巴州地区棉花对化学打顶剂的响应机制

Response Mechanism of Cotton Varieties in Bayingol Area to Chemical Topping Agents

为明确在新疆巴州地区不同主栽棉花品种对化学打顶剂的响应机制,以4种当地主栽棉花品种为研究对象,分析化学打顶剂增效DPC处理对不同棉花品种的株高、叶面积指数(LAI)、地上生物量累积以及产量、品质的影响。研究结果表明,打顶30 d后,化学打顶处理的棉花的株高显著高于人工打顶4.09%~7.54%(P<0.05),‘巴43541’提高最少;2种打顶方式下不同品种棉花的LAI为2.96~4.03,相比于打顶前,‘巴43541’的LAI在化学打顶方式下增加最多;2种打顶方式处理后,不同棉花品种叶片、茎秆、蕾铃以及总干物质量的变化不同,但2种方式下干物质量的变化差异不显著(P>0.05);与人工打顶相比,化学打顶对不同棉花品种的纤维长度、整齐度、比强度、马克隆值以及伸长率影响不大;相比于人工打顶,在化学打顶方式下不同棉花品种的籽棉产量有所增加,增幅为0.35%~2.49%,其中‘巴43541’增产最高,为163.15 kg/hm^(2),其次依次为‘新陆中71号’、‘新陆中78号’和‘新陆中81号’。巴州地区主栽棉花品种‘巴43541’对化学打顶剂的响应最为明显,化学封顶效果最佳,且具有增产潜力。

In order to clarify the sensitive response of different main cotton varieties to chemical topping agents in Bayingol Mongolian Autonomous Prefecture of Xinjiang,four local main cotton varieties were selected as the research objects to study and analyze the effects of DPC(25%slow-release emulsion in water)treatment with chemical topping agents on plant height,LAI,aboveground biomass accumulation,yield and quality of different cotton varieties.The results showed that 30 days after topping,the plant height of different cotton varieties was significantly higher than that of artificial topping by 4.09%-7.54%(P<0.05),among which‘Ba 43541’increased the least.LAI of different cotton varieties under two topping methods ranged from 2.96 to 4.03.Compared with before topping,LAI of cotton variety‘Ba 43541’increased the most under chemical topping method.The changes of leaves,stems,buds and total dry matter mass of different cotton varieties under two topping methods were different,but the changes of dry matter mass under two topping methods were not significant(P>0.05).Compared with manual topping,chemical topping had little effect on fiber length,uniformity,specific strength,micronaire value and elongation of different cotton varieties,and the difference was significant.Compared with manual topping,the yield of seed cotton of different cotton varieties increased by 0.35%-2.49%under chemical topping,among which the yield of cotton variety‘Ba 43541’was the highest,with 163.15 kg/hm^(2),followed by‘Xinluzhong 71’,‘Xinluzhong 78’and‘Xinluzhong 81’.‘Ba 43541’,the main cotton variety in Bayingol,is the most sensitive to chemical topping agent,and has the best effect of chemical capping,and has the potential to increase production.