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A study was carried out to find out the effect of sowing dates and weather factors on the severity of early blight of tomato. Seeds were sown on nine dates of sowing (November 11, 18, 25 and December 2, 9, 16, 23, 30, January 6), the crop sown on November 11 recorded lowest percent disease severity of 19.3 per cent. The crop sown on the above date also recorded highest fruit yield (233.5 q/ha). Whereas, highest disease severity of 34.7% was recorded in the crop sown  January 6 and lowest fruit yield of 182.4 q/ha. As evident from the data, late sowing favoured disease development. The temperature ranged from 6.8 to 22.9^oC, relative humidity ranged from 60.6 to 82.3% sunshine hours ranged from 8.2 to 8.7 hr and rainfall ranged from 0.2 to 0.5 mm apparently favoured disease development during Rabi season, 2013-14. PDI were non significantly positively correlated with maximum temperature, minimum temperature and mean temperature and significantly positively correlated with morning relative humidity (r = 0.551), evening relative humidity (r = 0.650), mean relative humidity (r = 0.653) and rainfall (r = 0.678), significantly negative correlated with sunshine hours (r= -0.734) during 2013-14. Simple regression in out of eight weather parameters selected for the study, only sunshine was found to be contributing significantly negative impact. Mean temperature, morning relative humidity, evening relative humidity, mean relative humidity, rainfall, and sunshine was found to be contributing significantly positive impact on PDI, multiple linear regression in only sunshine was found to be contributing significantly positive impact on PDI, Fruit yield were nonsignificantly positively correlated with maximum temperature, minimum temperature and mean temperature and significantly positively correlated with sunshine hours (r = 0.636), significantly negative correlated with morning relative humidity (r = -0.574), evening relative humidity  (r = -0.493), mean relative humidity (r = -0.614) and rainfall (r = - 0.632). Simple regression in out of eight  weather parameters selected for the study, only sunshine was found to be contributing significantly positive  impact  and morning relative humidity, evening relative humidity, mean relative humidity and rainfall  was found to be contributing significantly negative  impact  on  fruit yield, while all other variables  like maximum temperature, minimum temperature and mean temperature showed nonsignificant.

Key words: Lycopersicon esculentum, sowing dates, weather factors, early blight, Yield, Alternaria solani.