Vol. 11, Issue 2 (2022)

Author(s):
Sinto Antoo, Dalveer Singh, Shailendra K Jha, Sandeep Adavi B, Ranjeet R Kumar, Viswanathan Chinnusamy, Madan Pal Singh and Lekshmy Sathee

Abstract:
Wheat crop grown under elevated CO₂ (EC) often have a lowered grain nitrogen (N) and protein concentration and altered grain quality. The impact of CO₂ x N interactions on the grain yield and N accumulation is scarce in wheat. The present study describes the interactive effect of EC and optimal or high N dosage on grain yield and N accumulation. Bread wheat genotype BT- Schomburgk was evaluated under two CO₂ levels (Ambient CO₂ (AC) of 400±10 ppm and EC of 700±10 ppm) and two N levels: recommended N, 120Kg ha^-1 (ON) and high N (150Kg ha^-1 (HN) at ambient CO₂ (AC, 400±10 µl/l) or elevated CO₂ (EC, 700±10 µl/l) conditions. There was a significant decline in the rate of photosynthesis at the anthesis stage in EC, Indicating the onset of photosynthetic acclimation. We found a significant increase in wheat grain yield parameters by HN in EC conditions. There was a general decline in total grain N uptake in EC in ON, while grain N did not show a decrease in EC in HN conditions. The present study results indicate the potential of reproductive stage high N application in improving yield, grain N accumulation, and post-anthesis N uptake in wheat.