大麦与谷类科学

丙草胺作为一种水稻田常用除草剂，近年来广泛应用于小麦田杂草的防治。为探究丙草胺对沿海地区4个主栽小麦品种种子萌发及其幼苗生长的影响，本试验采用小杯法以蒸馏水和3、30、300、3 000、30 000 mg/L丙草胺分别处理扬麦34、扬麦35、淮麦44和淮麦66。结果表明，小麦与丙草胺直接接触，浓度控制在300 mg/L以内对扬麦34、扬麦35种子萌发影响较小，种子发芽率可以达到90%以上。综合分析发芽率、发芽势、发芽指数和活力指数得出，丙草胺更适用于扬麦34和扬麦35田块的杂草防治，淮麦44和淮麦66对丙草胺较为敏感。分析小麦幼苗生长指标发现，当丙草胺浓度为300 mg/L时，对小麦根长、根质量、苗长以及苗质量的生长抑制率均高于50%，因此丙草胺在麦田苗前施用不宜过晚。

Pretilachlor is a conventional herbicide for paddy fields, but in recent years it has also been widely applied to wheat fields for controlling weeds. This study was aimed to explore the effects of pretilachlor on the seed germination and seedling growth of four wheat varieties commonly planted in coastal areas, namely, Yangmai 34, Yangmai 35, Huaimai 44, and Huaimai 66, using the petri dish test. Plants of each variety were treated with pretilachlor at the concentrations of 3,30, 300, 3 000, and 30 000 mg/L, with distilled water serving as the control. The results showed that when wheat seeds were in direct contact with pretilachlor at a concentration of not more than 300 mg/L, Yangmai 34 and 35 both had a germination rate above 90%. The comprehensive analysis of its effects on germination rate, germination potential, germination index, and vitality index indicated that pretilachlor is suitable for weed control in the fields of Yangmai 34 and Yangmai 35, but not in those of Huaimai 44 and Huaimai 66, which are more susceptible to pretilachlor.The analysis of the seedling growth indexes after germination demonstrated that the application of pretilachlor at the concentration of300 mg/L led to the growth inhibition rates of wheat root length, root weight, seedling length, and seedling weight all exceeding 50%.Therefore, pretilachlor should not be applied too late at pre-emergence stage.