超高茬麦田套稻田间杂草防除效果研究

目的]采用超高茬麦田套稻技术田间杂草危害严重,是其大面积推广应用的主要障碍之一,通过不同药剂的防效试验筛选最佳除草剂。方法]选用35.5%丁.恶乳油等除草剂在水稻套播后和小麦收割后,用毒土法先后2次处理麦田套播水稻田,调查防效。结果]除草效果以35.5%丁.恶乳油2 250 ml/hm2最佳,其后依次为30%丁.苄1 500 ml/hm2、50%杀草丹3 000 ml/hm2＋10%苄磺隆225 ml/hm2、50%苯噻草胺750 ml/hm2＋10%苄磺隆225 ml/hm2,而36%二氯.苄750 ml/hm2效果最差;用药时间越早,对禾本科杂草防效越好,供试药剂持效期均为45 d左右;中、后期可根据田间杂草发生情况辅以茎叶处理,效果更佳。结论]以稗草和阔叶杂草为主的田块,5种药剂均可使用;以千金子和阔叶杂草为主的田块,除36%二氯.苄750 ml/hm2外,其他4种药剂均可使用;以莎草科和阔叶杂草为主的田块,可用含有苄磺隆的复配除草剂,或单用10%苄磺隆225～300 ml/hm2进行防除。供试药剂均对水稻安全。

Research on the Efficiency of Weed-controlling in Rice Field with Ultra-high Wheat Stubble

Objective] The weed damage in rice inter-planted in wheat field with ultra-high stubble was one of main limiting factors in the application of technique.Thus,the best herbicide was selected through the experiment.Method] The five types of herbicide such as 35.5% Dingeruyou were sprayed in the field after rice-sowing and wheat-harvesting and the method of poisoned soil was adopted for twice.The controlling efficiency was investigated.Result] The order of the controlling efficiency of herbicide was 35.5% Dingeruyo 2 250 ml/hm2>30% dichloro bensulfuron-methyl of 1 500 ml/hm2>50% benthiocarb of 3 000 ml/hm2+10% bensulfuron-methyl 225 ml/hm2>50% mefenacet of 750 ml/hm2+10% bensulfuron-methyl 225 ml/hm2>36% dichloro bensulfuron-methyl of 750 ml/hm2.The earlier the treating technique of herbicide-spraying was,the better the weed-controlling was.The weed-controlling could last 45 days.In middle/late rice growth period,the herbicide could be applied depending on the situation of weed damage.Conclusion] In the field with the barnyard grass and broadleaf weed as main weed,the treatment of the 5 herbicides could produce good controlling efficiency.In the field with Chinesis sprangletop and broadleaf weed as main weed,the treatment of other 4 herbicides except 36% dichlore bensulfuron-methyl of 750 ml/hm2 could produce good controlling efficiency.In the field with nutsedge and broadleaf weed as dominate weed,the treatment of compound herbicide containing the component of bensulfuron-methyl or 10% bensulfuron-methyl of 225～300 ml/hm2 could produce good controlling efficiency.All of experimental herbicides were safe for rice rpoduction.