Sensitivity to Azoxystrobin Among Isolates of Uncinula necator: Baseline Distribution and Relationship to Myclobutanil Sensitivity

Plant Disease
Francis P Wong, W F Wilcox

Abstract

Two hundred fifty-six single-conidial chain isolates of Uncinula necator were assayed for their sensitivity to azoxystrobin and myclobutanil. These isolates were collected from two sites in New York in 1999: an "organic" vineyard where no synthetic fungicides have been used (baseline population) and a commercial vineyard having a history of compromised powdery mildew control with myclobutanil (demethylation inhibitor [DMI]-resistant population). Mean coefficients of variance for a leaf disk assay used to test fungicide sensitivities were 31% for azoxystrobin and 41% for myclobutanil. Baseline ED50 values ranged from 0.0037 to 0.028 μg/ml (mean 0.0097μg/ml) for azoxystrobin and from 0.0049 to 0.69 μg/ml (mean 0.075 μg/ml) for myclobutanil. A shift in the mean ED50 value for azoxystrobin to 0.018 μg/ml was observed in the DMI-resistant population; with the strongest shift observed for isolates collected from vines treated exclusively with myclobutanil (0.024 μg/ml). For the 256 tested isolates, there was a moderate, but statistically significant, correlation between azoxystrobin and myclobutanil sensitivities (R2 = 0.36, P < 0.001). Tests with three other strobilurin fungicides (kresoxim-methyl, pyraclostrobin, and trifloxystrobi...Continue Reading

References

Apr 1, 1993·Pediatric Hematology and Oncology·O B EdenA E Emery
Apr 15, 1997·FEMS Microbiology Letters·T Joseph-Horne, D W Hollomon
Jul 22, 1998·Journal of Neuroscience Research·M A ElwanN Sakuragawa
Aug 24, 2000·Fungal Genetics and Biology : FG & B·G Del SorboM A De Waard

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Citations

Feb 14, 2006·Pest Management Science·Maarten A de WaardLute-Harm Zwiers
Jan 24, 2019·Plant Disease·Mitchell J Bauske, Neil C Gudmestad
Jan 24, 2019·Plant Disease·Mitchell J BauskeNeil C Gudmestad
Oct 24, 2008·Phytopathology·Lisa Emele Hoffman, Wayne F Wilcox
Jan 1, 2012·Plant Disease·Jeneylyne F ColcolAnton B Baudoin
Sep 23, 2020·Microorganisms·Alejandra Vielba-FernándezDolores Fernández-Ortuño
Apr 1, 2007·Plant Disease·Greg English-LoebWayne Wilcox
Feb 1, 2004·Plant Disease·J S PascheN C Gudmestad
Oct 16, 2010·Pest Management Science·Marie-Cécile DufourMarie-France Corio-Costet

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