Standardization of plant geometry of different Bt cotton hybrids for high density planting under drip irrigation

A field trial was conducted at Cotton Research Farm, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola during the kharif season of 2024-25 to evaluate the response of different Bt cotton hybrids under varying plant geometry under drip irrigation. Three Bt hybrids viz. AKHH 2022-1 Bt, RCH-971 BG-2 and SWCH 4823 BG-2 with three plant geometry viz. 90 cm x 15 cm, 90 cm x 30 cm and 90 cm x 45 cm were laid out in factorial randomized block design with three replications and nine treatment combinations. The field was equipped with an inline drip irrigation system with 16 mm laterals placed at 90 cm apart and drippers spaced 40 cm apart. The results showed that Bt cotton hybrid AKHH 2022-1 Bt recorded significantly higher crop growth, dry matter accumulation, leaf area, chlorophyll content, number of sympodial branches per plant and number of picked bolls per plant compared to other Bt cotton hybrids. AKHH 2022-1 Bt also topped in seed cotton yield (3134 kg ha^-1) and lint yield (1165 kg ha^-1) significantly over other Bt cotton hybrids. In context to plant geometry Bt hybrids planted at 90 cm x 45 cm provided better crop growth, dry matter accumulation, leaf area, chlorophyll content, number of sympodial branches per plant, number of picked bolls per plant and seed cotton yield per plant compared to plant spacing of 90 cm x 15 cm and 90 cm x 30 cm. However, the denser plant spacing of 90 cm x 15 cm gave significantly highest seed cotton yield (3435 kg ha^-1) and lint yield (1260 kg ha^-1), which was significantly better than rest of wider spacings. Besides this, AKHH 2022-1 Bt and denser spacing 90 cm x 15 cm registered significantly higher GMR, NMR and B:C ratio. Whereas, in interaction effect AKHH 2022-1 Bt sown at 90 cm x 15 cm closer spacing recorded higher NMR of Rs 145573 and B:C ratio 2.72.