Increasing complexity in crop nutrient requirement in intensive crop production system needs alternative multi-nutrient sources. The field investigation entitled, “Effect of Polyhalite multinutrient fertilizer and drip irrigation at different ETc levels on growth, quality and water use efficiency of Bt. cotton in Inceptisol” conducted during the years 2020 and 2021 at AICRP on Irrigation Water Management Farm, Mahatma Phule Krishi Vidyapeeth, Rahuri, Dist. Ahmednagar (Maharashtra).The present investigation was laid out in Split plot design with three replications. Total fifty four treatment combinations comprising three irrigation regimes as main plot treatment viz., I1-0.8 ETc, I2-1.0 ETc and I3-1.2 ETc and six fertilizer doses as sub plot treatments. viz., T1- Absolute control, T2 - 100% GRDF (125:65:65 N: P2O5: K2O kg ha-1), Mg, S as per recommendation, T3- 100 % N: P2O5 + 100% K2O through polyhalite, T4-100 % N: P2O5: 25 % K2O through muriate of potash + 75% K2O through polyhalite, T5- 100 % N: P2O5: 50 % K2O through muriate of potash + 50 % K2O through polyhalite, T6- 100 % N: P2O5: 75 % K2O through muriate of potash + 25% K2O through polyhalite. The data revealed that scheduling of irrigation at I2-1.0 ETc irrigation regime registered significantly higher growth attributing characters of Bt. cotton viz., plant height (147.36 cm), number of sympodial branches plant-1(21.67), leaf area plant-1 (282.16 dm2), Number of bolls plant-1 (34.53) is at par with 0.8 ETc irrigation regime than rest of irrigation methods at harvest during pooled mean of two years. While in case of fertilizer treatment F4-100% N: P2O5: 25% K2O through MOP + 75% K2O through Polyhalite showed highest plant height (146.30 cm), number of monopodial branches plant-1 (1.41) number of sympodial branches plant-1 (20.33), leaf area plant-1 (280.16), Number of bolls plant-1 (28.94). Other quality traits, viz., ginning percentage, upper half mean length, uniformity index and micronaire ratio were not influenced by the both irrigation regimes and fertilizer treatments. Study concluded that polyhalite shows potential as a commercial fertilizer to supply K, Ca, Mg, and S nutrients. However, the availability of polyhalite will remain a challage and its location and crop specific response needs to be studied for its advocation as a complete K nutrient source for soil.

Polyhalite, cotton, Drip irrigation, quality

Irrigation regimes with scheduling of deficit irrigation at 0.8 ETc is significant among other irrigation levels with 20 percentage of saving cost coupled with application of 100% N: P2O5: 25% K2O through MOP + 75% K2O through polyhalite recorded significantly highest growth contributing characters. The quality parameters viz. ginning percentage, 2.5 % span length, uniformity ratio, micronaire value, elongation and bundle strength were not influenced significantly due to different irrigation regimes and fertilizer treatments during both the years. overall, this research contributes to sustainable agriculture practices, a balanced and prolonged supply of a nutrients with polyhalite to crop in sustained manner can be maintained.

Utkarsha Viju Amolic, Ritu S. Thakare, V. S. Patil, B.D. Bhakare and B.M. Kamble (2023). Effect of Polyhalite Multinutrient fertilizer and Drip Irrigation under different ETc Levels on Growth, Quality of Bt. cotton in Inceptisol. Biological Forum – An International Journal, 15(11): 410-415.