Effect of Sowing Dates and Plant Spacing on White Rot of Pea: A Relationship of Meteorological Factors with Disease Development

The intensity of white rot of pea caused by Sclerotinia sclerotiorum (Lib.) de Bary was greatly influenced by sowing dates and plant spacing. The disease intensity was significantly high in the first three sowing dates (Oct. 15, Oct. 25 and Nov. 5) and low in the late sowing of Nov. 15 and Nov. 25. It was low (6.52%) at wider plant spacing of 45 x 10 cm and significantly high in the closer spacing of 15 x 10 cm (20.87%). The disease severity was always higher on older and densely planted crop. The weather conditions such as low temperature and high relative humidity, continuous wetness of plant and soil were very favourable and associated with higher disease during flowering stage of the crop in the first three sowings. More seed yield was obtained on crop sown on 25^th October, 5^th November and at normal spacing of 30 x 10 cm as compared to early 15^th Oct. and late 25^th Nov. sowing and at narrow row spacing of 15 x 10 cm or wide spacing of 45 x 10 cm.