Presidio fungicide available to Michigan hop growers

Section 18 Emergency Exemption for the use of Presidio fungicide for controlling downy mildew on Michigan hops has been approved.

The Michigan Department of Agriculture and Rural Development (MDARD) has approved a Section 18 Emergency Exemption for the use of the fungicide Presidio in Michigan hopyards due to unprecedented downy mildew infection resulting from the extremely wet weather in 2015. Presidio cannot be used on hops intended for the export market. Growers must have the Section 18 Exemption in hand; download the Section 18 Exemption label or request it from your pesticide distributor or from MDARD.

The severity of downy mildew in 2015 was caused by high disease pressure from previous downy mildew outbreaks, environmental conditions favorable for downy mildew, fungicide wash-off from frequent rain showers and cultivar susceptibility. Systemic infections have carried over into 2016, making management a challenge.

Michigan growers may make up to three applications of Presidio 4SC at a 4-ounce-per-acre rate. The pre-harvest interval (PHI) on hop is 24 days. Presidio should be tank-mixed with another downy mildew product (e.g., Forum, Curzate, Revus or Ranman) and applied at 10-14 day intervals, not in consecutive applications. The current weather pattern across much of the state remains favorable for downy mildew development, so limiting disease will be a challenge. Read the label before applying any pesticide.

According to MDARD, Section 18 of FIFRA, the federal law that regulates pesticides, authorizes the Environmental Protection Agency (EPA) to exempt state agencies (MDARD) from federal registration requirements if it is determined that “emergency” conditions exist that require an exemption. An emergency condition is an urgent, non-routine situation that will result in dire consequences if the exemption is not granted. Section 18 exemptions primarily allow the use of a pesticide on a site for which it is not federally registered. Michigan State University Extension specialists inform MDARD when such an emergency situation exists. They then work with MDARD to prepare a Section 18 exemption application for submission to EPA. Section 18 exemptions are valid for a single growing season and are specific to the state that requested the exemption.

This research was funded in part by Project GREEEN Award GR15-021.

This material is based upon work supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, under Agreement No. 2015-09785. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.

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