滴灌棉花源库器官对化学打顶的响应特征

Response characteristics of source and sink organs of drip irrigation cotton to chemical topping

【目的】研究化学打顶对棉花光合特性及不同部位棉铃物质积累的影响和变化规律,为棉花优质高产提供基础。【方法】以新陆中70号和新陆中82号为材料,设置2种化学打顶药剂,人工打顶为对照。【结果】在喷施药剂10 d后,化学打顶处理的主茎功能叶净光合速率较人工打顶高,中上部叶片SPAD值化学打顶处理高于人工打顶处理,而新陆中82号下部叶片SPAD值表现为化学打顶低于人工打顶;新陆中70号积累量大于新陆中82号,但积累速率小于新陆中82号;化学打顶处理的全铃干物质积累表现为前2个花期促进后期棉铃的物质积累,2个品种分别是发育35和28 d后,而7月21日开花期促进是前期棉铃的物质积累,分别是发育28和21 d内;化学打顶处理的前2个开花期的增长特征值时间较人工打顶处理的有所推迟或增加,而7月21日开花期表现为化学打顶处理较人工打顶均有前移和增加,最大增长速率均表现为化学打顶处理大于人工打顶处理。【结论】化学打顶可以提高棉花主茎功能叶的光合作用,加速棉铃物质积累速率,有利于棉铃集中吐絮。

【Objective】To explore the effect of chemical topping on photosynthetic characteristics and the change rule of cotton boll material accumulation in different parts,provide a basis for high quality and high yield of cotton.【Methods】Taking Xinluzhong 70 and Xinluzhong 82 as materials,two chemical topping agents were set up in the experiment,and manual topping was used as control.【Results】The results showed that after 10 days of spraying,the net photosynthetic rate of the main stem functional leaves of the chemical topping treatment was higher than that of the artificial topping treatment,and the SPAD value of the middle and upper parts of the chemical topping treatment was higher than that of the artificial topping treatment,while the lower part of Xinluzhong 82 showed that the chemical topping was lower than the artificial topping.The accumulation of Xinluzhong 70 was greater than that of Xinluzhong 82,but the accumulation rate was less than that of Xinluzhong 82.The dry matter accumulation of the whole boll of the chemical topping treatment showed that the first two flowering periods promoted the dry matter accumulation of the late cotton boll,and the two varieties were developed after 35 and 28 d,respectively,while the flowering period on July 21 promoted the dry matter accumulation of the early cotton boll,which was developed within 28 and 21 d,respectively.The growth eigenvalue time of the first two flowering periods of the chemical topping treatment was delayed or increased compared with the manual topping treatment,while the flowering period on July 21 showed that the chemical topping treatment moved forward and increased compared with the manual topping treatment,and the maximum growth rate showed that the chemical topping treatment was greater than the manual topping treatment.【Conclusion】Chemical topping can improve the photosynthesis of the functional leaves of the main stem of cotton,accelerate the accumulation rate of cotton boll matter,facilitate the concentrated opening of cotton bolls.