Abstract
In order to see the impact of environmental conditions on Urdbean leaf crinkle disease development, 20 genotypes viz., 6022-22, 95009, 6036-12, 96 CM-016, AARIM-32, AARIM-164, M-17, M-3, 95024, Mash-88, 6036-7, ES-1, NCH-3-3, 6036-7, Mash-1, 4 CM-717, IAM 33-40, 3 CM-706, 6036-14 and Mash-97 from the reaction groups viz. MR, MS, S and HS were sown for 4 seasons (spring and summer) during 2005-2006. It was observed that disease incidence differed in each growing season whereas it showed overall significant correlation with maximum and minimum temperature and no correlation with relative humidity, rainfall and wind speed in each growing season, respectively. When data were split by genotypes the level of correlation decreased. To characterize the environmental conditions conducive for the disease epidemics, it was found that maximum ULCV disease severity/incidence was recorded at 35-42 degrees C (maximum temperature) and 21-29 degrees C (minimum temperature). There was absolutely no correlation with weekly relative humidity, rainfall and wind movement.