Agribusiness Department

Degree Name

BS in Wine and Viticulture




James Ahern


This study was undertaken to see if using a powdery mildew prediction model combined with a JMS-Stylet oil based fungicide will incur less cost in preventing powdery mildew than a UC Davis standard recommendation sulfur based program.

To perform analysis, powdery mildew threat was predicted for Edna Valley using a temperature-triggering model, the Powdery Mildew Index. Two spray schedules were developed according the PMI and UC recommendations. Costs have compared for the two schedules using a partial budget.

It has been concluded that using the PMI to predict PM threat while using JMS-Stylet oil will incur less cost than the UC Davis standard recommendation program. This conclusion is based on the partial budget analysis that shows the posited recommendation cost to be 13% less than the UC Davis recommendation.