Poster Session: Integrated Pest Management

314-P

Multi-year evaluation of standard- and model-timed fungicide applications for the control of Botrytis and anthracnose in commercial strawberry fields.
N. A. PERES (1), A. Amiri (2)
(1) University of Florida, Wimauma, FL, U.S.A.; (2) University of Florida, GCREC, Wimauma, FL, U.S.A.

Botrytis (BFR) and anthracnose (AFR) fruit rots, caused by Botrytis cinerea and Colletotrichum acutatum, respectively, are the two major diseases of strawberry. In this study, we report on the efficacy of model-timed fungicide applications compared to standard weekly applications in five commercial strawberry fields in Florida between 2010 and 2013. Fungicide applications based on models developed and tested previously were recommended only when the predicted proportion of flowers or fruits infected was ≥15% and ≥50% for AFR and BFR, respectively. Fruit were harvested weekly from December to March each year and BFR and AFR incidences and yield were estimated. The use of the predictive models reduced the number of sprays by 39 to 55%, 30 to 59%, and 30 to 50% in 2010-11, 2011-12, and 2012-13, respectively. Differences in BFR and AFR incidences were not significant between the two spray programs within the same field either in 2010-11 or in 2011-12. Preliminary data in 2012-13 confirmed results observed in the previous years for AFR whereas BFR incidence was significantly higher for the predictive model in two fields where a highly susceptible cultivar was grown. Overall, the model-timed fungicide applications did not have lower yields than standard weekly applications within the same field. These results show the value of using predictive models on reducing fungicide input without decreasing control.