锌贝克、崇高和易斑净对柱花草炭疽病的防效

Control effect of zineb,diffenoconazole and prochloraz-manganese against Stylosanthes anthracnose

柱花草炭疽病Stylo anthracnose是严重影响柱花草Stylosanthes guianensis生产的主要病害之一,药剂防治是减轻该类病害的有效措施。试验结果表明:锌贝克、崇高和易斑净对炭疽菌菌落和分生孢子都有抑制作用,其中锌贝克、崇高随着稀释倍数的增加菌落抑制率降低。药剂处理后5 d,易斑净3个处理梯度的抑菌率均达到和接近100%;锌贝克700倍的抑菌率达到95.45%,崇高10 000倍的药效达到82.13%;随着3种药剂稀释倍数的增加,孢子抑制率降低,在早期的12 h锌贝克700倍、崇高10 000倍、易斑净1 500倍药液处理完全抑制了孢子的萌发。但到了36 h,除易斑净1 500倍仍保持对孢子萌发的完全抑制外,锌贝克和崇高各处理梯度的抑制率均下降,其中崇高的下降幅度最大。盆栽药效试验中3种杀菌剂的稀释倍数均与防效成反比。处理后第7天锌贝克500倍防效为40.20%。易斑净1 000倍防效为36.62%。崇高7 000倍处理的防效达到22.15%。杀菌剂盆栽试验的防效明显低于室内试验。

Stylo anthracnose is one of the main diseases to damage Stylosanthes guianensis, and chemical control is still the most effective method to reduce the damage. The research result showed that the fungal colony growth and conidia germination were inhibited by Zineb （65% WP）, Diffenoconazole （50% WP） and Prochloraz-Manganese （28% WP）, in which, the inhibitory rate of colony increased with the concentration of Zineb and Diffenoconazole. After 5 days later, the inhibitory rate reached nearly 100% under the treatment of 3 concentrations of Prochloraz-Manganese. It reached 95.45% under 700-fold diluted Zineb, and 82.13% under 10 000-fold diluted Diffenoconazole. The inhibitory rate of conidia germination was positive correlation with the concentration of 3 fungicides and it reached 100% by 700-fold diluted Zineb, 10 000-fold diluted Diffenoeonazole and 1 500-fold diluted Prochloraz-Manganese after treatment for 12 hours. However, the inhibitory rate of conidia germination of Zineb and Diffenoconazole decreased after treatment 36 hours. The relative control effect of 3 fungicides was positive correlated with the concentration, and it was 40.20% by 500-fold diluted Zineb, 36.62% by 1 000-fold diluted Prochloraz-Manganese and 22. 15% by 7 000-fold diluted Diffenoconazole after treatment for 7 days. The relative control effect of fungicide in laboratory test was obviously less than that in pot experiment.