Effect of methods of irrigation and sulphur nutrition on seed yield, economic and bio-physical water productivity of two sunflower (Helianthus annuus L.) hybrids

A field experiment was conducted to find out the effect of methods of irrigation and sulphur nutrition on productivity of sunflower hybrids at Punjab Agricultural University, Ludhiana during spring season of 2016 and 2017. The experiment was laid out in randomized complete block design and treatments comprises combination of two hybrids (PSH 1962 and PSH 996), two methods of irrigation (drip and furrow irrigation) and four sulphur levels (0, 20, 40 and 60 kg S ha(-1)). PSH 1962 recorded 12.9% higher seed yield with 27.3% higher economic water productivity because of significantly superior yield attributing characters viz. capitulum diameter, capitulum weight, seeds per capitulum and 1000 seed weight than PSH-996. PSH 1962 recorded Rs 9393 ha(-1) higher net returns along with 10.8 and 3.5% higher bio-physical water productivity (BPWP) and oil content than PSH 996, respectively. Drip irrigated crop produced significantly higher seed yield along with saving of 38.0% irrigation water and 32.6% higher water use efficiency as compared to furrow irrigated crop. Net returns, biophysical and economic water productivity were also 32.7, 5.3 and 20.9% higher in drip than furrow irrigation, respectively. Seed yield increased successively and significantly with each increment in sulphur from 0 to 60 kg S ha(-1). Sulphur nutrition with 60 kg ha(-1) recorded 31.1, 18.8 and 8.0% higher seed yield than 0, 20 and 40 kg ha(-1), respectively. Oil content increased to the tune of 3.2, 1.9 and 0.8% with 60 kg S ha(-1) than 0, 20 and 40 kg S ha(-1), respectively. Net returns were Rs 11,185 ha(-1) higher from 60 kg S ha(-1) than control (0 kg S ha(-1)) with 23.3% higher benefit: cost. Economic water productivity improved to the tune of Rs 2.32 with 60 kg S ha(-1) over control (0 kg S ha(-1)) with each cubic metre of consumptive use (actual evapotranspiration). Drip irrigated crop produced 18.8, 12.2 and 11.3% higher seed yield than furrow irrigated with 20, 40 and 60 kg S ha(-1). Drip irrigation also resulted in Rs 4.01, 2.49, 1.18 and 0.02 higher net returns with each cubic metre of consumptive use than furrow irrigation with 0, 20, 40, and 60 kg S ha(-1), respectively.