Performance of American Cotton (Gossypium hirsutum L.) Genotypes to Nitrogen Levels Under High Density Planting System in Scarce Rainfall Zone of Andhra Pradesh

A field experiment was conducted at Regional Agriculture Research Station, Nandyal, Andhra Pradesh during kharif 2010–11 and 2011–12 on vertisols to find out the performance of American cotton genotypes to different nitrogen requirement under High Density Planting System (HDPS). The experiment was laid out in split plot design with three American cotton genotypes viz., Narasimha, Sivanandi and NDLH 1938 as main plots and four nitrogen levels viz., 75% Recommended Dose of Fertilizer Nitrogen (RDFN) (30 kg ha⁻¹), RDFN (40 kg ha⁻¹), 125% RDFN (50 kg ha⁻¹) and 150% RDFN (60 kg ha⁻¹) as sub plots and replicated thrice. All the genotypes were sown at spacing of 45 x 15 cm (14.9 plants m⁻²) as against 60 x 30 cm spacing (5.5 plants m⁻²) in traditional planting. The genotype NDLH-1938 recorded higher seed cotton yield (2433 kg ha⁻¹), higher net returns and BC ratio (Rs 82, 375/-and 3.08, respectively). Significantly higher seed cotton yield (2267 kg ha⁻¹), higher net returns and BC ratio (Rs 74, 120/-and 2.73, respectively) was recorded with application of 125% RDFN (50 kg ha⁻¹).