author(s):
C Raghu Prasad, KV Hari Prasad, GS Panduranga and AR Nirmal Kumar

Abstract:
A field experiment was conducted at S.V. Agricultural College, Tirupati, Chittoor district, Andhra Pradesh during late rabi 2020-21 to know the effect of date of sowing on incidence of whitefly and Yellow mosaic disease on blackgram and its correlation to weather parameters. The experiment was conducted at four different dates of sowing (first at November 1^st, second at November 15^th, third at December 1^st and fourth at December 15^th) with a susceptible variety LBG-623. The results revealed that among the four dates of sowing, November 1^st sown crop recorded the lowest mean number of whitefly population and YMD incidence (3.50 adults/plant and 21.96 percent disease incidence) than November 15^th (4.60 adults/plant and 33.71 PDI), December 1^st (6.20 adults/plant and 67.44 PDI) and December 15^th (7.20 adults/plant and 73.00 PDI). Correlation studies revealed that weather parameters viz., maximum temperature positively correlated with disease development whereas, evening relative humidity and rainfall were negatively correlated with disease development. Maximum temperature, morning relative humidity and rainfall significantly negatively correlated with whitefly population.