非洲哈茨木霉AD-G4可湿性粉剂的研发及对紫花苜蓿根腐病的防效

Development of AD-G4 wettable powder and its control effect for root rot of alfalfa

摘要:

【目的】苜蓿(Medicago sativa)根腐病是苜蓿栽培过程中发生的一种较为普遍的土传性病害。非洲哈茨木霉(Trichoderma afroharzianum)具有防治苜蓿根腐病的生防潜力,故探讨其可湿性粉剂的研发和对苜蓿根腐病的防控效果。【方法】以非洲哈茨木霉AD-G4为研究对象,通过筛选可湿性粉剂的适宜载体、分散剂、湿润剂、紫外线保护剂及其最佳比例,研制AD-G4可湿性粉剂,并对苜蓿根腐病防治效果进行评价。【结果】非洲哈茨木霉AD-G4可湿性粉剂的最佳组成成分及比例为AD-G4孢子粉30%,8%湿润剂十二烷基硫酸钠,2%分散剂木质素磺酸钠,湿润剂和分散剂总用量为10%,2%的紫外线保护剂糊精,其余以载体硅藻土补足。所得制剂活菌数为1.24×10¹⁰ cfu/g,150 μm筛通过率为95%,湿润时间为32.45 s,热贮稳定性82.26%,悬浮率82.24%,pH值7.2,所有指标均达到国家标准。室内盆栽试验表明,非洲哈茨木霉AD-G4可湿性粉剂可显著降低苜蓿根腐病的发病率,防治效果达到87.58%。【结论】非洲哈茨木霉可湿性粉剂可有效防治苜蓿镰刀菌根腐病。

Abstract:

【Objective】Medicago sativa root rot is a common and important soil-borne disease that occurs widely in alfalfa cultivation. Trichoderma afroharzianum has biocontrol potential for preventing alfalfa root rot, and this study aims to discuss the control of alfalfa root rot by its wettable powder (WP).【Method】In this study, Trichoderma afroharzianum AD-G4 was selected as the research object. AD-G4 wettable powder (WP) was prepared by screening for suitable carrier, dispersant, wetting agents, and UV-protective agents, as well as their optimal ratios, and its control efficacy against alfalfa root rot was determined.【Result】The optimal composition and proportion of the T. afroharzianum AD-G4 WP were 30% AD-G4 spore powder, 8% sodium lauryl sulfate as the wetting agent, 2% sodium lignosulfonate as the dispersant (with the total amount of wetting agent and dispersant being 10%), 2% dextrin as the UV-protective agent, and the rest was filled with the carrier diatomaceous earth. The viable spore count of WP prepared under these parameters was 1.24×10¹⁰ cfu/g. The pass rate of the 150 μm sieve was 95%, the wetting time was 32.45 s, thermal storage stability was 82.26%, the suspension rate was 82.24%, and the pH was 7.2. All these indexes met the national standards. The indoor pot trail showed that the prepared T. afroharzianum AD-G4 WP could significantly reduce the incidence of alfalfa root rot, and the control efficacy reached 87.58%.【Conclusion】The obtained WP of T. afroharzianum can effectively control Fusarium root rot of alfalfa.