膜下滴灌棉花随水根施多效唑的效果分析与化控技术的探讨

Effect of applying PP_(333) to cotton roots with drip irrigation under film-mulching and new chemical control technology

膜下滴灌棉花随水根施多效唑具有明显的增产效果,比对照增产10%～20%,群体结构合理,株高适宜,平均比对照低5～7.5cm,降低10%～15%。叶面积减小,叶倾角增大,散射光透过率增强,通风透气性好。第一果枝高度降低,单株结铃数增多,铃质量增加,营养生长和生殖生长相协调。植株中后期叶绿素含量高值持续期长,膜相对透性小,抗早衰。适宜纯多效唑浓度范围为36～72g/hm2(合有效成分15%的多效唑240～480g/hm2),最适为54g/hm2左右。理论上第一次化控偏重于浓度上限,第二次偏重于中下限,生产上要根据棉株长势和土壤肥力具体决定。对于土壤肥力高,棉株长势过旺的棉田应相应加大浓度,但最大不能超过90g/hm2。此外,该文对在大田条件下滴灌棉花的化控技术进行了探讨,提出了"上喷兼下施"(空间上)和"前促中控后促"(时间上)的新方法。

There is an obviously improved yield in cotton fields after applying PP_(333 ) to its roots, compared to CK, which improved 15 percent and more. As to its physiological aspects, the canopy structures gets rational, the hight of cotton plant becomes appropriate, and it is shortened by 5~7.5 cm, than CK. The high data of chlorophy11 keeps long and the injury of plasma lemma is slight. All of these ensured that cotton have not been dying too early. According to experiments, appropriate concentration is from 36 g to 72 g (Unit: pure PP_(333) mass/hm^2, the follows are same), and the best is about 54 g/hm^2. But for the over-growing cotton field, the concentration ought to have a promotion. However, the biggest concentration should never above 90 g. The chemical control technology for dripping irrigated cotton was discussed, and some new measures, which are spring growth accelerators on leaves and dripping growth retardant on roots with water, was brought out, at the same time (from aspect of spatial); Technology of accelerating cotton growth during seedling period, inhibiting growth during blooming-boll, and the second times accelerating during the latter time of cottons growth stage(from aspect of time) was put forward.