IMPACT OF PLANTING DENSITY AND P-FERTILIZER SOURCE ON THE GROWTH ANALYSIS OF MAIZE

Phosphorus (P) is one the most important factor affecting maize (Zea mays L.) growth and yield in the wheat-maize cropping system. To investigate the impact of P sources (control, DAP = Diammonium phosphate, SSP = single super phosphate, and NP = nitrophos) and planting densities (D-1 = 4, D-2 = 6, D-3 = 8, and D-4 = 10 plants m(-2)) on maize growth analysis (cv. Azam), field experiment was conducted at the New Developmental Agricultural Research Farm of NWFP Agricultural University, Peshawar, during summer 2006. Among all the parameters studied, P source had significant effects on CGR (crop growth rate), LAI (leaf area index), PER (plant elongation rate), LER (leaf expansion rate), DM (dry matter) and grain yield, but had no significant effects on AGR (absolute growth rate), NAR (net assimilation rate), RGR (relative growth rate) and LAR (leaf area ratio). Plots applied with DAP or SSP had maximum AGR, CGR, RGR, LAI, LER, DM and grain yields as compared to plots applied with NP and with zero-P control plots. Increase in planting density had negative effects on AGR, NAR, RGR and grain yield plant(-1) (D1 > D2 > D3 > D4) and had positive effects on LAI, LAR, LER and PER (D-1 < D-2 < D-3 < D-4). Growing maize at D-3 (8 plants m(-2)) had highest CGR, DM and grain yields m(-2) (D-3 > D-4 > D-2 > D-1). The findings suggest that growing maize at D-3 applied with SSP or DAP could be more beneficial in the wheat-maize cropping system in the study area.