湖北移栽油菜田牛繁缕的发生规律及防除策略

牛繁缕Malachium aquaticum（L．）Fries是油菜田恶性杂草。采用固定样方和随机样方法研究了移栽油菜田牛繁缕的出苗规律及在田间的种群动态，结合除草3,1筛选进一步探讨了其控制策略。结果表明，牛繁缕在田间的出苗高峰在油菜移栽后3周左右，出苗量达117．0株／m^2。占整个生育期出苗数量539．0株/m^2的21．71％。其种群数量在12月中旬左右达到最大值407．8株／m^2，累计出苗数量占全生育期的82．19％，这段时期是控制牛繁缕发生危害的关键时期。茎叶处理荆高特克和土壤处理荆高渗异丙隆对牛繁缕均具有较好的防除效果，施药后第60天的防效仍维持在95％以上，并且对油菜株高、角果数及产量无不良影响。

The occurrence and control strategy of Malachium aquaticum in transplanted rape fields in Hubei Province

Malachium aquaticum (L.)Fries is a worst weed in rape fields. The emergence and population dynamics of M.aquaticum in transplanted rape fields was studied by survey of permanent quadrats and random quadrats, and field trials for herbicide screening were further conducted to develop the control strategy. The results showed that M.aquaticum reached the peak of emergence 3 weeks after rape transplanted, and the instant seedling amount was 117.0 plant/m2, accounted for 21.71% of its total seedling number (539.0 plant/m2). In mid December, the population of M.aquaticum reached the highest density of 407.8 plant/m2 and the cumulative emergence number was 82.19% of its total. This period was the critical time for control of M.aquaticum.Both foliage applied herbicides benazolin-ethyl and soil applied herbicides isoproturon had good control effects on M.aquaticum, the efficacy maintained over 95% 60 days after treatment and they had no side effects on the plant height, pod number and oilseed yield.