ATTEMPTS TO CONTROL EXCESSIVE VEGETATIVE GROWTH OF COTTON

Two field experiments were carried out at Sakha Agricultural Re­search Station during 1997 and 1998 seasons, using the Egyptian cot­ton cultivar Giza 87 (G. barbadense L.) to study the effect of some cul­tural treatments in order to check excessive vegetative growth i.e. topping at 120 days age, spraying 8 kg/fed. super phosphate (15% P₂ 0₅) on mid-July and 15 days later, spraying Pix (mepivat chloride) 500 ml/fed. (50 gm a.i/L) twice in the beginning of squaring and 15 days lat­er and single spray of Pix at the beginning of squaring +topping at 120 days age, besides untreated control. The results indicated that the dif­ferent treatments significantly affected all the studied characters com­pared to the control except number of fruiting sites whereas they re­duced final plant height, main stem internodal length. monopodia. sympodia, aborted sites and unopen bolls/plant. In general the studied treatments increased boll retention, earliness percentage, number of open bolts, boll weight, lint percentage, seed index and seed cotton yield (Kintar/fed.). The main prominent effect was detected with single spray of Pix + toping followed by two sprayings of Pix specially for seed cotton yield and its components.