Abstract: In order to explore the effects of different prohexadione calcium amounts on characteristics and yield of cotton, field test was carried out, and variety of ‘Xinluzao 42’ cotton was used as experiment material. Four treatments of different prohexadione calcium amounts, including 10 g/hm2 (T1), 20 g/hm2 (T2), 30 g/hm2 (T3), 40 g/hm2 (T4) were set up, as well the commonly used chemical capping 750 g/hm2 (C), and the control sprayed with water (CK). The agronomic traits and economic traits of cotton under different treatments were detected and analyzed. The results showed that moderate dose of prohexadione calcium application had a positive regulatory affection on the improvement of cotton agronomic traits, biomass accumulation and distribution, as well as the yield and quality. The yield of seed cotton in treatment T3 and C were higher than other treatments, which increased by 11.83% and 36.32% respectively, compared with CK; their fiber length, uniformity, specific strength and elongation were also better than those of other treatments in general. In summary, spraying 30 g/hm2 of prohexadione calcium could effectively reduce plant height, increase plant biomass, single boll weight and improve fiber quality, but its affection was not better than chemical topping.

Key words: prohexadione calcium, cotton, agronomic traits, biomass, yield, chemical regulation

摘要： 为探索调环酸钙用量对棉花植株性状及产量形成的调控效应，在田间试验条件下，以棉花品种‘新陆早42号’为试验材料，设置不同处理，包括10 g/hm2调环酸钙（T1）、20 g/hm2调环酸钙（T2）、30 g/hm2调环酸钙（T3）、40 g/hm2调环酸钙（T4）、750 g/hm2化学封顶剂（C）和对照（CK）共6个处理，比较不同浓度调环酸钙喷施下棉花的农艺性状和经济性状，解析株高、生物量积累、单铃重、籽棉产量和纤维品质的动态变化规律。结果表明，适量的调环酸钙处理在改善棉花农艺性状、生物量积累与分配及提升产量、改善品质上均有一定的调控作用。其中，处理T3和C的籽棉产量最高，分别较CK增加11.83%和36.32%，棉纤维的长度、整齐度、比强度、伸长率等整体效果也最优。综上，喷施30 g/hm2的调环酸钙能够有效降低株高、提高植株生物量、单铃重及改善纤维品质，其效果仅次于化学打顶处理。

关键词: 调环酸钙, 棉花, 农艺性状, 生物量, 产量, 化学调控