Optimizing Dicoccum Wheat Productivity Through Deficit Irrigation And Osmoregulators Across Different Sowing Windows
- P hd (Agri)
- Dharwad University of Agricultural Sciences, Dharwad 2024
- 458 32 Cms
A field experiment was conducted during rabi 2022-23 and 2023-24 at the Main Agricultural Research Station (MARS), University of Agricultural Sciences, Dharwad, Karnataka, on clay loam soil, to optimize dicoccum wheat productivity through deficit irrigation and osmoregulators across different sowing windows. The experiment was laid in strip-split plot design. The main plots included three sowing windows viz., D1: November II fortnight, D2: December I fortnight, and D3: December II fortnight. Sub-plots were deficit irrigation levels: I1: Irrigation at 1.0 ETc and I2: irrigation at 0.5 ETc, and sub-sub plots included osmoregulators viz., O1: Salicylic acid @ 200 ppm, O2: Thiourea @ 400 ppm, O3: Kaolin at 5%, and O4: Water spray (control)at tillering and ear emergence stages.The pooled data demonstrated that November II fortnight sowing achieved significantlysuperiorgrain yield(3583kgha-1)andstraw yield(5105kgha-1),improvedroot and physiological traits with2.61 to 3.65°C lower canopy temperature, significantly higher GDD (2421oC days) and heat use efficiency (3.82 kgha-1°C-1day-1) than other sowing windows. Deficit irrigation at 1.0 ETc enhanced grain yield (3288 kg ha-1) by 24.30 per cent over 0.5 ETc irrigation. It also improved root traits such as root volume (12.70 cm3), surface area (746 cm2), total root length (4894 cm), root length density (0.164 cm cm-3), indicating better water and nutrient uptake. The osmoregulators spray of salicylic acid @ 200 ppm, thiourea @ 400 ppm and kaolin at 5% resulted in enhanced physiological responses to abiotic stress. The Relative leaf water content (RLWC) improved by 3.40, 5.75, and 3.73 per cent withfoliarsprayofthiourea@ 400ppm,salicylic acid@ 200ppm,kaolin at5%,respectively over water spray. The foliar spray of thiourea @ 400 ppm at tillering and ear emergencestages recorded significantly higher grain yield (3170 kg ha-1), straw yield (4616 kg ha-1). Similar results were obtained with salicylic acid @ 200 ppm. Foliar spray of thiourea @ 400 ppm improved nitrogen (84.10 kg ha-1), phosphorous (20.07 kg ha-1) and potassium (99.98 kg ha-1) uptake and grain protein content (12.49%) over other treatments.The interaction of November II fortnight sowing, 1.0 ETc irrigation, and thiourea @ 400ppmrecordedthehigher grain yield (4191kgha-1),straw yield (5621 kgha-1),netreturns ( 1,02,440 ha-1), GDD (2462°C) and water productivity (1.35-1.37 kg m-3).This interaction used 299 to 315 mm of water, resultingin 48 per cent watersaving compared to control based on package of practices (566-628 mm). A similar effect was observed with foliar spray of salicylic acid @ 200 ppm under November II fortnight sowing and irrigation at 1.0 ETc. Further, November II fortnight sowing with deficit irrigation at 1.0 ETc and foliar application of thiourea @ 400 ppm or salicylic acid @ 200 ppm emerged as an effective strategy for enhancing dicoccum wheat productivity and resulted in water saving.