【摘要】 为明确不同氮肥施用量对杀菌剂防治小麦白粉病效果的影响,于2016年-2017年、2017年-2018年和2018年-2019年3年度在河北廊坊研究了正常氮肥施用水平和减施氮肥水平下25%乙嘧酚悬浮剂(7个梯度)对田间小麦白粉病的防效。结果表明,不同的氮肥施用量对药剂防治病害的效果有一定影响,在相同药剂用量下减施氮肥处理(N2)药剂的防效大多要显著高于正常施氮处理(N1)。对3年度不同氮肥施用水平下药剂用量与病情指数或防效的关系模型以及随机系数回归模型比较分析发现,其模型的斜率无显著性差异,截距大部分有显著性差异。通过防效混合效应模型构建的不同分位数模型(10%、30%、50%、70%、90%),获得了2种氮肥施用水平下不同用量的25%乙嘧酚悬浮剂防治田间小麦白粉病的效果。同时,利用防效的关系模型计算了2种氮肥施用水平下25%乙嘧酚悬浮剂对小麦白粉病防效和药剂用量对照表,为氮肥减施情况下药剂用量的合理选用提供了科学依据。更多还原

【Abstract】 To explore the effects of different nitrogen application levels on control efficacies of fungicide to wheat powdery mildew, field experiments on the control efficacies of ethirimol 25% SC(7 active ingredient dosages) to wheat powdery mildew under normal nitrogen fertilizer level and reduced nitrogen fertilizer level were conducted during wheat growing seasons in Langfang city, Hebei province in 2016-2017, 2017-2018 and 2018-2019. The results showed that different nitrogen fertilizer application levels affected the control efficacy of ethirimol 25% SC. Under the same active ingredient dosage of ethirimol 25% SC, most of the control efficacies under reduced 1/2 or 1/3 nitrogen fertilizer application level(N2) were significantly higher than normal nitrogen fertilizer application level(N1). A comparative analysis of the relationship models between active ingredient dosages and disease indexes/control efficacies, as well as the random coefficient regression models at different nitrogen fertilizer application levels in the three growing seasons were conducted. The results showed that there was no significant difference in slopes, but significantly different for most of the intercepts of models. 10%, 30%, 50%, 70% and 90% quantile models of disease index or control efficacy were established based on the random mixed effect model, and the control efficacy ranges of ethirimol 25% SC under different active ingredient dosage at two nitrogen fertilizer application levels were obtained by these quantile models. Meanwhile, the reference table of the control efficacies and the active ingredient dosages of ethirimol 25% SC under two nitrogen application levels were established according to the relational models of control efficacy, which can provide a scientific basis for the rational selection of active ingredient dosages of ethirimol 25% SC in the case of reducing nitrogen fertilizer application in the fields.更多还原