Two field experiments were conducted at Sids Agricultural Re­search Station during 1996 and 1997 seasons, to study the response of cotton plants to some cultural practices, i.e. the time of first irrigation, fresh foliar application of 1.55% P2O5 and soil application of N fertilizers and topping after 105 days after sowing date, to control the excessive vegetative growth and its effects on some growth characters, yield and yield components and some fiber properties of Giza 80 cotton cultivar plants. The obtained results showed that applying the first irrigation af­ter 21 days from sowing date increased the number of open bolls/plant, boll weight, seed cotton yield/fed. and earliness percentage. While, plant height, length of inter-node and number of fruiting branches/plant were decreased. Seed index, lint percentage and fiber properties were not af­fected. Results also indicated that excessive vegetative growth of plants that occurs in case of applying high amount of N fertilizer (75 kg N/fed) can be controlled by some cultural practices such as applying foliar appli­cation of 1.55% P205 or topping the plants after 105 days from sowing date and these traits consequently led to increased stimulation of yield components characters and caused high seed cotton yield. All characters were not affected by interaction between time of first irrigation and all treatments in both seasons.