Temperature Fungicide Degradation

Temperature plays a critical role in the development of plant disease.  One important aspect of plant disease influenced by temperature is fungicide persistence, yet this remains unclear and largely unstudied.  Disappearance of the fungicides chlorothalonil and iprodione at 10, 20, and 30°C was measured on turfgrass leaf blades over a 4- or 5-week period, respectively, in 2010 and in two trials in 2011.  Concentrations of both fungicides declined more rapidly at 20 and 30°C compared to 10°C, though the impact on iprodione disappearance was more pronounced.  These results suggest that temperature influences the disappearance of fungicides on and within turfgrass leaf blades.  A greater understanding of the influence of temperature on fungicide disappearance may aid in developing more precise, efficient fungicide use strategies.

University of Wisconsin-Madison