不同密、肥水平下苏棉９号生育主要特点有：株高、果枝台数、主茎果枝节间距等随密度和施肥量的增加而增加；果枝节位数随密度下降（或施肥量增加）而增加；单株结铃数（率）随密度增加而下降；棉铃的分布以中、下部和内围铃为主；伏秋桃比一般在６∶４～７∶３之间，稀植（或高肥）条件下霜后花和僵瓣花的比例增加以及增密的效益比增肥的效益要高等特点。合理密植、控制氮肥用量，可协调营养生长和生殖的关系，控制主茎节间距和果枝长度，减少外围果节的结铃数，改善田间通风透光条件，提高结铃率，促进早熟，提高品质，提高种植苏棉９号的效益。 Under the different density and fertilizer level, the main characteristics of Sumam 9 were as follows: the height of plant, the number of fruiting branches and the branch spacing of main branch increased with the increase of density and fertilizer amount; the number of branch of fruiting branches decreased with the density (or the amount of fertilizer increased) While boll number (rate) per plant decreased with the increase of density. The distribution of cotton bolls was mainly in the middle and lower part and the inner ring bell; the ratio of autumn and fall peach was generally between 6: 4 and 7: 3, Or high fat) under the conditions of post-frost and flower petals increase the proportion of flowers and the benefits of increased density than the benefits of higher fat. Reasonable and close planting, controlling the amount of nitrogen fertilizer can coordinate the relationship between vegetative and reproductive, control the pitch and fruit branch length, reduce the number of bolls, improve field ventilation and light conditions, improve the boll rate, promote premature, improve Quality, improve the benefits of planting Su cotton on the 9th.