McManus P S, Best V M, Voland R P, Leininger B L
Department of Plant Pathology, University of Wisconsin, Madison 53706.
Plant Dis. 1999 May;83(5):445-450. doi: 10.1094/PDIS.1999.83.5.445.
The efficacy of fungicides in controlling cottonball disease of cranberry was tested during 1996 to 1998 at three locations in Wisconsin. For some fungicides, the efficacy of four applications, two each during shoot elongation and bloom, was compared with two applications during bloom only. Spraying twice during bloom was as effective in controlling secondary infection as spraying twice during shoot elongation plus twice during bloom. Azoxystrobin, cyprodinil, and propiconazole were equally effective. None of the treatments affected yield, fruit retention, or berry weight compared with the controls. Sensitivity of M. oxycocci, the cottonball pathogen, to fenbuconazole and propiconazole was tested in vitro by comparing the distributions of ED values of populations collected from three sites that differed in previous exposure to fungicides. Median ED values for fenbuconazole were significantly greater at sites where sterol demethylation inhibitor fungicides had been used compared with a site where fungicides had never been used, but median ED values for propiconazole did not differ among sites. There was no correlation between the sensitivities to fenbuconazole and propiconazole. The data will form the basis of recommendations aimed at delaying the onset of fungicide resistance and will provide a baseline for monitoring resistance to fenbuconazole and propiconazole in populations of M. oxycocci in the future.
1996年至1998年期间，在威斯康星州的三个地点对杀菌剂防治蔓越莓棉球病的效果进行了测试。对于某些杀菌剂，比较了四次施药（在新梢伸长和开花期各施药两次）与仅在开花期施药两次的效果。在开花期施药两次对控制二次感染的效果与在新梢伸长和开花期各施药两次的效果相同。嘧菌酯、嘧菌环胺和丙环唑的效果相同。与对照相比，没有一种处理影响产量、果实留存率或浆果重量。通过比较从三个先前接触杀菌剂情况不同的地点采集的病原菌群体的ED值分布，在体外测试了棉球病病原菌卵形小红莓病菌对苯氟康唑和丙环唑的敏感性。与从未使用过杀菌剂的地点相比，在使用过甾醇脱甲基抑制剂杀菌剂的地点，苯氟康唑的中位ED值显著更高，但丙环唑的中位ED值在各地点之间没有差异。对苯氟康唑和丙环唑的敏感性之间没有相关性。这些数据将构成旨在延缓杀菌剂抗性出现的建议的基础，并将为未来监测卵形小红莓病菌群体对苯氟康唑和丙环唑的抗性提供基线。
