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ARS Home » Pacific West Area » Wenatchee, Washington » Physiology and Pathology of Tree Fruits Research » Research » Publications at this Location » Publication #340441

Research Project: Utilization of the Rhizosphere Microbiome and Host Genetics to Manage Soil-borne Diseases

Location: Physiology and Pathology of Tree Fruits Research

Title: Management of bull’s eye rot using preharvest and postharvest fungicides

item SIKDAR, PARAMA - Washington State University
item Mazzola, Mark

Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 5/26/2017
Publication Date: 12/1/2017
Citation: Sikdar, P., Mazzola, M. 2017. Management of bull’s eye rot using preharvest and postharvest fungicides. Phytopathology. 107(Suppl.5), 192.

Interpretive Summary:

Technical Abstract: Neofabraea perennans and N. kienholzii are major causal pathogens of bull’s eye rot in apple in Eastern WA. These fungi cause significant economic loss to the Washington State apple industry and have been listed as quarantine pathogens. Previous experiments indicate that fungicide treatments containing thiabendazole and thiophenate methyl provide effective bull’s eye rot control, however use of this treatment is not recommended due to the potential for resistance development in populations of Penicillium spp. Hence, the objective of this research was to screen newer commercially available fungicides, possessing multiple active chemistries, for bull’s eye rot control. Fungal sensitivity and disease control efficacy were tested in vitro and in orchard trials, respectively. Results from these trials with Neofabraea spp. isolates suggest that fungicide containing fluopyram and trifloxystrobin may inhibit Neofabraea spp. in vitro at a level equivalent to that of thiabendazole. Neofabraea spp. isolates resistant to preharvest fungicide difenoconazole and cyprodinil, and postharvest fungicide pyrimethanil were identified in the trial. Field trials utilizing preharvest sprays and postharvest drenches indicate that preharvest applications two weeks before harvest with fungicide containing fluopyram and trifloxystrobin is most effective in controlling postharvest bull’s eye rot in storage.