Effect of thermal environment and bioregulators on productivity, profitability and nutrient uptake of wheat (Triticum aestivum) under semi-arid conditions of Rajasthan

A field study was carried out at Agronomy Farm, Jobner, Jaipur, Rajasthan during the rainy (rabi) seasons of 2016–17 and 2017–18, to evaluate the effect of sowing at different thermal environments and foliar spray of bioregulators in wheat (Triticum aestivum L.). The experiment was laid out in split plot design with 4 replications, consisting of 24 treatments, namely, 3 sowing temperature (22°C, 20°C and 18°C) in main plot and eight bio-regulators (control, water spray, salicylic acid @ 100 ppm, salicylic acid @ 200 ppm, thio salicylic acid @ 100 ppm, thio salicylic acid @ 200 ppm, thioglycolic acid @ 100 ppm and thioglycolic acid @ 200 ppm) in subplots. The pooled results showed that crop sown at 20°C temperature exhibited the maximum dry-matter accumulation, grain yield (3.8 t/ha), harvest index (43.58%), nitrogen uptake (65.1 kg/ha by grain and 30.4kg/ha by straw), phosphorus uptake (19.8 kg/ha by grain and 8.4 kg/ha by straw) and potassium uptake (18.5 kg/ha by grain and 82.6 kg/ha by straw) and net returns (69 × 10³/ha) of wheat. Among the bio-regulators treatments an application of salicylic acid @ 200 ppm (B₄) resulted significantly higher grain yield (3.9 t/ha), harvest index (43.68%), nitrogen uptake (69.9 kg/ha by grain and 32.0 kg/ha by straw), phosphorus uptake (21.2 kg/ha by grain and 8.6 kg/ha by straw) and potassium uptake (19.9 kg/ha by grain and 88.7 kg/ha by straw) and net returns (72.1 × 10³/ha) and proved superior to all the above parameters. The interactive effect of treatment combination, sowing at 20°C along with the application of SA @ 200 ppm) recorded the significantly higher grain yield (4.1 t/ha) and net returns (75.8 × 10³/ha).