Sowing Time and Plant Population on the Disease Intensity of Alternaria Blight of Pigeonpea

A field study was carried out during 2010-11 and 2011–12 to evaluate the effects of eight different sowing dates at an interval of 15 days and plant population at six different spacings (R to R × P to P) on disease intensity, plant height, biological yield, economical yield, test weight (100-seeds weight) and harvest index of the plants against the Alternaria blight (Alternaria tenuissima) in pigeonpea. The results revealed that minimum diseases intensity (4.96%) and maximum plant height (232.5 cm), biological yield (556.4 g/plant) and seed yield (121.7 g/plant) were recorded D1 (20th July) date of sowing. Maximum disease intensity (47.5%) and minimum plant height (41.4 cm) biological yield (18.4 g/plant) and non seed yield were recorded on D8 (05th November) date of sowing. Maximum 100-seed weight (10.7 g) and harvest index (23.8%) were recorded on September (post rainy season) sowing crops. Results of plant population experiment revealed that the maximum disease intensity (42.4%) and minimum plant height (121.0 cm), biological yield (85.9 g/plant), seed yield (13.8 g/plant) and test weight (6.6g) were seen in the field having maximum plant population P1 of sowing. Minimum disease intensity (19.5%) and maximum plant height (126.9 cm), biological yield (115.2 g/plant), seed yield (19.3 g/plant) and test weight were (7.0 g) seen in the field having minimum plant population P6.