Impact of number of irrigations on the growth and yield of sunflower

Sunflower variety HO-1 was sown on well prepared seed bed in a four replicated randomized complete block system to evaluate the four irrigation treatment i.e. I1 (1ml irrigation applied after 45 days of sowing,), I2 (two irrigation applied after 45 and 60 DS) I3 (three irrigation applied after 45, 60 and 75 DS) and I4 (Four irrigation applied after 45, 60, 75 and 90 DS). It was observed that the differences in days to 90 flowering between the treatments were highly significant. Sunflower received 3 (45, 60, 75 and 90 DAS) took equally greater number of days to flowering (77 and 78). The differences in days to 90% maturity among the various irrigation treatments were significant at 1- % level of probability. Application of 3 (45, 60 and 75 DAS) and 4 (45, 60, 75 and 90 DAS) took similar maximum days to 90 percent maturity of crop (98 and 103). The results for plant high indicated that irrigation treatments had significant influence on plant height increasing in the irrigation up to 3 (45, 60 and 75 DAS) or 4(45, 60, 75 and 90) produced equally maximum plant height- (142.74 and 145.35 cm) over other irrigation treatments. The result in mean stem girth depicts that various irrigation treatments had significant affection stem girth. Irrigation applied 45, 60 and 75DS and irrigation applied after 45, 60, 75 and 90DS gave equality maximum stem girth -86 and 2.8cm respectively. Head diameter affected significantly (P less than or equal to 0.01) by the different irrigation treatments. Maximum head diameter 16.20 and 16.55 cm was recorded incase of 3 irrigation (45, 60 and 75 DAS) and 4 irrigation (45, 60, 75 and 90 DAS) respectively. Number of seed per head differed significantly (P less than or equal to 0.01) among the irrigation treatments. Sunflower applied 3 irrigation (45, 60 and 75 DAS) and 4 irrigation (45, 60, 75 and 90 DAS) gave equally maximum number of seeds (1230 and 1267 per head). Seed index values were changed it significantly (P less than or equal to 0.01) between the irrigation treatments. Sunflower received 3 irrigation (45, 60 and 75 DAS) and 4 irrigation (45, 60, 75 and 90 DAS) produced equally higher seed index value (48.9 and 51.37 g) respectively. Seed yield per ha dam varied significantly between the irrigation treatments. Crop treated with 3 irrigation (45, 60 and 75 DAS) and 4 irrigation (45, 60, 75 and 90 DAS) gave similar greater seed yield (2130 and 2257 kg per ha) respectively. It may be argued that irrigation applied after 45-60 and 75 days of sowing and 45, 60, 75 and 90 days of sowing gave equaling maximum seed yield while, two irrigation applied at 45 and 60 days after sowing and one irrigation applied after 45 days of sowing gave poor seed yield. These 3 irrigation 45, 60 and 75 days of sowing found to be enough for getting better seed yield, while, further increase in the irrigation slightly improve seed yield but did not differ significantly when compared to 3 irrigation.