The ability to quantify inoculum levels of the soilborne fungal pathogen Verticillium dahliae in field soil is essential for understanding potential disease pressure of Verticillium wilt in cotton and for making informed management decisions. Several semi-selective media and techniques for pathogen isolation have been developed for determining the inoculum levels of V. dahliae present in soil. The objective of this study was to gather data on soil plating techniques, media, sampling depths, and times of sampling for the detection and quantification of V. dahliae in field soils, in order to develop a V. dahliae isolation protocol for Australian cotton-growing soils. Two soil plating techniques (dilution plating or ‘wet plating’, and direct spreading by hand or ‘dry plating’) on four semi-selective media (Sorenson’s NP-10, potato dextrose agar, and acidified versions of each) were compared for their efficacy in quantifying soil inoculum as germinated microsclerotia propagules per gram soil. Soil was sampled from three depths to examine the vertical distribution of the fungus and so determine the ideal sampling depth. Field soil sampling was conducted pre-planting and post-harvest to examine differences in inoculum with sampling time. Based on the results of this study, a soil sampling protocol has been developed for Australian cotton farms that includes sampling soil before planting, at a depth of 2–24 cm, and using the direct dry plating method on Sorenson’s NP-10 media.

定量田间土壤中土壤传播的真菌病原体黄萎病菌接种量的能力对于了解棉花黄萎病的潜在病害压力和做出明智的管理决策至关重要。已经开发出几种用于病原体分离的半选择性培养基和技术，用于确定土壤中存在的大丽花弧菌的接种水平。这项研究的目的是收集土壤平板技术，培养基，采样深度和采样时间的数据，以检测和定量田间土壤中的大丽花，以开发大丽花。澳大利亚棉花种植土壤的隔离协议。比较了在四种半选择培养基（Sorenson NP-10，马铃薯葡萄糖琼脂和每种酸化版本）上的两种土壤镀层技术（稀释镀层或“湿式镀层”，以及直接直接铺展或“干式镀层”）每克土壤中以萌发的微菌核繁殖体定量土壤接种物的功效。从三个深度对土壤进行采样，以检查真菌的垂直分布，从而确定理想的采样深度。在种植前和收获后进行田间土壤采样，以检查接种物随采样时间的差异。根据这项研究的结果，已经为澳大利亚棉花农场开发了土壤采样方案，包括在种植前在2–24 cm深度采样土壤，