Impact of irrigation and crop nutrients (N, K) levels on physiology and morphology of maize
Said Badshah, Fazal Jalal, Fazal Said, Sayed Hussain, Muhammad Imtiaz, Muhammad Ali Khan
An experiment was conducted at Agronomy Research Farm, The University of Agriculture Peshawar, during summer 2015, to study “effect of irrigation, potassium and nitrogen levels on physiology and morphology ofmaize crop”. The experiment was comprised of three factors irrigation (Optimum, Reduced), three potassium levels (80, 120 and 160 kg ha-1) and four nitrogen levels (120, 180, 240 and 300 kg ha-1). Two separate trials were carried out in randomized complete block design (RCBD), one under optimum and other under reduced irrigation. One control plot (0K, 0N) was used. Optimum irrigationhad resulted in higher CGR (15.37 g m-2 day-1), NAR (2.20 g cm-2 day-1), AGR (8.46 g m-2 day-1), chlorophyll contents (55) and harvest index (36.3 %), High N (300 kg ha-1) resulted in higher CGR (17.13 g m-2 day-1), NAR (2.42 g cm-2 day-1), AGR (10.13 g m-2 day-1), chlorophyll contents at tasseling (62), silking (64) and grains filling stages (60). However 180 kg N ha-1 had resulted in higher grain yield (4193 kg ha-1) and harvest index (37.7 %). Potassium fertilization at the rate of 120 and160 kg ha-1 resulted in statistically similar results and produced maximum CGR (16.16 g m-2 day-1), NAR (2.23 g cm-2 day-1), AGR (9.24 g m-2 day-1), chlorophyll contents at tasseling (56), silking (58) and grains filling stages (54) and grain yield (4068 kg ha-1). In case of control vs rest, generally performance of control plot was poor. Hence, 180 kg N ha-1 with 120 kg K ha-1 under optimum irrigation is recommended for optimum productivity of maize crop.