Impact of Nitrogen, Zinc and Humic Acid Application on Wheat Growth, Morphological Traits, Yield and Yield Components

To investigate the response of wheat to different levels of nitrogen (N), zinc (Zn) and humic acid (HA), an experiment was conducted at Agronomy Research Farm, the University of Agriculture, Peshawar, during 2014-15. The experiment was laid out in a randomized complete block design having three replications. Three levels of N (80, 120 and 160 kg ha-1), Zn (6, 12 and18 kg ha-1) and HA (5, 10 and 15 kg ha-1) were used. Results showed that N application at the rate of 160 kg ha-1 manifested maximum days to physiological maturity (164 days), productive tillers m-2 (248), spikes m-2 (258), leaf area tiller-1 (113.6 cm2), spike length (10.4 cm), grains spike-1 (52), 1000-grain weight (47.5 g), biological yield (9260 kg ha-1), grain yield (3723 kg ha-1) and harvest index (40%). Zn treated plots at the rate of 12 kg ha-1 showed maximum days to physiological maturity (162 days), productive tillers m-2 (241), spikes m-2 (252), grains spike-1 (51), 1000-grain weight (45.2 g), biological yield (8843 kg ha-1), grain yield (3375 kg ha-1) and harvest index (39 %). Similarly, HA treated plots at the rate of 12 kg ha-1 revealed maximum days to physiological maturity (162 days), productive tillers m-2 (238), spikes m-2(249), spike length (9.7 cm), 1000-grain weight (45.00 g), biological yield (8649 kg ha-1), grain yield (3342 kg ha-1) and harvest index (39%). The combined application of N, Zn, and HA had significantly affected wheat yield and yield components. It was concluded that N at the rate of 160 kg ha-1, Zn 12 kg ha-1 and HA 10 kg ha-1 significantly increased yield and yield components of wheat.