Cook Phillip J, Landschoot Peter J, Schlossberg Maxim J
Department of Crop and Soil Sciences, The Pennsylvania State University, University Park 16802.
Plant Dis. 2009 Aug;93(8):809-814. doi: 10.1094/PDIS-93-8-0809.
Pythium aphanidermatum and other Pythium spp. cause Pythium blight of turfgrasses in the United States. Phosphonate fungicides suppress Pythium blight when applied preventatively, but efficacy may vary with product, rate and timing of application, and host species. The objectives of this study were to assess the inhibitory effects of phosphorous acid on Pythium spp. in vitro, and determine if active ingredient and formulation of phosphonate fungicides provide similar levels of Pythium blight suppression on perennial ryegrass and creeping bentgrass when applied at equivalent rates of phosphorous acid. Phosphorous acid EC values (effective concentration that reduces mycelial growth by 50%) for P. aphanidermatum isolates ranged from 35.6 to 171.8 μg/ml. EC values for isolates of six other Pythium spp. were between 38.7 and 220.8 μg/ml. In 2004 and 2005, all phosphonate treatments provided significant suppression of Pythium blight symptoms on creeping bentgrass and perennial ryegrass relative to the untreated control. No differences in percentage of blighted turf occurred among phosphonate treatments when applied at equivalent rates of phosphorous acid in either year of the study, regardless of active ingredient, formulation, or turfgrass species.
瓜果腐霉及其他腐霉属物种在美国会引发草坪草的腐霉疫病。膦酸酯类杀菌剂在预防性施用时可抑制腐霉疫病，但效果可能因产品、施用量和施用时间以及寄主物种而异。本研究的目的是评估亚磷酸对腐霉属物种的体外抑制作用，并确定当以等量亚磷酸施用时，膦酸酯类杀菌剂的活性成分和剂型对多年生黑麦草和匍匐翦股颖的腐霉疫病抑制水平是否相似。瓜果腐霉分离株的亚磷酸EC值（使菌丝体生长减少50%的有效浓度）范围为35.6至171.8微克/毫升。其他六种腐霉属物种分离株的EC值在38.7至220.8微克/毫升之间。在2004年和2005年，相对于未处理对照，所有膦酸酯处理对匍匐翦股颖和多年生黑麦草的腐霉疫病症状均有显著抑制作用。在研究的任何一年中，当以等量亚磷酸施用时，无论活性成分、剂型或草坪草物种如何，膦酸酯处理之间的草坪枯萎百分比均无差异。
