Fungicide Effectiveness on Established Cranberry Stands.

Fungicides are commonly applied to cranberry stands to prevent fruit rot, a complex disease caused by over fifteen different fungal species. If left untreated, fruit rot can cause crop loss in excess of 50%. A current trend in the industry that some growers are practicing is to discontinue fungicide application to cranberry stands seven years after planting when stands are considered established. However, there has been no prior research to support this practice. The objective of this study is to determine the effects of fungicide application on older established stands. This research will be conducted in Necedah, WI on a 7-year old ‘Mullica’ cranberry stand. In this study there will be two replications of the trial and two beds per trial. Each bed will be split in half and 4 scenarios will be tested per trial. Scenario 1 will test Proline® (prothioconazole) fungicide that will be sprayed at 10% bloom with a rate of 5 oz. /ac. Scenario 2 will test Indar® (fenbuconazole) fungicide at a rate of 12 oz. /ac. along with Abound® (azoxystrobin) fungicide at 12oz. / ac. that will be sprayed only at 50% bloom. Scenario 3 will test Proline® (prothioconazole) being applied at 10% bloom along with Indar® (fenbuconazole) and Abound®(azoxystrobin) being applied at 50% bloom, this is the standard practice for yearly fungicide use. Scenario 4 will be untreated. Percent fruit rot and yield will be measured by collecting eight, square foot plots in each of the treated areas at the end of the growing season to determine treatment efficacy. Data from this study will be used to inform future fungicide application practices in the cranberry industry.