鸭舌草生物学特性及治理对策

Biological Properties of Monochoria vaginalis and Its Control Strategy

对稻田恶性杂草鸭舌草的植物学和生物学特性及其对水稻产量的影响等进行了室内外系统研究。结果表明 ,鸭舌草分布广泛 ,有较长的生理休眠期 ;种子在 1cm土层内萌发最好 ,在 2～ 4cm土层内则出苗极少 ;土壤饱和水分条件有利于种子萌发 ;生长发育的最适温度为 2 0～ 2 5℃ ,土壤水分饱和或薄水条件下生长最好 ,肥料充足则生长迅速 ;鸭舌草在直播稻田、抛栽稻田和移栽稻田均有明显的出草高峰 ;1m2 定植鸭舌草 80株 ,稻、草共生 4 0d水稻减产 14 0 % ,全生育期稻、草共生 ,水稻减产达 19 5 % ;鸭舌草与水稻竞争的临界密度为 1m2 6 0株 ,水稻减产达10 0 %以上。生产中宜采取水旱轮作、减少追肥、科学治虫、保护天敌、促进水稻早生快发 ,并以群体优势控草、稻田养鸭 。

Monochoria vaginalis is a widespread weed in paddy field.The life cycle of M. vaginalis closely aligns with the growing season of rice and therefore causes severe competition with rice.A series of experiments were conducted to evaluate the biological properties of M.vaginalis and its effects on rice yield.The optimum temperature for growth and development of M.vaginalis ranged from 20～25℃. Seed germinability of Monochoria vaginalis inhanced rapidly under the saturated moisture condition and the condition that soil layer was within 1 cm.Emergence of M.vaginalis had a summit period in directed seeding,throwing and transplanting paddy field. M.vaginalis was allowed to grow until 40 d after transplantation and at the whole growing season and resulted in yield reduction by 14% and 19 5% respectively.The critical density to severe competition with rice was 60 plants/m 2.These findings established the approaches to control M.vaginalis comprehensively which included rotation between dryland crop and paddy rice,raise ducks in paddy,the development of more competitive rice population through rational fertilizer application,protecting natural enemy and applying herbicides.