Articles
Evaluating fungicide efficacy for wild blueberry foliar disease complex management in eastern Canada
Article number
1378_15
Pages
113 – 120
Language
English
Abstract
The wild blueberry foliar disease complex reduces yields when left unmanaged in the vegetative year of production.
This disease complex comprises blueberry leaf rust (Thekospora minima), Sphaerulina leaf spot (Sphaerulina vaccinii) and Valdensia leaf spot (Valdensia heterodoxa). Chlorothalonil adequately managed the foliar disease complex, however, it is no longer being used by many growers due to its deregistration in Canada, and imposition of crop management standards by food processors in other countries.
The objective of this study was to evaluate registered and new fungicide options for their impact on foliar diseases, leaf number and normalized difference vegetation index (NDVI). Field trials conducted in the 2021 growing season in Debert and Kemptown, Nova Scotia, consisted of 11 treatments: untreated, mefentrifluconazole, mefentrifluconazole + fluxapyroxad, mefentrifluconazole + pydiflumetofen, pydiflumetofen, pydiflumetofen + difenoconazole, prothioconazole, fluopyram + prothioconazole, prothioconazole + benzovindiflupyr, prothioconazole + pydiflumetofen and folpet.
Disease pressure was significantly greater at the Kemptown location.
At both locations prothioconazole + benzovindiflupyr recorded up to 17% greater leaf number than all other treatments, and at least 48.6% less diseased leaves per stem than the untreated.
Mean NDVI for prothioconazole with benzovindiflupyr treatment plots was 13.8 and 62% greater than the untreated at the Kemptown and Debert locations, respectively.
This study demonstrates that the tank mix of prothioconazole with benzovindiflupyr offers the greatest control of foliar diseases in wild blueberries.
This disease complex comprises blueberry leaf rust (Thekospora minima), Sphaerulina leaf spot (Sphaerulina vaccinii) and Valdensia leaf spot (Valdensia heterodoxa). Chlorothalonil adequately managed the foliar disease complex, however, it is no longer being used by many growers due to its deregistration in Canada, and imposition of crop management standards by food processors in other countries.
The objective of this study was to evaluate registered and new fungicide options for their impact on foliar diseases, leaf number and normalized difference vegetation index (NDVI). Field trials conducted in the 2021 growing season in Debert and Kemptown, Nova Scotia, consisted of 11 treatments: untreated, mefentrifluconazole, mefentrifluconazole + fluxapyroxad, mefentrifluconazole + pydiflumetofen, pydiflumetofen, pydiflumetofen + difenoconazole, prothioconazole, fluopyram + prothioconazole, prothioconazole + benzovindiflupyr, prothioconazole + pydiflumetofen and folpet.
Disease pressure was significantly greater at the Kemptown location.
At both locations prothioconazole + benzovindiflupyr recorded up to 17% greater leaf number than all other treatments, and at least 48.6% less diseased leaves per stem than the untreated.
Mean NDVI for prothioconazole with benzovindiflupyr treatment plots was 13.8 and 62% greater than the untreated at the Kemptown and Debert locations, respectively.
This study demonstrates that the tank mix of prothioconazole with benzovindiflupyr offers the greatest control of foliar diseases in wild blueberries.
Authors
A. Cornel, D. Percival
Keywords
Vaccinium angustifolium, foliar fungicides, wild blueberries, Thekopsora minima, Sphaerulina vaccinii, Valdensia heterodoxa
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