寡雄腐霉与烯酰吗啉互作防治葡萄霜霉病和替代部分化学药剂减量用药应用

Inhibitory effect of Pythium oligandrum interaction with dimethomorph and the application of chemical decrement on grape downy mildew

利用室内与室外传统生物测定方法,结合诱导抗病性生理测定方法进行试验。明确寡雄腐霉用药时期;研发生化互作组合,明确增效作用机制;制定生化互作减量用药防控技术规程。结果表明寡雄腐霉预防葡萄霜霉病最佳时期为发病前1个月,连续喷雾用药3～4次,间隔期10～15 d。明确寡雄腐霉对叶片β-1,3葡聚糖酶产生具有诱导作用;研发出协同增效的生防菌剂与化学杀菌剂组合烯酰吗啉+寡雄腐霉(或者再加上100%硅氧烷化合物,此时同样防效下喷雾使用药液量仅为组合的40%)。寡雄腐霉与化学杀菌剂烯酰吗啉互作后,植株诱导抗病作用增强。制定以生防菌替代和高效合理化学用药为关键技术的减量用药防控葡萄霜霉病的综合体系,确定用药规程中药剂的使用类别、次序、排列和组合。

To clarify the the time of the application of Pythium oligandrum and develop the biochemical interaction combinations and their synergistic mechanism; then to establish the technological rules of biochemical interaction for reducing chemical fungicide. The traditional indoor and outdoor bioassays, combined with methods to study the pphysiological mechanism on induced resistance were used in this study. Results showed that the best time for the prevention of grape downy mildew with Pythium oligandrum was one month before the disease occurrence. The number of continuous spraying times is three to four with the interval of ten to fifteen days. β-1, 3-glucanase was induced in grape leaves by Pythium oligandrum. The new synergistic combinations of fungicide and biological control agent ＂dimethomorph ＋ Pythium oligandrum（ or plus 100% siloxane compounds, the spray dosage was only 40% of the combination with the same control effect）were found for controlling grape downy mildew. Resistance effect induced by Pythium oligandrum was increased when combined with dimethomorph. The integrated prevention and control system of grape downy mildew which was mainly based on biological agent and rational and efficient use of fungicide was established. The categories, order, arrangement and combination of fungicides were determined in the rule.