Cotton is one of the most important and strategically crops all over the world especially in Iran which is grown to use both fiber and oil. In improving management of cotton cultivation, irrigation, nutrition and their interaction are very important. So, this study was conducted to evaluate the effect of soil moisture, foliar application of micronutrients and their interaction on yield and quality characteristics of cotton fiber at the Research Farm of Isfahan Islamic Azad University (Khorasgan Branch) in a split plot layout with three replications in 2009. Irrigation treatments based on 80 and 160 mm cumulative evaporation from evaporation pan class A were regarded as the main factor and without, two times and three times foliar application of micronutrients were applied as sub-factor. The traits including unginned cotton (lint+cotton seed) yield, lint yield and some of lint qualitative traits such as mean length, uniformity index, elongation, strength, fineness and short fiber index were calculated and analysis of variance was performed for each one of the traits. The results showed that the effect of irrigation on above all traits was significant at the 1% probability level. Drought stress (irrigation based on 160 mm cumulative evaporation) caused 7% increase in unginned cotton yield. In fact, much moisture stimulated vegetative growth and delayed reproductive development, as a result unginned cotton has decreased. Also, a similar result was obtained about the characteristics above. Three times foliar application of micronutrients than the control increased both unginned cotton and lint yield about 8% and improved all qualitative fiber traits. Maximum and minimum lint yield equal to 87.96 and 73.67 g/m(2) was obtained in association With irrigation based on 80 mm cumulative evaporation with three times foliar application of micronutrients and irrigation based on 160 mm cumulative evaporation without foliar application of micronutrients, respectively.
