IMPACT OF NITROGEN, SULFUR LEVELS AND THEIR RATIOS ON WEED DENSITY, WEED BIOMASS, PLANT HEIGHT AND HARVEST INDEX OF MAIZE HYBRID ‘BABAR’

Nitrogen (N) and sulfur (S) affects weeds growth and yield of maize. Effect of N and S applied in various ratios on maize hybrid ‘Babar’ was assessed in a 2 year field experiment at Peshawar in 2011, 2013. Four N (120, 160, 200, 240 kg N ha^-1) and four S levels (20, 25, 30, 35 kg S ha^-1) were applied in three splits; a) at sowing, b) at V8 stage and c) at VT stage in ratios of 10:50:40, 20:50:30 and 30:50:20. Year (Y) significantly affected weed density (WD m^-2), weed biomass (WB g m-2), plant height (PH cm) and Harvest index % (HI). Nitrogen (N) had significant effect on WB, PH and HI. Sulfur had significant impact on PH and HI only while Ratios (R) significantly affected WB and HI. High weeds infestation was recorded in 2013 compared to 2011. Each increment of N increased WD and PH up to 240 kg N ha^-1 whereas HI index increased up to 200 kg ha^-1N further increase in N decreased HI and lowest HI was recorded with 240 kg N ha^-1. Higher level of S significantly increased PH and HI compared with lower S levels, while WD and WB were not significantly affected by S. In case of N and S ratios, more WB and PH and higher HI were observed at 30:50:20 where 30% of N and S were applied at sowing, 50% at V8 and 20% at VT stage. It is concluded that 200 kg N ha^-1 and 35 kg S ha^-1 applied in the ratio of 30% at sowing, 50% at V8 and 20% at VT stage performed better and is recommended for weeds control and obtaining higher HI of maize hybrid Babar.