Effect of irrigation, foliar application of methanol and plant density on morphophysiology traits, yield and yield components of cotton (Gossypium hirsutum L.)

In order to evaluate the effect of irrigation, foliar application of methanol and plant density on morphophysiological traits, yield and yield components of cotton, a split-split-plot experiment based on randomized complete block design with three replications was conducted in Birjand, Iran in 2014. The main plots were irrigation interval (irrigation after 120 and 240 mm cumulative evaporation), the sub-plots were methanol spray (0, 10and 20 volume percent) and the sub-sub-plots were plant density (10 and 20 plants. m-2). The results showed that irrigation interval significantly affected plant height, branch number of main stem, stem diameter, stomatal conductivity, chlorophyle index, relative water content, boll number per m2, yields of seed, lint, seed cotton and biological. As decreased irrigation interval from 240 to 120 mm cumulative evaporation, these traits significantly increased by 16.3, 48.8, 25.3, 105.4, 11.6, 23.6, 60.9, 60.8, 76.6, 68.9 and 55.6%, respectively. Also, foliar application of methanol significantly increased boll number per m2, yields of seed, lint, seed cotton and biological.  Moreover, plant height, boll number per m2, yields of seed, lint, seed cotton and biological increased by 14.4, 23.5, 15.4, 26.7, 21.2 and 17.6 %, respectively with the increase in olant density from 10 to 20 plants. m-2. The results showed that irrigation after 120 mm cumulative evaporation, application of 10volume percentof methanol and density of 20 plants. m-2 are suitablefor thecultivation of cotton in Birjand, Iran.