Agronomic response of different cotton cultivars and hybrids to changes in plant density

To investigate the agronomic response of cotton cultivars and hybrids at different densities this study was conducted in 2017 and 2018 on the farm of the National Cotton Research Institute, Varamin, Iran. 10 cultivars and hybrids including Varamin, Bakhtegan, Sajedi, Sahel, T2, T14 and hybrids (Sahel × Sajedi), (Bakhtegan ×T2), (Varamin ×T14), and (Sajedi ×T14) under 5.5, 6.4 and 12.8 plants per square meter were evaluated. The field experiment was performed as a split-plot in a randomized complete block design with 4 replications. During the growing season and after the physiological maturity stage, plant yield, boll weight, number of bolls per plant, plant fiber weight, seed weight per plant, and plant height were carefully measured. During the growing season and after the physiological maturity stage, plant yield, boll weight, number of bolls per plant, plant fiber weight, seed weight per plant, and plant height were carefully measured. The results of comparing the mean interaction of cultivar and plant density on plant yield showed that ور hybrid cultivar Varamin× T14 at a density of 5.5 plants per square meter in the crop years 2017 and 2018, respectively, had the highest plant yield, a number of bolls per plant, fiber weight, grain weight per plant To other cultivars and hybrids studied. Also, the results of this study showed that the density of 5.5 plants per square meter is very suitable and recommended for cotton and especially for the new hybrid of Varmin×T14, which had better quantitative and qualitative characteristics than other cultivars.