Effects of in-season crop-protection combined with postharvest applied fungicide on suppression of potato storage diseases caused by oomycete pathogens

The effects of fungicides and biofungicides applied during the growing season in combination with storage applications to control potato storage diseases caused by oomycete pathogens were evaluated. The in-season treatments included in-furrow and foliar application of mefenoxam or phosphorous acid and foliar application of Bacillus subtilis. Storage treatments included phosphorous acid, B. subtilis and a 3-way mixture of azoxystrobin, fludioxonil and difenoconazole. These products were tested for control of tuber late blight, Pythium leak and pink rot at 10 °C (cv. FL1879) or 4 °C (cv. Goldrush). The combination of phosphorous acid in the field and during storage significantly reduced tuber blight development. Field treatment with B. subtilis, mefenoxam or phosphorous acid combined with the storage treatment of phosphorous acid significantly reduced Pythium leak development. Interaction of field treatments, mefenoxam or phosphorous acid, with storage treatments, phosphorous acid or the 3-way mixture of azoxystrobin, fludioxonil and difenoconazole significantly reduced pink rot incidence.

► Storage oomycete potato diseases controlled by in-season and postharvest strategy.
► Phosphorous acid applied in the field and postharvest reduced tuber blight.
► 3-way mixture of azoxystrobin, fludioxonil and difenoconazole reduced pink rot.
► Use of these products should be integrated with other management strategies.