The 2011 ASHS Annual Conference

Florida is the second largest strawberry growing region in the US with Hillsborough County having 90% of the state acreage.  Strawberries are planted in the fall and production goes through the winter into early spring.  Florida’s climate is sub-tropical and very humid.  Winter cold fronts typically bring rain to the area ahead of the front. Due to the very humid conditions, strawberry yield can be severely affected by two major fruit diseases, anthracnose fruit rot (AFR) and Botrytis fruit rot (BFR).  In certain years, growers have had severe economic losses due to these two diseases.  Fungicides are by far the most frequently applied pesticide and are applied on a frequent preventative schedule.  Consequently, fungicide applications account for nearly 15% of total production costs.  Researchers have been working for the last 3 years on a disease forecast system to advise growers on the timing of their fungicide applications.  Temperature and leaf wetness were used in the modeling system.  The goal of the disease management system is to develop and implement precision disease management that will reduce the total number of fungicide applications while maintaining excellent disease control and manage emerging or existing fungicide resistance. Reducing pesticide input and selecting reduced-risk fungicides over captan and thiram will reduce environmental impact, risks to pesticide applicators, and consumer exposure to pesticides.  To achieve this goal a web-based forecast system, the Strawberry Advisory System, for the timing of the fungicide sprays for these two diseases was developed and trialed by grower cooperators.  Growers received a text message and/ or e-mail message each time there was a risk for either disease and the level of risk would be stated in the message.  Grower cooperators were asked to spray designated blocks in their field only when there was a notice of risk of disease from the Advisory System.  Yields, from blocks of plants that were sprayed according to the disease forecast system and those sprayed by the grower’s regular preventative method, were taken for the 2009-10 and 2010-11 seasons.   By using the Strawberry Advisory System, growers were able to save money by cutting down the number of fungicide sprays they applied while still able to produce  a comparable number of marketable fruit.