Evaluation of Switch and Its Components (Scholar and Vanguard), with or without Abound, for Cranberry Fruit Rot Management in Massachusetts, 2024

Cranberry fruit rot (CFR), associated with a complex of over a dozen fungi including Coleophoma empetri, Allantophomopsis cytisporea, Botryosphaeria vaccinii, and Colletotrichum spp., which are among the most prevalent across major growing regions, is a major disease affecting cranberry ( Vaccinium macrocarpon Ait.) production in Massachusetts. Symptoms typically appear as soft, discolored, and rotten berries at harvest. This study evaluated the efficacy of the novel Syngenta fungicide Switch (cyprodinil + fludioxonil) and its individual components—Scholar (fludioxonil) and Vanguard (cyprodinil)—applied alone or in combination with Abound (azoxystrobin) for CFR management. A field trial was conducted in 2024 at the University of Massachusetts–Amherst Cranberry Station in East Wareham on cranberry cultivar ‘Stevens’, which is widely planted in Massachusetts and is often considered more susceptible to fruit rot than native cultivars (Early Black and Howes). Results showed that several treatments—particularly Scholar applied alone or with Abound and Vanguard and Switch when combined with Abound—significantly reduced CFR incidence and improved yield compared with the nonsprayed control, supporting their potential integration into CFR management programs.