M.A. Thesis:

survey the efficacy of time and amountof consuming naphthalene acetic acid onperformance and performance components of cotton

In order to determination of the nest time and concentration of Nafatline Acetic Acid (NAA) on yield and yield component of Cotton in saline condition, AN experiment was conducted as factorial arrangement based on randomized complete block design in Sabzevar in 2015-2016. Factors were: NAA concentration (0, 10, 20 and 30 ppm) and time of foliar application (at early flowering, at peak boll formation and at early flowering+peak boll formation ). Plant height, monopodial and sympodial branch number, number of open and unopen bolls, boll weight, seed cotton per boll, lint percent, seed cotton yield, lint yield and biological yield were studied. Varamin cultivar used in this study. Increasing of NAA concentration to 30 ppm increased plant height (13.45%), sympodial branch number (17.42%), boll number (62.67%), boll weight (75.18%), seed cotton per boll (58.39%), seed cotton yield (15.46%), lint yield (22.63%) and biological yield (6.07%) compared than control. Foliar application at early flowering+peak boll formation had the highest sympodial branch number, the number of bolls per plant, boll weight, seed cotton per boll, seed cotton yield and biological yield, While the highest number of unopened bolls was in spraying NAA at flowering stage. Overall results showed that spraying with NAA at a concentration of 30 ppm at early flowering+peak boll formation stage of cotton can be obtained best seed cotton yield and lint yield.

Keywords: Cotton, Foliar application, Time of spraying, Naphthalene Acetic Acid, Salinity