Specialty crop and minor-use pesticide prioritization update from IR-4 Food Use Workshop

Nicole Soldan<schroe65@msu.edu>, Michigan State University Department of Horticulture, and Mary Hausbeck, MSU Department of Plant, Soil and Microbial Sciences - October 09, 2023

The 2024 meeting in Milwaukee set research priorities for the 2025 field program. Projects prioritized address fruits, vegetables, nuts, field and oil crops, herbs, and other miscellaneous crops in the U.S. and Canada.

The IR-4 Project helps specialty crop growers gain access to pest management tools so they can produce healthy, abundant harvests. Specialty crops include fruits, vegetables, herbs, nuts and other food crops, as well as flowers, shrubs and landscape plants—all of which are vital to public wellbeing.

The crop protection industry focuses their efforts on major crops, leaving specialty crop growers with fewer tools to effectively manage pests. The IR-4 Project develops data necessary for the registration of safe and effective pest management solutions with the U.S. Environmental Protection Agency. IR-4 also supports the registration of specialty uses on major crops such as corn, soybeans, and cotton.

Since 1963, the IR-4 Project has been instrumental in delivering pest management solutions to specialty crop growers by developing research data to support new EPA tolerances and labeled product uses. IR-4’s food crop research cycle is unique in that it invites all stakeholders to the table through the annual Food Use Workshop; at this meeting, participants work together to hone a long list of requested projects down to a fundable number of projects.

At the 2024 Food Use Workshop, held September 10-12 in Milwaukee, research priorities for the 2025 field program were selected; projects prioritized address fruits, vegetables, nuts, field and oil crops, herbs, and other miscellaneous crops in the United States and Canada. Approximately 144 people attended the three-day meeting (103 in person and 41 virtually), including: specialty crop researchers, extension specialists, representatives of commodity and industry groups across the country, personnel from EPA, USDA, IR-4, the AAFC (Agriculture and Agri-Food Canada that conducts Canadian counterpart of minor use program), and PMRA (Pest Management Regulatory Agency, i.e., Canadian counterpart of U.S. EPA).

Representing Michigan’s fruit and vegetable interests, the workshop was attended by MSU’s Mary Hausbeck, Timothy Miles, Rufus Isaacs, Nicole Soldan, Celeste Wheeler and Amber DeVisser. Representing a Michigan growers’ group was Pete Nelson (Cherry Marketing Institute). Also representing the IR-4 North Central Region was Daniel Heider (WI), Allison Robinson (OH), Ramawater Yadav (OH), Ashley Leach (OH), Cesar Escalante (IN), Stephen Meyers (IN), Mark Bernards (MN), Brian Jenks (ND) and Mohammad Babadoost (IL). Representing North Central Region grower’s groups was Robert Kaldunski (Wisconsin Ginseng), and Michelle Starke (Covercress).

The prioritization process focused on the most critical pest management needs from all disciplines, for each commodity. Participants were provided with a list of 152 pesticides nominated as “A” priorities prior to the Food Use Workshop. As a group, participants ranked products based on availability and efficacy of alternative pest management tools (including ongoing projects for the same need and resistance management), damage potential of target pest(s), performance and crop safety of the chemical in managing the target pest(s), compatibility of the proposed chemical candidate with Integrated Pest Management, uses currently covered by Section 18 emergency exemptions and harmonization implications due to lack of international MRLs (Maximum Residue Limits).

Based on projected budget appropriations for IR-4 in 2024, only 37 “A” priority projects throughout the disciplines were selected by consensus. An “A” priority triggers IR-4 to begin the field residue program during the following season and complete it within 30 months. The timeline will be shortened when IR-4 joins the company’s petition submission schedule with the expectation that a complete data package be submitted to the EPA in 16-24 months.

In addition to the above projects that require pesticide residue analysis under Good Laboratory Practices, 9 “H+” (high priority plus) efficacy/crop safety projects have been selected, because potential registrants want to see efficacy data before IR-4 conducts full residue studies, or the registrant requires only efficacy data to expand their label to include a certain crop or pest.

The Integrated Solutions (IS) platform addresses more complex needs of specialty crop growers, including pesticide resistance, pest problems without solutions, gaps in organic management, and residue mitigation. At this year’s Food Use Workshop, 60 IS projects were nominated as “A” priorities and due to budgetary restrictions, this list had to be narrowed down to 6 projects.

By the end of this meeting, twenty-three projects important for Michigan and the North Central Region were selected (Tables 1, 2, and 3). IR-4 was able to fund an additional 8 “A” or “H+” priority projects, through either Priority Upgrade Proposal (PUP) or Regional Upgrade Proposal (RUP). Out of the 8 funded upgrades, 3 “A” priorities and 3 “H+” priorities can benefit the North Central Region (Table 4).

The following new candidate priority “A” and “H+” projects listed are preliminary until confirmed at the IR-4 National Research Planning meeting on Oct 21-23, 2024. A complete listing can be found on the 2024 IR-4 Food Use Workshop website.

Table 1. Priority "A" projects for Michigan fruits and vegetables.

Group	COMMODITY	CHEMICAL	Reasons for Need
01CD	SWEETPOTATO	LINURON	For control of annual grass and broadleaf weeds.
06-22E	BEAN (DRIED SHELLED)	LINURON	Weeds control including hairy nightshade, palmer amaranth, and other amaranth species.
06-22F	PEA (DRY)	BROMOXYNIL	Broadleaf weeds, especially kochia. Kochia has developed resistance to key herbicides used for preplant/preemergence burndown applications, including Express (Group 2), Roundup (Group 9), and Sharpen/Aim Group 14. The only effective burndown herbicide remaining is paraquat, which some growers prefer not to use.
08-10A	TOMATO	PYRIDATE	Broadleaf weeds, especially kochia. Kochia has developed resistance to key herbicides used for preplant/preemergence burndown applications, including Express (Group 2), Roundup (Group 9), and Sharpen/Aim Group 14. The only effective burndown herbicide remaining is paraquat, which some growers prefer not to use.
12-12A	CHERRY	QUINCLORAC	Control of weeds such as field bindweed, hedgebindweed, canada thistle, barnyardgrass, and crabgrass.
12-12A	CHERRY	FLUAZINAM	American brown rot and European brown rot. Cherry leaf spot and brown rots. A fungicide with a different mode of action would be greatly benefit growers and improve disease resistance management efforts.
12-12B	PEACH	QUINCLORAC	Control of weeds such as field bindweed, hedge bindweed, Canada thistle, barnyard grass, and crabgrass.
12-12C	PLUM	QUINCLORAC	Control of weeds such as field bindweed, hedge bindweed, Canada thistle, barnyard grass, and crabgrass.
13-07A	CANEBERRY	GLUFOSINATE	Annual, biennial and perennial broadleaf and grass weeds that escape winter weed control strategies; For year-long weed control program; Alternative to paraquat and Glyphosate; Needed for resistance management
13-07G	STRAWBERRY (GH TRANSPLANT)	CHLORFENAPYR	Control of spider mites for greenhouse plants grown for consumers.
13-07H	CRANBERRY	FLUAZINAM	For pathogens that create fruit rot disease complex.
15-22D	CORN (SWEET)	ISOCYCLOSERAM (ISM-555)	Seed corn maggot control; Replacement for Chlorpyriphos;
20A	CANOLA	BROMOXYNIL	Broadleaf weeds, especially kochia.
20B	SUNFLOWER	BROMOXYNIL	Broadleaf weeds, especially kochia.
25AB	BASIL	LINURON	For control of annual weeds.
25AB	MINT (GH TRANSPLANT)	AZOXYSTROBIN + BENZOVINDIFLUPYR	Powdery mildew control for plants grown in the greenhouse for sale to consumers.
25AB	BASIL (GH TRANSPLANT)	AZOXYSTROBIN + BENZOVINDIFLUPYR	Fusarium control for plants grown in the greenhouse for sale to consumers.
99	FIELD PENNYCRESS (OIL SEED)	PROTHIOCONAZOLE	This use is needed to protect grain and seed production by managing the inoculum of Sclerotina, Alternaria and Albugo Candida left behind in the crop residue.
99	HEMP	SPIROTETRAMAT+ PYRIPROXYFEN	To control rice root aphid in the root zone.

Table 2. High priority needs for efficacy/crop safety projects for Michigan fruits and vegetables.

Group	COMMODITY	CHEMICAL	Reasons for Need
09B	SQUASH	ETHALFLURALIN + CLOMAZONE	Control of morning glory, pigweed, nutsedge
13-07B	BLUEBERRY (HIGHBUSH)	EPYRIFENACIL	Annual grasses and broadleaf weeds, including bluegrass, horseweed, common lambs quarters, morning glory, Virginia pepperweed, common ragweed, annual bluegrass (diuron and glyphosate resistant), horseweed (glyphosate and paraquat resistant).

Table 3. Integrated Solution Projects for Michigan fruits and vegetables.

Group	COMMODITY	Title	Problem	Reasons for Need
09B	Summer squash	Squash bug	Organic	Organic solutions for control of squash bug in summer squash.
13-07B	Blueberry (Highbush)	Spotted Wing Drosophila	Resistance Manage-ment	The most challenging insect pests during harvest season for blueberries include spotted wing Drosophila. Biopesticides, sterilants, and berry cuticle enhancers are being used by growers, or have been evaluated with promising results. These approaches delay resistance development, improve pest control, and reduce residues.

Table 4. Priority Upgrades and Regional Upgrades for North Central Region fruits and vegetables.

Group	COMMODITY	CHEMICAL	Reasons for Need
12-12B	PEACH	TERBACIL	“A” Priority - Shorten the PHI to 30 days to permit weed control closer to harvest.
13-07G	STRAWBERRY (GH TRANSPLANT)	FLUTIANIL	“A” Priority – Powdery mildew control for plants grown in the greenhouse for sale to consumers.
25AB	MINT (GH TRANSPLANT)	FLUTIANIL	“A” Priority – Powdery mildew control for plants grown in the greenhouse for sale to consumers.
13-07F	GRAPE	FLUAZINAM	“H+” Priority – Expand label to include downy mildew.
08-10A	TOMATO	INPYRFLUXAM	“H+” Priority – Post plant application to control southern blight caused by athelia (sclerotium) rolfsii.
11-10	APPLE	EPYRIFENACIL	“H+” Priority - Alternative to paraquat, glufosinate, glyphosate, and carfentrazone annual broadleaves and grasses, and burndown of perennial weeds.

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