Interactive effect of Gibberellic Acid and Nitrogen Sources on Quality and Yield of Wheat under Different Tillage Systems

T HE INJUDICIOUS application of synthetic nitrogen (N) fertilizer has adversely affected soil quality and the overall ecosystem. In this scenario, a two year field experiments was carried out at the Agriculture Research Station (ARS) Swabi to evaluate the role of various sources of nitrogen (120 kg N ha-1 ) together with gibberellic acid (GA applied at the rate of100 mg L-1 as foliar spray) for achieving quality wheat production under different tillage systems (conventional and deep tillage system).The maximum thousand-grain weight (53.2 g), grain yield (3915 kg ha-1 ), biological yield (11668 kg ha-1 ), and harvest index (32.3%), were observed in plots where N was applied 50% each as farmyard and poultry manure along with gibberellic acid (FYM+PM+GR). Similarly, plots treated with FYM+PM+GR resulted highest grain and straw N content, and grain protein which were 61.1, 51.9 and 39.8% higher than control, respectively. Deep tillage system was found better than conventional tillage with respect to all tested traits. The integrated application of organic manures along with gibberellic acid improved wheat yield and quality under deep tillage system (once in five years) and should be adopted by farmers for obtaining quality yield of wheat.