郭云忠 胡杰 李思娟 闫明杰 李文文 胡小平

摘要：通过田间调查和资料分析，对陕西关中灌区小麦田杂草的种类、出苗规律和防治指标进行研究。结果表明，关中灌区小麦田杂草有15种，隶属8科15属，其中优势杂草有播娘蒿、荠菜、婆婆纳、猪殃殃、节节麦等5种，一般杂草有野燕麦、宝盖草、田紫草等3种，其余为区域性杂草。小麦播种后5 d陆续有杂草出土，在11月上中旬（小麦3～4叶期），占总草91%的杂草均已出苗，是生产中防治用药的最适宜时间。关中灌区麦田杂草密度（x）与小麦产量损失率（y）呈极显著正相关关系（r=0.992 0），其关系式为y=0.166 0x-0.906 7。按照目前关中灌区小麦的产量、价格、除草成本及效果，在本研究的草相条件下杂草的防治指标为30株/m2，应在冬前小麦3～4叶期进行防除。

关键词：关中灌区;麦田杂草;发生规律;防治指标;杂草密度

中图分类号：S451.1  文献标志码：A  文章编号：1003-935X（2021）01-0038-05

Abstract：Wheat fields in Guanzhong irrigation area were survey to determine weed species，emergence patterns and control indexes. There were 15 weedspeciesbelonging to 15 genera and 8 families，among which five were dominant：Descurainia sophia，Capsella bursa-pastoris，Veronica didyma，Euphorbia pulcherrima and Aegilops tauschii;three were considered common （Avena fatua，Lamium amplexicaule and Buglossoides arvensis，and the rest were regional weeds. All weeds basically emerged at the same time when wheat was at the 3～4 leaf stage，accounting for 91% of the total grass，which is the most suitable time for prevention and treatment in production. Weed density positively correlated （r=0.992 0） with wheat yield loss rate in Guanzhong irrigation area，a relationship described by a linear relationship（y=0.166 0x-0.906 7）. According to current yield，price，weeding cost and effect of wheat in Guanzhong irrigation area，it is proposed that the weed control index is 30 plants/m2，which should be controlled at the 3～4 leaf stage of wheat before winter.

Key words：Guanzhong irrigation area;weeds in wheat fields;regularity of occurrence;economic threshold;weed density

麦田杂草是小麦生长过程中遭遇到的最主要的生物災害之一，陕西关中平原是陕西省小麦的主产区和优势生产区，这里土壤肥沃、光照充足、雨水较多，且具备灌溉条件。优越的条件也极利于杂草的生长，据文献报道，陕西省农田杂草种类多达47属74种[1]。在关中杂草发生严重的小麦田块，杂草数量多达300株/m2，与小麦争水、争肥、争阳光、争空间严重，成为小麦高产、稳产的最主要障碍。因此，及时采取有效的措施控制杂草的危害具有重要的意义。

目前农村劳动力较缺乏，这就迫使一切农事活动尽可能向省工、省力、高效方向发……