Bowers John H, Locke James C
USDA, ARS, U.S. National Arboretum, Floral & Nursery Plants Research Unit, Rm. 238, B-010A, BARC-W, Beltsville, MD 20705.
Plant Dis. 2000 Mar;84(3):300-305. doi: 10.1094/PDIS.2000.84.3.300.
Several commercial formulations of botanical extracts and essential oils are being investigated as possible alternatives to soil fumigation for control of Fusarium wilt diseases. Soil infested with Fusarium oxysporum f. sp. chrysanthemi was treated with 1, 5, and 10% aqueous emulsions of formulated extracts of clove (70% clove oil), neem (90% neem oil), pepper/mustard (chili pepper extract and essential oil of mustard), cassia (extract of cassia tree), and Banrot (a standard fungicide applied at different labeled rates) in separate experiments. Population densities of F. oxysporum f. sp. chrysanthemi were determined at 0 (before treatment), 1, 3, 7, 14, and 21 days after treatment. Treatment of the soil with 5 and 10% aqueous emulsions resulted in significant (P < 0.05) differences among treatment means at each assay date. After 3 days, pepper/mustard, cassia, and clove extracts added as 10% aqueous emulsions reduced the population density of F. oxysporum f. sp. chrysanthemi 99.9, 96.1, and 97.5%, respectively, compared with the untreated control. Neem oil extract increased the population density of F. oxysporum f. sp. chrysanthemi at all concentrations tested. Banrot did not reduce the population density of F. oxysporum f. sp. chrysanthemi in any experiment. In a second, related experiment, soil infested with Fusarium oxysporum f. sp. melonis also was treated with 1, 5, and 10% aqueous emulsions of formulated extracts, incubated in closed plastic bags for 1 week, and planted with muskmelon seeds (cv. Gold Star) in the greenhouse. Treatment of infested soil with 5 and 10% aqueous emulsions of the botanical extracts resulted in differences among treatments after 5 to 6 weeks. The pepper/mustard, cassia, and clove extracts suppressed disease development in repeated experiments (80 to 100% healthy plant stand) compared with the untreated infested soil (<20% stand). The observed reduction in the pathogen population and increased healthy plant stand in the greenhouse indicates that these extracts could have important roles in biologically based management strategies for control of Fusarium wilt diseases.
目前正在研究几种植物提取物和精油的商业配方，作为土壤熏蒸防治枯萎病的可能替代方法。用尖孢镰刀菌黄瓜专化型侵染的土壤，在不同实验中分别用丁香（70%丁香油）、印楝（90%印楝油）、胡椒/芥末（辣椒提取物和芥末精油）、桂皮（桂皮树提取物）和Banrot（一种按不同标记剂量施用的标准杀菌剂）的配方提取物的1%、5%和10%水乳液进行处理。在处理前的0天、处理后的1天、3天、7天、14天和21天测定尖孢镰刀菌黄瓜专化型的种群密度。用5%和10%水乳液处理土壤后，在每个测定日期处理均值之间存在显著（P<0.05）差异。3天后，作为10%水乳液添加的胡椒/芥末、桂皮和丁香提取物，与未处理对照相比，分别使尖孢镰刀菌黄瓜专化型的种群密度降低了99.9%、96.1%和97.5%。印楝油提取物在所有测试浓度下均增加了尖孢镰刀菌黄瓜专化型的种群密度。在任何实验中，Banrot均未降低尖孢镰刀菌黄瓜专化型的种群密度。在第二项相关实验中，用尖孢镰刀菌甜瓜专化型侵染的土壤也用配方提取物的1%、5%和10%水乳液进行处理，在封闭塑料袋中孵育1周，然后在温室中种植甜瓜种子（品种：金星）。用植物提取物的5%和10%水乳液处理受侵染土壤5至6周后，各处理之间出现差异。与未处理的受侵染土壤（<20%植株存活）相比，胡椒/芥末、桂皮和丁香提取物在重复实验中抑制了病害发展（80%至100%健康植株存活）。在温室中观察到的病原菌种群减少和健康植株存活增加表明，这些提取物在基于生物学的枯萎病防治管理策略中可能发挥重要作用。
