几丁质和杀菌剂对生物防治菌生长及其防治棉花病害效果的影响

INFLUENCE OF CHITIN AND CHEMICAL FUNGICIDES ON GROWTH AND ACTIVITY OF BIOCONTROL AGENTS AGAINST COTTON DISEASES

研究了化学杀菌剂对木霉菌生长的影响 ,探讨了几丁质添加物对绿色木霉菌菌株 L R、LTR- 2、哈茨木霉菌菌株 Q1、Q2和粉红粘帚霉菌菌株 GL R防治棉花病害效果的影响。多菌灵、苯菌灵和甲基硫菌灵在 1.66μg/ ml时可以完全抑制 Q1和 Q2的生长 ,但在 2 .68μg/ ml时才能完全抑制 LR和L TR- 2的生长。几丁质添加物使 L TR- 2和 Q1防治棉花立枯病的效果完全丧失 ,但是能使 L R从没有防治效果提高到防治效果为 34.6% ,而对粉红粘帚霉菌的防治效果没有显著影响 ;对于防治棉花黄萎病来说 ,几丁质添加物使木霉菌 LR、LTR- 2和 GL R的防治效果降低 ,但是提高了 Q1的防治效果 ;对于防治棉花枯萎病来说 ,几丁质添加物能提高所有测定菌株的防治效果。说明不同的生物防治菌株、添加物和病害组合对于获得良好的防治效果是重要的。

This paper deals with the influence of chemical fungicides and chitin additives on the growth and the biocontrol activity of Trichoderma viride strain LR and LTR 2, T. harzianum strain Q1 and Q2, and Gliocladium roseum strain GLR against cotton diseases. It was found that carbendazim, benomyl and thiophanate methyl completely inhibited the growth of Q1 and Q2 at a concentration of 1.66 μg/ml, and LR and LTR 2 at a concentration of 2.68 μg/ml. In controlling cotton damping off (caused by Rhizoctonia solani ), chitin additives completely eliminated the biocontrol activity of LTR 2 and Q1, but raised the control efficacy of LR from nil to 34.6%, while showing no significant effect on the biocontrol activity of GLR. In controlling cotton verticillium wilt (caused by Verticillium dahliae ), chitin additives reduced the efficacy of LR, LTR 2 and GLR, but increased that of Q1. As for control fusarium wilt of cotton (caused by Fusarium oxysporum f. sp. vasinfectum ), chitin additives increased the efficacy of all tested strains. The results indicated that combinations of different biocontrol agents, additives and diseases were important in getting ideal biocontrol results.