Effect of growth regulators on productivity of late sown wheat (Triticum aestivum L.) in Chhattisgarh

Abstract:

An investigation entitled “Effect of growth regulators on productivity of late sown wheat (Triticum aestivum L.) in Chhattisgarh” was carried out during rabi season 2025-26 at the Instructional Cum Research Farm, Barrister Thakur Chhedilal College of Agriculture and Research Station, Bilaspur (C.G.). The treatments consisted of ten different growth regulator treatments viz., T₁ - Foliar application of GA₃ @ 10 ppm at tillering, T₂ - Foliar application of GA₃ @ 20 ppm at tillering, T₃ - Foliar application of GA₃ @ 40 ppm at tillering, T₄ - Foliar application of GA₃ @ 80 ppm at tillering, T₅ - Foliar application of GA₃ @ 160 ppm at tillering, T₆ - Foliar application of ABA @ 50 ppm at anthesis, T₇ - Foliar application of ABA @ 100 ppm at anthesis, T₈ - Foliar application of ABA @ 150 ppm at anthesis, T₉ - Foliar application of ABA @ 200 ppm at anthesis and T₁₀ - Control. Observations on growth parameters viz., plant population, plant height, number of tillers, plant dry matter accumulation, crop growth rate and relative growth rate at different stages of crop growth, along with phenological parameters including crown root initiation, flag leaf stage, booting, heading and anthesis, were recorded. Growing degree days and photothermal units required for attaining different phenological stages were also calculated. Yield and yield-attributing parameters including ear length, number of ears m^-2, number of grains ear⁻¹, test weight, grain yield, straw yield and harvest index, along with economic parameters such as cost of cultivation, gross return, net return and benefit cost ratio, were recorded and subjected to statistical analysis. The results indicated that growth and phenological parameters of late-sown wheat were significantly influenced by the application of growth regulators. The highest plant height, number of tillers and plant dry matter accumulation at different stages of crop growth were generally recorded under T₅ - foliar application of GA₃ @ 160 ppm at tillering, followed by T₄ - GA₃ @ 80 ppm. Treatment T₅ also promoted comparatively earlier attainment of flag leaf, booting, heading and anthesis stages and required lower growing degree days and photothermal units for advancement through successive phenological stages. The control treatment T₁₀ generally recorded comparatively lower growth and delayed attainment of reproductive stages. Yield and yield-attributing parameters were also considerably influenced by the application of growth regulators. Treatment T₅ - foliar application of GA₃ @ 160 ppm at tillering recorded the maximum ear length (9.74 cm), number of ears (314.07 m⁻²), number of grains ear⁻¹ (35.34), test weight (44.30 g), grain yield (38.78 q ha⁻¹), straw yield (42.49 q ha⁻¹) and harvest index (47.66%). The highest gross return (₹ 98,301 ha⁻¹) was also obtained under T₅. However, the highest net return (₹ 63,051 ha⁻¹) and B:C ratio (1.90) were recorded under T₃ - foliar application of GA₃ @ 40 ppm at tillering. The lowest growth, yield and economic performance was generally recorded under T₁₀ - Control, which recorded the lowest gross return (₹ 69,251 ha⁻¹), net return (₹ 38,193 ha⁻¹) and B:C ratio (1.23).