田间条件下遮光对棉花棉铃发育及纤维品质的影响

Effects of Shading on Boll Development and Fiber Quality in Field Grown Cotton

研究了4个棉花品种花铃期遮光对棉铃发育及纤维品质的影响。结果表明,遮光导致棉花单株结铃数减少,棉铃最终生长量、最大干物质积累速率、干物重相对增长速率及单铃棉子数、铃壳重、粒重、纤维重降低。遮光对棉铃各组分的影响依次是纤维>子粒>铃壳。遮光后纤维长度增加,比强度和麦克隆值显著下降,但对伸长率及整齐度影响不显著。在自然光照条件下密植使纤维比强度降低显著,纤维长度有所增加,对其它品质指标影响不显著。应从选育品种、塑造合理株型、适当控制种植密度等措施入手,减轻弱光对棉铃发育及纤维品质的影响。

Four cultivars were grown in the field under three light treatment(shading 25% and 50% with density of 60×10~3plants·hm^(-2), the controls of no shading were CK1 with density of 60×10~3plants·hm^(-2) and CK2(high density) with density of 262×10~3plants·hm^(-2))in Shihezi in 2002 and 2003. The results showed that both shading and high density could cause the decreasing of boll number and the increasing of immature and rotten bolls per plant. The values of final boll weight(K) of 25%SH reduced 17.9% and 12.2%, and 50%SH reduced 38.7%and (34.5%,) compared with CK1 and CK2. The values of maximum accumulation rate of boll dry matter(G(max)) of 25%SH decreased 34.7% and 33.1%, and 50%SH reduced 50.5% and (49.3%), compared with CK1 and CK2. The values of relative growth rate(B) decreased with shading and density increasing. The weight of cotton hull, seed and fiber reduced significantly but no significant decreasing of seeds per boll with shading and density increasing. The seeds of 25%SH reduced 1.6 and 1.3 grain per boll, and 50%SH decreased 6.3 and 6.0 grain per boll, compared with CK1 and CK2. The values of seed weight of 25%SH decreased 7.5% and 5.7%, and 50%SH reduced 30.1% and 28.7%, compared with CK1 and CK2. The values of hull weight of 25%SH decreased 4.5% and 2.6%, and 50%SH reduced 17.1% and 15.4%, compared with CK1 and CK2. The values of fiber weight of 25%SH decreased 12.4% and 7.9%, and 50%SH reduced 42.6% and 39.5%, compared with CK1 and CK2. The rank of contribution of shading to the boll components were fiber weight, seed weight and hull weight, successively. It was found that the fiber length increased, and strength and micronaire value reduced with shading increasing, and with no significant impact of shading on fiber uniformity and elongation. High density(CK2) increased fiber length and decreased fiber strength.