莼菜叶斑病的防治药剂研究

The Fungicides to Control the Leaf Spot Disease of Brasenia schreberi

莼菜作为绿色蔬菜珍品,是石柱出口及农民致富的支柱产业之一,而莼菜叶斑病在当地的发生危害越来越严重。本研究通过室内平板筛选和田间小区试验,获得对莼菜叶斑病有较好防效的杀菌剂。研究结果表明,戊唑醇、苯醚甲环唑、苯甲·丙环唑、吡唑醚菌酯的平板抑菌效果较好,对病原菌的生长抑制率可达75%;而吡唑醚菌酯的田间防效最好,3次用药后8天、16天对莼菜叶斑病的相对防效为43.63%和47.96%,并且对植株生长未见影响。以上结果表明,吡唑醚菌酯可以作为防治莼菜叶斑病的备选药剂。

Brasenia sehreberi, precious green vegetable, is one of the riching pillar industries of peasants to vegetable exporting and gain foreign currency in Shizhu, Chongqing, while the leaf spot disease of B. sehreberi damage oceurred and becoming more and more serious. In this study, we carried out the in-vitro antifungal activities testing and plot experiment for an effective fungicide to control the disease. It was showed with antagonistic aetivity on PDA plates that the growth of the pathogen was inhibited by tebuconazole, difenoconazole, difenoconazole ~ propiconazole and pyraclostrobin, the mycelial colony growth inhibiting rate reached 75%. The field control efficacy of pyraclostrobin on the leaf spot disease was best. The average relative control effects were 43.63% and 47.96%, respeetively, on 8 days and 16 days after the third fungicides application. All fungicides did not present considerable phytotoxicity symptoms. These results suggested that pyraclostrobin was a eandidate fungicide to control the leaf spot disease of B. sehreberi.