稻田双穗雀稗生物学特性、发生危害及防控

Biological Characteristics,Occurrence,Damage and Control of Paspalum distichum in Rice Field

2010年对鄱阳湖区东北部、中部、西南部三地的中晚稻田抽样调查表明,该区稻田双穗雀稗的发生频率为70.69%～86.21%,发生密度为0.12～0.29株/m2。对机插晚稻田间双穗雀稗的危害损失测定表明,水稻产量损失与双穗雀稗密度、植株鲜重有显著的正相关性,在产量损失构成因素中以有效穗数、穗实粒数影响占主导;每1.26 m2内有双穗雀稗1、2、3、5株,产量损失率分别达到17.24%、27.33%、49.13%、57.78%,每株双穗雀稗可使水稻减产11.0%～17.0%。提出了耕前灭生除草、农艺措施控草、苗期使用选择性除草剂的综合防控技术。

The middle and late rice fields in the northeast,center and southwest part of the Poyang Lake area were sampled and surveyed in 2010,the results indicated that the occurrence frequency of Paspalum distichum L.was from 70.69% to 86.21% in the rice field,and the occurrence density of this weed was 0.12~0.29 plants per square meter.The rice yield loss caused by Paspalum distichum in mechanically-transplanted late rice fields was determined,it was found that the rice yield loss had obvious positive correlation with the density and plant fresh weight of Paspalum distichum,and the number of productive ear and the filled grains per ear played main role in yield loss components.When there were 1,2,3 or 5 plants Paspalum distichum in 1.26 square meter rice field,the corresponding rice yield loss rate reached 17.24%,27.33%,49.13% or 57.78%,and one plant Paspalum distichum per square meter could reduce rice yield by 11.0%~17.0%.The paper put forward the following integrated techniques for the control of Paspalum distichum： weeding before plough,controlling the weed by agronomic measures,using selective herbicides at seedling stage.