Promotion of Growth and Yield Parameters of Cotton by Phytohormones in Conjunction with Organic and Inorganic Nutrients

Cotton is an important fiber and cash crop in India, contributing significantly to the country's industrial and agricultural economies. Cotton in India is a direct source of income for 6 million farmers, while the cotton trade and processing employs approximately 40-50 million people.

Recently, there has been a greater interest in the commercial use of plant growth regulators in cotton production, particularly in light of the growing threat posed by climate change. According to recent research, organic nutrients are preferred over inorganic ones when applied in small amounts.

During August–Jan (2021–2022), a field experiment was carried out in the farmer's field at Jayapuram Village, Natrampalli Taluk in Thirupathur District to examine the impact of applying NPK fertilizers, compost enriched with zinc, and foliar spraying ZnO2 and NAA on improving cotton yield and quality in sandy loam soil.

Using Urea, SSP, and MOP, fertilizers (N: P2O5: K2O) were given at the proper dosage (60:30:30 kg ha-1). One week before planting, 1.0 t ha-1 of Zn-EC was used as a baseline. ZnO2 was administered twice during the crop's vegetative and blooming stages at a rate of 0.1% as part of the therapy. During blooming and boll formation, NAA at 40 ppm was sprayed twice as part of the treatments.

The results of the field experiment proved that soil application of 75% RDF + Zn – EC @ 1.0 t ha-1 and foliar spray of ZnO2 @ 0.1% + NAA @ 40 ppm (T9) will be an effective management practice for achieving better yield, quality in cotton with due care on soil fertility. The conclusion made from this study is the farmers might enhance cotton production as well as quality by applying 75% required NPK, zinc-enriched compost at 1.0 t ha-1, and foliar sprays of ZnO2 at 0.1% and NAA at 40 ppm in sandy loam soil. The treatment improved sandy loam soil health, including physical, chemical, biological, and nutrient availability. The current study clearly shows how the application of different organic and inorganic fertilizers improves both the quality and yield metrics of cotton, which is in high demand on the global market.