Effects of deficit irrigation and plant density on yield and yield components of cotton in Varamin

To study the effect of deficit irrigation and plant density on yield and yield components of the Cotton cultivar Varamin, an experiment was conducted at research farm of Cotton Research Institute, Varamin in 2006, using split- split- plot on the basis of randomized complete, Block design with 16 treatments and three replication. Main plots consisted of plant density in four levels of 80×10, 80×20, 70×10, and 70×20 sub plot consisted of irrigation regimes in two levels of 8 days and 12 days periods on farm's Cotton Research Institute of Varamin (35°19' N, 51°39' E; elevation 1050 m above sea level). Treatments were consists of: Main plot: plant density in 4 levels including (factor A) and Sub plot: irrigation regime in 2 levels including 8 and 12 days period with equal amount of water, and Sub-sub plots were two irrigation methods of Conventional furrow irrigation and fix alternate furrow Irrigation. The results showed that alternate furrow irrigation method had significant effect () on plant height, boll weight and total yield of seed cotton, but its effect on number of sympodial branches and earliness was not significant.Plant density did not effect any of the measured traits. Fiber technological properties were not affected by any of the treatments. yield in alternate furrow method was significantly decreased (25.5 and 27.7 percent) compared to the all furrow irrigation method. The highest seed cotton yield (5319.8 kg.ha-1) was obtained in 70×20 plant density, with 12 days period and all furrow irrigation, and the lowest yield (2718.05 kg.ha-1) in 70×10 plant density with 12 days period and alternate furrow irrigation treatments.