棉花化学封顶对植株上部枝叶形态变化的影响

Effect of Chemical Topping on Morphologic Changes of Leaves and Branches in Upper Part of Cotton

为探讨化学封顶剂的主要作用部位和效果,提高化学封顶效率,挖掘高产潜力。以人工打顶为对照,设置不同化学封顶剂量,通过用药前对上部主茎、果枝、叶片进行标记,研究化学封顶剂对棉花上部枝叶形态的影响。结果表明,化学封顶处理棉花最终株高高于人工打顶处理5cm以上,但封顶剂剂量越大对株高抑制越明显。化学封顶剂抑制株高作用主要体现在抑制上部主茎节间伸长,但对下部主茎节间伸长可能有促进作用。化学封顶标记的上部主茎直径相比人工打顶处理变小,果枝长度缩短,叶宽变窄,SPAD值有上升趋势,更利于通风透光和光合作用。棉花上部蕾铃数增加且增长速度加快,但最后成铃率不高。分析认为,化学封顶剂影响上部枝叶形态,使株型紧凑,蕾铃增多,但对最后成铃影响不大。

To discuss the main acting part and effect of chemical capping agent in cotton,so as to improve the efficiency of chemical caping and to tap potential of high yield.Conventional decapitation topping as CK.By marking on the upper part of the stem,leaves and branches before the test,we used different dose of chemical topping agent to study effect of chemical topping on morphologic changes of leaves and branches in upper part of cotton morphologic changes.The results showed that plant height of cotton treated by chemical agent topping was 5cm higher than that of one treated by artificial topping.but the more dose of chemical agent used,the more obvious the inhibition had.The chemical topping agent mainly functioned in inhibiting upper internode elongation,but it maybe could promote the lower internode elongation.The diameter of upper stem got smaller,branch length got shoter,leaf width got narrow,the SPADvalue was on the trend of increase,it was more conducive to ventilation and photosynthesis.The cotton boll numbers increased and the growth rate accelerated,but the rate of boll-setting was low at end period of growth.The analysis showed that chemical topping agent affected foliage morphology in the upper part of cotton,so the plants were compact,boll increased,but had little influence on cotton bolling.