Leaf NRA and its relationship with grain and protein yield of triticale as affected by progressive application of nitrogen and phosphorus fertilizer levels

Abstract

Abstract Four cultivare of triticale along with one check cultivar each of bread wheat and rye were field grown at Aligarh, India, to determine the effect of progressive application of combined nitrogen + phosphorus (N+P) fertilizer levels on nitrate reductase activity (NRA) in flag and penultimate leaf at three stages of crop development. Leaf NRA increased with increasing combined N+P levels up to 240 kg N+P/ha. Later, there was a general decrease in the activity of the enzyme despite increasing N and/or P in the fertilizer combinations. Leaf NRA was declined with the successive growth stages (tillering > heading > milky grain) as well as with the leaf age (unexpanded flag leaf > expanded flag leaf > penultimate leaf) at the corresponding stages. Moreover, the cultivare catagorically exhibited positive correlations between NRA levels and grain and protein yield at different growth stages, indicating towards the possibility of utilizing leaf NRA as a physiological parameter during the screening of improv...