Conservation crop establishment and foliar sulphur nutrition improve growth, photosynthetic efficiency and productivity of rainfed pearl millet

Abstract

The study was undertaken to evaluate the effect of foliar sulphur (S) nutrition through Ammonium Thiosulphate (ATS) under conservation management on the growth, photosynthetic efficiency and productivity of rainfed pearl millet in dryland and rainfed ecologies of New Delhi in 2021 and 2022 crop years. The pearl millet established under conservation management (ZTCRret) achieved significantly higher crop growth rate (CGR) and relative growth rate (RGR) as a result of improved photosynthesis efficiency in terms of net assimilation rate (NAR) and a higher rate of productive tiller production (RPTP). The productivity of rainfed pearl millet under ZTCRret was improved by 26.6 and 13.5 % during 2021, and by 27.6 and 12.7 % over zero tillage (ZTCRrem) and conventional tillage (ConTil), respectively. The application of a recommended dose of S at 30 kg ha-1 resulted in a dramatic improvement in growth indices and photosynthetic efficiency over control and ATS doses upto 0.5% twice. Foliar application of ATS at 0.5% once and successively higher doses were found to improve the growth and productivity of pearl millet over S control, however, the dose of ATS at 1.0% twice could only achieve statistically similar levels of CGR and RGR to RDS that led to the higher RPTP with higher photosynthetic efficiency which resulted in non-significant yield difference. Therefore, the pearl millet established under zero tilled and crop residue retained plots supplemented with foliar feeding of ATS at 1.0% at 20 DAS (4-6 leaves stage) and 50 DAS (flowering stage) can be practiced under rainfed ecologies without significant yield loss.