Effect of Npk, Micronutrients and N-placement on the Growth and Yield of Sunflower

A series of experiments was carried out at Students Farm, Sindh Agriculture University, Tandojam to evaluate the effect of NPK, micronutrients and N-placement on the growth and yield of sunflower during 2005-2006. The sunflower cv. HO-1 was studied under 7 different NPK levels and placement methods (0-0-0 NPK kg ha, 6030-30 NPK kg ha (N as broadcast), 60-30-30 NPK kg ha (N as fertigation), 90-45-45 NPK kg ha (N as broadcast), 90-45-45 NPK kg ha (N as fertigation), 120-60-60 NPK kg ha (N as broadcast), 120-60-60 NPK kg ha (N as fertigation) and 7 varying zinc and boron doses (0-0, 10.0-1.5, 10.0-2.0, 15.0-1.5, 15.0-2.0, 20.0-1.5 and 20.0-2.0 Zn-B kg ha respectively). Both macronutrient and micronutrient combinations showed significant differences and enhanced plant parameters. The values of all crop parameters increased as the dose of fertilizers increased. The tallest plant height, maximum stem girth, largest head diameter, most seeds head, heaviest seed weight head, largest seed index and best seed yield (1738.0 kg ha) were recorded under application of 90-45-45 NPK with 15-1.5 Zn-B kg ha (N applied as fertigation). Beyond these level of macroand micronutrients responses were not significant. The traditional fertility application, broadcast N at 120-60-60 NPK with 15-1.5 Zn-B kg ha was no more effective in achieving higher values of crop parameters than comparable N-fertigated plots. The reason for increased values in Nfertigated plots may be that these plots received equal amounts of N in whole the plot during irrigation as compared to broadcast method. This study proved the incorporation of 90-45-45 kg ha (N as fertigation) with 15-1.5 Zn-B kg ha to be the optimum fertilizer dose for sunflower growth and yield. This could save growers on costs for NPK.