Abstract

A Field experiment was carried out at the experimental farm of El-kod Agricultural Research Station, Abyan Governorate, during 2010 and 2011seasons. The study aimed at determining the influence of four levels of nitrogen fertilizer (No, N30, N60 and N90 kg / ha) in the form of urea 46% N on growth of long-staple cotton cultivar (Muallem 2000). The experiment included 4 treatment. The design of each experiment was RCBD with four replications was used. The area of each plot was 12 m2. The values of the first flower and the first boll opening were not affected significantly by nitrogen fertilization rates in both seasons; While the increase in the rates of nitrogen fertilization led to the significant increase in the following values: plant height, the height of the first sympodia, the number of monopodia and sympodia/ plant and leaf area in both seasons, has made treatment N90 highest values, and the least up to the values were planted when the control treatment in both seasons Nitrogen fertilizer reflected significantly linear regression correlation to increase plant height, the number of sympodia/plant and leaf area in both seasons, in addition to positive significant correlation with plant height, sympodia/plant and leaf area.