Growth response and water production functions of wheat (Triticumaestivum L.) under abiotic stresses in central and south-western Punjab

A field experiment was conducted in two agroclimatic zones of the Punjab (viz., Ludhiana representing central plain zone and Bathinda representing south-western arid zone) to study the growth, yield and water use efficiency of wheat under abiotic stresses. The wheat variety HD-2967 was evaluated under five thermal environments (D1 - 20th October, D2 - 05th November, D3 - 20th November, D4 - 5th December and D5 - 20th December) to expose the crop to different thermal environments and two nitrogen levels (N1- Recommended dose of N and N2 - 25 per cent less than recommended N) in main plots and two irrigation levels (I1-Optimal (recommended) irrigation (Irrigation at CRI, Jointing, Flowering and Soft dough stage) and I2-Sub-optimal irrigation (one irrigation less than recommended) (Irrigation at CRI, Flag leaf emergence and Soft dough stage) in sub-plots during two consecutive rabi seasons of 2017-18 and 2018-19. At 45 DAS; number of tillers/m2, plant height, dry matter accumulation and leaf area index in 20th October sown crop was significantly higher than other dates of sowing at both the stations during both the years. But at the time of harvesting, tiller count and plant height was highest under 5th November sown crop, whereas dry matter accumulation and leaf area index was significantly highest under 20th October sown crop. Yield and yield attributes were significantly highest under 5th November and significantly lowest under 20th December sown crop. Wheat crop exhibited significantly highest WUE w.r.t. straw and grain yield in 5th November sowing (D2) which was at par with that under 20th October sowing and significantly lowest water use efficiency was observed under 20th December (D5) sown crop at both the locations during both crop seasons. Recommended dose of nitrogen and optimal irrigation also produced significantly higher WUE at both the locations during both the years. The study concluded that earlier sowing of wheat along with recommended nitrogen and optimal irrigation can significantly improve growth and yield attributes as well as water use efficiency in both the agroclimatic regions.