棘孢木霉可湿性粉剂研制及杀菌活性测定

以棘孢木霉分生孢子粉、发酵液冻干粉为有效成分制备混配杀菌剂。在测定助剂对棘孢木霉生物活性的基础上,利用正交试验设计法测定助剂对制剂性能的影响,进一步确定助剂种类和含量;通过机械粉碎法将棘孢木霉分生孢子粉、发酵液冻干粉与助剂混合配比加工成可湿性粉剂。室内离体试验法测定棘孢木霉分生孢子粉和发酵液冻干粉不同配比的制剂对油菜菌核病菌抑菌活性,获得最佳比例,并将其加工成可湿性粉剂。结果表明:棘孢木霉孢子粉和发酵液冻干粉可湿性粉剂最佳配比(质量比)为1∶1,润湿分散剂为1% Morwet EFW、5% TERWET 1010、5% Morwet D425、7%木质素磺酸钙;紫外保护剂为0.3%纳米氧化锌,以硅藻土为载体补足100%。该配方可湿性粉剂的孢子萌发率为88.57%,质量悬浮率达81.79%,孢子悬浮率80.12%,润湿时间10 s,平均粒径27 μm,符合商品制剂的标准。室内生物测定结果表明,不同混配比例制剂均有一定的增效作用,但该配比可湿性粉剂增效作用最为显著,其中1 600倍液对油菜菌核病菌防治效果比孢子粉、发酵液冻干粉单剂分别高21.67%和12.09%,抑制率范围为64.17%～88.67%。该制剂属于环境友好型绿色农药,为农林植物病害的生物防治提供了一种新生防材料。 

Preparation and fungicidal bioactivity of wettable powder formulations of Trichoderma asperellum

We prepared microbiological fungicide using conidial germination powder and freeze-dried fermentation broth powder of Trichoderma asperellum in this study. Based on measuring the bioactivity of primary adjuncts to T. asperellum, the effects of adjuncts on formulation properties were further tested according to orthogonal experimental design, and then the optimal species and contents of the adjuncts were finally determined. The wettable powder was formulated with a Muller mixer to blend conidial germination and freeze-dried fermentation broth powder of T. asperellum and adjuncts. The inhibitory activities of wettable powder formulation to Sclerotinia sclerotiorum with different ratios of conidial germination to freeze-dried fermentation broth powder of T. asperellum were evaluated. The results showed that the optimal mass ratio of conidial germination to freeze-dried fermentation broth power of T. asperellum in the wettable powder formulation was 1∶1, and the wetting dispersant was composed of 1% Morwet EFW, 5% TERWET 1010, 5% Morwet D425 and 7% calcium lignosulfonate, using 0.3% nano zinc oxide as UV protectants and diatomite as carrier to make up 100%. The conidial germination was 88.57%, mass suspension percentage was 81.79%, conidial suspension percentage was 80.12% and average particle size was 27 μm, and the wetting time for the formulation was10 s, which accorded with the standard for commercial formulations,i.e., small particle size, high suspensibility and good shelf life. All different mixed formulations had different synergistic effects, but 1∶1 ratio of formulation was significantly synergistic. The wettable power formulations (1 600×) containing both conidial germination and freeze-dried fermentation broth power had 21.67% and 12.09% higher control efficacy to S. sclerotiorum than that of wettable powder formulations containing only conidial or freeze-dried fermentation broth power. The inhibition of wettable power formulation to S. sclerotiorum ranged from 64.17% to 88.67%. Therefore, this formulation is an environment-friendly green pesticide,and our study provides a new bio-fungicide in biological control of plant diseases in agriculture and forestry.