| Colony quality of cotton under high planting density of 18×104 plants/hm2,22.5×104 plants/hm2 and 27×104 plants/hm2 was studied with the same climate, soil texture, fertility and water conditions in Yuli county in Xinjiang. The results showed that the lint yield of cotton decreased with the density increased. The main indexes of colony quality such as bolls quantity of unit area, weight of single boll, boll setting rate, dry matter accumulation and leaf area index were optimal under the density of 18×104 plants/hm2. The results proved that the density of cotton could not be exceeded 18×104 plants/hm2 in the high-fertility fields at northeastern border of Tarim Basin under current cultivating conditions. |