Feasibility of desi cotton (Gossypium arboreum L.) to high density planting system and its fertilizer requirement in rainfed region of South Gujarat

An experiment was conducted during Kharif seasons of three years from 2019 to 2021 at Regional Cotton Research Station, Navsari Agricultural University, Bharuch to study the feasibility of an Arboretum cotton to high density planting system and to optimise its nitrogen requirement under rainfed cotton growing area of South Gujarat. Nine treatment combinations comprised of three levels of spacings viz two spacing of HDPS (60 x 15 cm and 60 x 30 cm) and one normal spacing (120 x 45 cm) with three nitrogen levels viz 120 kg N/ha, 150 kg N/ha as well as 180 kg N/ha were laid out in Factorial Randomised Block Design with three replications. In growth characters, significantly higher plant height was recorded in plant spacing 60x15 cm over both the remaining spacings. Significantly higher number of sympodial branches/plant and values of sympodial length were recorded in plant spacing 120x45 cm over remaining spacings. Plant spacing 60x15 cm recorded significantly less days to 50% flowering and boll bursting over both the spacings. Nitrogen level 180 kg N/ha recorded significantly higher plant height, number of sympodial branches/plant and sympodial length than 120 kg and 150 kg N/ha. Whereas significantly lower days to 50% flowering and boll bursting were recorded in nitrogen level 120 kg N/ha than 150 kg and 180 kg N/ha. Among yield attributing parameters, both the HDPS treatments (60x15 cm and 60x30 cm) were produced statistically higher number of bolls/square meter area over normal spacing (120x45cm). Nitrogen level 180 kg/ha recorded significantly higher number of bolls/square meter area than remaining nitrogen levels. Boll weight was not affected significantly by plant densities, nitrogen levels and their interaction (Spacing x Nitrogen). Individual effect of plant spacing and nitrogen levels were found significant on seed cotton yield/plant. Interaction effect of (Spacing x Nitrogen) was also found significant on seed cotton yield/plant. Plant spacing and nitrogen levels were non-significantly affected the seed cotton and lint yield (kg/ha).