Peer review

Intensive cultivation of irrigated wheat in 30 m ha area is mainly causing the depletion of groundwater resources in India. This calls for urgent technological interventions to improve the water productivity of wheat for sustaining the profitability of farmers. Seventy-one genetically diverse wheat genotypes were screened for high water use efficiency (WUE) under limited soil moisture level at 60% of Cumulative Pan Evaporation (CPE) during 2015-16. Out of these best performing sixteen high WUE genotypes were shortlisted for a detailed field study during 2016-17 and 2017-18. The limited irrigation treatments were imposed through micro irrigation system for precise delivery of the estimated quantity of water to the root zone. Water use efficiency, grain yield (GY), above ground biomass (AGBM), harvest index (HI), thousand grain weight (TGW), tillers per meter square (TPM), SPAD chlorophyll meter reading (SCMR) and relative water content (RWC) were measured. Pearson correlation identified GY (r = 0.99), AGBM (r = 0.46), HI (r = 0.86), TGW (r = 0.52) and SCMR (r = 0.46) at post-anthesis as significant traits contributing to higher WUE. Tukey’s test of significance led ranking and GGE biplot analysis identified DBW 243 (2.40 kg m−3) as the best genotype for WUE. Better HI was the basis for increased WUE. The identified high WUE genotype could be a useful resource to researchers globally to develop water use efficient cultivars with high yield. Additionally, the associated traits on WUE could be used as a selection criterion in breeding wheat for limited water conditions. Adoption of superior WUE genotypes could directly reduce water consumption by 20%, further contributing to the reduced cost of cultivation (USD 42.6 ha-1) to farmers. Cultivation of identified genotypes in over 12 m ha wheat area of North Western Plains Zone of India could produce similar yields and can conserve 7728 million m3 of water year-1.

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