粉硫胶悬剂防治小麦白粉病及叶锈病试验

用四川省化工研究所新研制的粉硫胶悬剂防治小麦白粉病和叶锈病的田间试验在四川雅安进行。在小麦抽穗期,白粉病处于盛发阶段时,用45％的粉硫胶悬剂300倍液喷雾,10天后防效高达100％,21天后防效仍为94.5％,一次用药即可完全控制危害,用500倍液进行喷雾防效只能到80％,一次喷药并不能完全控制,小麦生长后期白粉病的发展。对于白粉病发展迟缓的田块,在扬花期施用粉硫胶悬剂700倍液喷撒,一次即可基本控制小麦白粉病和叶锈病的危害。试验结果表明,45％粉硫胶悬剂300倍液对于小麦白粉病和叶锈病的防治效果优于16％粉锈宁可湿性粉剂2000倍液,而用500倍的45％粉硫胶悬剂则与其相当。粉硫胶悬剂兼具内吸和保护作用,防病时间持久。

EXPERIMENT OF THE CONTROL OF WHEAT POWDERY MILDEW AND LEAF RUST WITH BAY—LETON—SULPHUR MIXTURE

Field experiment of the control of wheat powdery mildew and leaf rust was made in Yaan with 45% Bayleton-sulphur mixture, which was newly developod by sichuan Institute of Chemical Industry. When the mixture was sprayed at 300 x concentration in the heading period of wheat while the powdery mildew was at the peak of developing, the efficience of the control of diseases was 100% 10 days later, and was still 94.5% 21 days even after the applying. Therefore, one-time application at this concentration could give complete control of wheat powdery mildew. But, in the eondition above, when the concentration at 500x dilution was used, the efficience was only 80%, one-time application of the mixture could not prevent the devlopment of the powdery mildew during the late growth period of wheat. However, for the field where the powdery mildew developed rather slowly, one-time spray of the mixture at 700x concentration had a satisfactory effect against wheat powdery mildew and leaf rust. The results indicated that effects of controlling the powdery mildew and leaf rust of 45% Bayleton-sulphur at 300 x were much better than those of 15% Bayleton alone at 2000 x. The mixture used at the 500 x concentration had similar effects to 15% Bayleton. Bayleton-sulphur mixture had systemic property and protective actions.