Assessing the United States Grape Industry’s Understanding of Fungicide Resistance Mitigation Practices

Abstract

In 2019, a national survey of 252 members of the USA grape industry from 20 USA states assessed knowledge perception of fungicide resistance management, application of that knowledge to vineyard practices, and knowledge acquisition sources. Overall, respondents demonstrated clear understanding of resistance management practices. The specific distribution of responses was influenced by the respondent’s job role, duration of industry experience, and their farming operation size. Nationally, respondents were moderately familiar with the acronym FRAC (Fungicide Resistance Action Committee), with nearly 75% indicating they could identify the FRAC code of a fungicide. They felt moderately competent they could design a fungicide program that adhered to resistance management principles. Respondents identified fungicide resistance as a serious problem nationally, and as a moderate problem in their own vineyards. They ranked practices that include rotating fungicides of different FRAC codes, avoiding multiple sequential applications of the same trade name or FRAC code, tank mixing with different FRAC codes, using multisite products in a spray program, routine sprayer maintenance and calibration, and good canopy management as very to extremely important in managing fungicide resistance; whereas practices such as rotating between trade names and tank mixing different trade names ranked slightly important. Respondents identified university-based Extension programs as the primary information resource for fungicide efficacy and fungicide stewardship (resistance management). In order to maximize potential impact, these results suggest that future educational efforts should be aimed at improving practices for fungicide resistance stewardship and should align with the knowledge base and demographic factors of the target audience particularly their job role, experience and size of operation.