New biofumigation-based approaches to sustainable control of soil-borne pathogens

自从广谱化学熏蒸剂甲基溴停用以来，黄萎病等土传病原菌的控制已成为英国园艺的主要问题。先前的一个项目涉及烟草控制组织调查生物熏蒸的绿色作物作为甲基溴的替代品。种植和整合生物熏蒸作物被证明是困难的，但油菜籽粕土壤改良剂和薰衣草副产品对草莓黄萎病具有很高的防治效果。前者中的各种异硫氰酸酯和后者中的单萜类化合物被鉴定为活性化合物。该项目将利用这一知识开发新的生物熏蒸产品，用于控制土传疾病，特别是草莓黄萎病，但有可能应用于更广泛的作物，包括树莓、马铃薯和棉花。首先，将采用微胶囊化技术开发适合种植者使用的薰衣草和递送系统中的生物杀菌萜类化合物的缓释制剂。其次，将研究生产一种新型的薰衣草废料颗粒配方的可能性，作为有机种植者的替代方案。这些和油菜籽粕产品将在实验室和几个田间地点进行单独和联合使用对草莓黄萎病的疗效评估。还将确定它们对其他土壤传播病原体和非目标生物的影响。该项目将为在不同水平的病原体接种和不同的土壤水分条件下在实践中使用这些新产品提供优化策略。

Control of soilborne pathogens such as Verticillium wilt has become a major problem in UK horticulture since withdrawal of the broad-spectrum chemical fumigant methyl bromide. A previous project involving the RTO's investigated biofumigant green crops as replacements for methyl bromide. Cultivation and incorporation of biofumigant crops proved difficult, but a brassica seed meal soil amendment and lavender byproducts were highly effective against Verticillium wilt in strawberry. Various isothiocyanates in the former and monoterpenoid compounds in the latter were identified as the active chemicals. This project will exploit this knowledge to develop novel biofumigant products for control of soilborne diseases, particularly Verticillium wilt in strawberry, but with potential application to a much wider range of crops including raspberry, potato and cotton. Firstly, microencapsulation technology will be adapted to develop a slow-release formulation of the biocidal terpenoid compounds in lavender and delivery systems appropriate for use by growers. Secondly, the possibility of producing a novel, pelletised formulation of lavender waste will be investigated as an alternative for organic growers. These and the brassica seed meal product will be evaluated in the laboratory and in several field sites for their efficacy against Verticillium wilt in strawberry, alone and in combination. Their effects on other soil-borne pathogens and non-target organisms will also be determined. The project will provide optimised strategies for using these new products in practice under different levels of pathogen inoculum and various soil moisture conditions.