【摘要】 为探讨棉花打顶剂在长江流域对麦后直播棉产量及生长发育的影响,以早熟棉品种‘中棉所50’为材料,于2016-2017年在江苏省宿迁市开展打顶剂（DPC+）的比较试验。结果表明:喷施打顶剂棉花株高和果枝数显著高于人工打顶、低于不打顶,而上部果枝长度显著低于人工打顶和不打顶,株型更加紧凑、通风透光好。新生节间长度和新生果枝长度在不同剂量打顶剂处理下差异显著,而且随着打顶剂剂量增加长度逐渐变小,同时在人工打顶时间喷施打顶剂处理显著长于推迟5 d喷施打顶剂处理。单株成铃数基本表现为打顶剂处理高于人工打顶及不打顶处理,且人工打顶时间喷施打顶剂处理高于推迟5 d喷施打顶剂处理,单铃质量、衣分以打顶处理基本高于不打顶处理。连续2 a在人工打顶时间喷施打顶剂（DPC+） 1 125mL·hm^-2条件下,实际籽棉产量、皮棉产量平均达3 994.20 kg·hm^-2和1 464.10 kg·hm^-2,比人工打顶条件下分别稳定增产0.9%和1.0%,且在此处理下,群体叶面积指数较为适宜（约4.0）、棉株功能叶叶绿素含量较高。更多还原

【Abstract】 In order to study the effect of cotton topping agent on the yield and growth of direct seeded cotton after wheat in the Yangtze River Valley, the comparative experiment of topping agent DPC+ was conducted in Suqian city, Jiangsu province, with the early maturing cotton variety ‘Zhongmiansuo 50’ as the material, from 2016 to 2017.The results indicated that the plant height and fruit branch number of cotton spraied topping agent were significantly higher than that of manual topping and lower than that of non-topping, while the length of upper fruit branch was significantly lower than that of manual topping and non-topping, which resulted in more light transmittance in middle and lower layer of cotton canopy.The length of new internode and fruit branch were significantly different under different concentration of topping agent, and the length became smaller with the increasing of concentration of topping agent, under the condition of spraying topping agent at manual topping time, both of them are longger.The number of bolls per plant in the treatment of topping agent was higher than that of manual detopping and non-topping, and spraying topping agent at manual topping time were higher than that of spraying topping agent 5 days later.The treatment without topping were the lowest in boll weight and lint percentage.Under the condition of manual topping time spraying agent DPC+ 1 125 mL·hm^-2 in 2016-2017 cotton seasons, the actual seed cotton yield and lint yield respectively reached 3 994.20 kg·hm^-2 and 1 464.10 kg·hm^-2,which increased steadily by 0.9% and 1.0%, compared with manual topping.The leaf area index of population was about 4.0 and the chlorophyll content was higher.更多还原