防治玉米茎腐病的一种新型木霉菌复合种衣剂

主要由禾谷镰刀菌引起的玉米茎腐病是一种重要的土传病害并能导致玉米严重减产。本研究通过筛选拮抗木霉菌,优化发酵工艺与改进配方,研制出一种新的木霉菌剂,同时为了提高防治的稳定性与持效性,筛选出了几种低毒的化学农药,并把它们加入到木霉菌种衣剂中配制成一种复合种衣剂。试验结果显示,无论是单一木霉菌种衣剂还是复合种衣剂都能有效地控制玉米苗期茎腐病,其中用木霉菌ZJSX5003菌株制成的种衣剂对病害的防效最高可达98.50%,并且对玉米种子的胚根、胚芽生长促进作用最大。同时,我们发现用木霉菌发酵液浸种6 h和将发酵液稀释50倍是促进玉米幼苗生长的最佳条件。此外,我们发现30%敌委丹、35%满适金和20%辛硫磷对于木霉菌的生长无抑制作用,而且木霉菌与35%满适金复合后对茎腐病有最高的防效且达到83%。

A Novel Trichoderma-Based Seed Coating Agent in Controlling Maize Seedling Stalk Rot

Maize seedling stalk rot caused mainly by Fusarium graminearum is an important soil borne disease and can result in significant yield loss.In this study,a new Trichoderma-based seed coating agent was formulated by screening antagonistic Trichoderma strain,optimizing fermentation process and improving formulation.Meanwhile for ensuring the stability and lasting effect of disease control,several low toxic chemical fungicides were selected,and some of these were added into the Trichoderma-based seed coating agent(TSCA)to develop a new composite seed coating agent(CSCA).Results suggested that Trichoderma ZJSX5003 showed the best disease control effect(98.5%),and it also had the best promoting effect on maize germ and radicle growth.Meanwhile,we found that 6 h seed immerging time and 50 times dilution of ZJSX5003 fermentation broth were the optimal conditions for maize seedling growth.Besides,we found that 30% difenoconazole,35% metalaxyl-m+fludioxonil and 20% phoxim EC had no inhibition effect on Trichoderma growth,and Trichoderma composited with 35% metalaxyl-m+fludioxonil had the highest control effect on stalk rot(83%).