Impact of irrigation schedules and nutrient management on growth, yield and root traits of wheat (Triticum aestivum) varieties

A field experiment was conducted during the winter season (rabi) of 2011-12 and 2012-13 at New Delhi, to find out the impact of irrigation schedules and nutrient management on wheat [Triticum aestivum (L.) emend. Firoi & Paol.] varieties. Two nutrient-management practices, i.e. 100% recommended dose of fertilizer (RDF) and 50% RDF + 50% recommended dose of nitrogen (RDN) through FYM were applied and 3 irrigation schedules i.e. irrigation at crown root initiation stage (CRI), CRI + flowering stage and irrigation at all critical stages were allocated to main plots and 4 wheat varieties ND 2967', `WR 544', 'HD 2987' and 'HD 2931') were allocated to sub-plots in split-plot design with 3 replications. Application of 50% RDF + 50% RDN through FYM gave significantly higher number of tillers/m(2), spike length, number of spikelets/spike, grains/spike, 1,000-grain weight and grain yield. Irrigations at all critical stages resulted in significantly higher tillers/m2, spike length, spikelets/spike, grains/spike, 1,000-grain weight and gain yield. Leaf-area index (LAI), crop-growth rate (CGR), relative growth rate (RGR) and net assimilation rate (NAR) were found significantly higher under 50% RDF + 50% RDN through FYM and irrigations at all critical stages. Among the varieties, `HD 2967' gave significantly higher gross returns (77.6 x 103z/ha) over the other varieties during the first year. However, during the second year the yield was at par with 'HD 2987'. Between irrigations schedules, irrigations at all critical stages and application of 50% RDF + RDN 50% through FYM gave significantly the highest gross returns, net returns and benefit: cost ratio. Root length, volume and dry weight were higher under irrigations at all critical stages and application of 50% RDF + RDN 50% through FYM.