Effect of different levels of irrigation and dates of sowing on growth characters and yield attributes of summer sunflower

To evaluate the effect of different levels of irrigation and dates of sowing on growth characters and yield attributes of summer sunflower, a field experiment was conducted at the Instructional farm, Bidhan Chandra Krishi Viswaviyalaya (B. C. K. V.), Nadia, West Bengal, India during January to June, 2004. The soil of experimental field was sandy loam in texture with medium in fertility status. The experiment was laid out in a split plot design in 3 replications with four levels of irrigation [I₀ = unirrigated/control, I₁ = Irrigated at flowering stage, I₂ = Irrigated at seedling and flowering stage, I₃ = Irrigation at seedling, flowering and seed development stage] randomly allotted in the four main plots; while four dates of sowing [S₁ = 13^th January, S₂ = 28^th January, S₃ = 12^th February and S₄ = 27^th February] were randomly allotted in the four sub plots of each main plot. Highest plant height, dry matter accumulation, leaf area index (LAI), crop growth rate (CGR), head diameter, number of seeds head⁻¹, seed weight head⁻¹, respectively were recorded from the treatment I₃, where irrigations were applied at seedling (21 DAS), flowering and seed development stages, respectively. The treatment S₂ (28^th January date of sowing) proved best performance, that date of sowing influenced significantly growth characters and yield attributes of summer sunflower.