EAST LANSING, Mich. — The IR-4 Project (Interregional Research Project No. 4) has been facilitating registration of sustainable pest management technology for specialty crops and minor uses. Since 1963, the IR-4 Project has been the major resource for supplying pest management tools for specialty crop growers by developing research data to support new EPA tolerances and labeled product uses. Specialty crop research needs are prioritized each year during a national workshop since resources are limited, according to IR-4.
Research priority A’s for the year 2020 field program for fruits, vegetables, nuts, field and oil crops, herbs and other miscellaneous crops in the United States and Canada were selected at the Food Use Workshop held Sept. 23-24, 2019, in Hunt Valley, Maryland. About 200 people attended the two day meeting: specialty crop researchers, extension specialists, representatives of commodity and industry groups across the country, and personnel from EPA, USDA, IR-4 plus 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).
For Michigan’s fruit and vegetable interest, the workshop was attended by Michigan State University’s Bernard Zandstra, Anthony VanWoerkom, John Wise, Mary Hausbeck, Debalina Saha, Marisol Quintanilla, Tim Miles and Lynnae Jess. Representing Michigan grower’s group was Dave Trinka (blueberry) and representing a large portion of Michigan greenhouses was Karin Tifft (Mastronardi Produce).
The prioritization process focused on the most critical pest management needs from all disciplines for each commodity. Participants were provided with a list of 245 pesticides “nominated” with desired priority of A prior to the food-use workshop. As a group they 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 2020, only 49 A priority projects throughout the disciplines were selected by consensus. One hundred sixty-nine projects were down-graded to B priority. An A priority guarantees 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 GLP, eight H+ (high priority plus) efficacy/crop safety projects will be selected, because potential registrants want to see the data first before IR-4 conducts full residue studies, or IR-4 needs to screen pest control products for new pests, the PPWS (pest problems without solution) projects.
Thirty-four priority projects important for Michigan were selected and three B priorities have already been upgraded to A priority status through the priority upgrade process (PUP). In addition, 14 candidate H+ projects for Michigan growers were identified (see Table 2). Any more B priority projects must be upgraded to A priority either by an Priority Upgrade Proposal (PUP) with good justification or by regional upgrade, i.e., the crops or the pests are limited to a particular region. At present, IR-4 may consider 10 upgrades should the budgetary situation become more favorable.
The following new candidate priority A and H+ projects listed are preliminary until affirmed at the IR-4 national research planning meeting on Oct. 29-Nov. 1, 2019. A complete listing can be found on the IR-4 website.
|Table 1. Priority A projects for Michigan fruits and vegetables|
|Group||Commodity||Chemical||Reasons for need|
|01AB||Beet (garden)||Flutolanil||Pocket rot, leaf spot, rhizoctonia solani; per WI me-too request, need additional fungicides for root rots of table beets: 07/19|
|01AB||Beet (garden)||Xde-659||Cercospora leaf spot; information about efficacy for phoma leaf spot would be useful; due to fungicide resistance, target disease is difficult to manage successfully with available fungicides and alternatives are needed to follow label use restrictions for resistance management; per RI me-too request, this is needed for cercospora which is pervasive on table beets in RI and is being seen earlier every year; per mi me-too request, this is an expanding crop in mi, and foliar diseases are more important|
|01AB||Beet (sugar)||Abamectin||Two spotted spider mite; need a second insecticide to rotate mode of action for spider mites; currently only have onager|
|01AB||Carrot||Flutolanil||Crater rot (rhizoctonia), southern blight (sclerotium rolfsii) – preventative|
|01AB||Carrot (upgraded to A)||XDE-659||Alternaria and cercospora; additional products are needed for alternation with bravo and the strobilurins|
|01AB||Ginseng||Xde-659||Alternaria panax; resistance has been noted to strobilurins; multiple products are needed to protect the crop over an extended growing period of may through september|
|01AB||Ginseng (upgraded to A)||2,4-D||Broadleaf weeds; currently no broadleaf herbicides labeled for use on ginseng during the growing season; currently, growers hand weed gardens (when and if crews are available to hire) at the cost of several thousands of dollars per acre per year|
|01AB||Radish (upgraded to A)||XDE-659||Alternaria and cercospora foliar blights|
|01CD||Sweet potato||Glufosinate||Annual broadleaf weeds|
|01CD||Sweet potato||Paraquat||Weeds; no postemergence herbicides registered for weed control in plant beds; per ca me-too request, a contact herbicide, rather than systemic like glyphosate, may have better crop safety at this time; potential comparison products may be suppress at 6%, rely, roundup:09/19|
|03-07AB||Onion||Xde-659||Botrytis and alternaria; fungicide is suspected weak on stemphylium but worthwhile to obtain observations on performance if this fungus also occurs; due to fungicide resistance, target pathogens are difficult to manage successfully with available fungicides and alternatives are needed to follow label use restrictions for resistance management|
|04-16A||Lettuce (greenhouse)||Xde-659||Botrytis, powdery mildew, early blight, septoria, alternaria, sclerotinia, fusarium (suppresion); per IL and NY me-too requests, need to have an alternative for botrytis management when organic products are not enough|
|04-16B||Greens (mustard)||S-metolachlor/metolachlor||Galinsoga, purslane, annual grasses, yellow nutsedge; current 30-day phi is too long for current market conditions, often delaying harvest beyond optimum maturity; per FL me-too request, a shorter phi is needed due to growing demand for younger, more tender greens; per ca me-too request, there are horrible weed problems in their mustard fields|
|05-16||Broccoli||Xde-659||Alternaria leaf spot; due to fungicide resistance, target disease is difficult to manage successfully with available fungicides and alternatives are needed to follow label use restrictions for resistance management; per RI me-too request, alternaria is a very significant broccoli disease, with increasing pressure due to growing of other susceptible brassica crops alongside broccoli; per mi me-too request, broccoli is a niche crop in mi and is grown later in the fall for processing, when the dew periods are extended and disease is more likely|
|06C||Bean (dried shelled)||Cyazofamid||Pythium aphanidermatum, cottony leak|
|06C||Pea (dry)||Bentazon + acifluorfen||Broadleaf weeds; unique mode of action; post plant applic; this dual ai product provides better crop safety; potential 60-80,00 acres in id, and weed control problems are similar to WA; per mt me-too request, dry peas are a major crop in mt, and this need has industry support|
|08-10A||Tomato (greenhouse)||Xde-659||Botrytis, powdery mildew, early blight, septoria, alternaria, sclerotinia, fusarium (suppresion); per co, me, oh and mi me-too requests, botrytis is a big problem in tomatoes; per NY me-too request, pesticide also needed for powdery mildew, leaf mold and sclerotinia timber rot; all 4 diseases are major problems in high tunnels in the northeast; per KY me-too request, botrytis and leaf mold are critical greenhouse problems, and only greenhouse-labeled chemicals may be used in high tunnels in KY; so, the need for new modes of action is dire; per mi me-too request, this use is important for tomato production, and for transplants destined for the retail market|
|08-10A||Tomato (processing)||Sulfosulfuron||Branched broomrape (orobanche ramosa); orobanche is an emerging invasive pest to California; management and control programs in other countries have evaluated many control options and come to the conclusion that sulfosulfuron is an effective tool for this pest; in the case that long term management is needed, a review and quicker access to this tool will be crucial|
|08-10B||Pepper (bell)||Flutolanil||Southern blight (sclerotium rolfsii)|
|08-10BC||Pepper (greenhouse)||Xde-659||Botrytis, powdery mildew, early blight, septoria, alternaria, sclerotinia, fusarium (suppresion); per oh, co, me and mi me-too requests, botrytis causes significant losses|
|09||Cucurbit vegetables (transplants) (greenhouse)||Uniconazole-p||Control stem elongation by blocking GA synthesis producing more compact plants; per GA and CA 06/19 me-too requests: need sumagic to control stretch on all cucurbit transplants (grafted and non-grafted)|
|09B||Cucumber (greenhouse)||Xde-659||Gummy stem blight (GSB), botrytis, powdery mildew, early blight, septoria, alternaria, sclerotinia, fusarium (suppresion); per OH and MI me-too requests, GSB causes crop loss|
|12-12C||Plum||Kasugamycin||Bacterial blast and canker; copper resistance is widespread in the pathogen population|
|13-07B||Blueberry||Pyrifluquinazon||Chilli thrips, citrus thrips; only few labeled products are effective; per CA me-too request, is a high priority in CA against citrus thrips, not chilli thrips, in blueberry; few products are available, and there is documented resistance of citrus thrips to pyrethroids and spinosyns; is highly effective|
|13-07B||Blueberry||Xde-659||Mummy berry, botrytis blossom blight and fruit rot, and anthracnose fruit rot; we lack several modes of action to control blueberry anthracnose|
|13-07F||Grape||Fluazinam||Ripe rot (caused by colletotrichum spp.); has been an increasing disease in vineyards in the mid-Atlantic region; control of ripe rot typically relies on strobilurins, but resistance in colletotrichum has been found widespread; captan probably is one of the few fungicides that has proven to be effective against the disease in addition to qois; unfortunately it is not favored closer to harvest from wine perspective; therefore, the fungicide choices for ripe rot management are very limited; fluazinam is labeled on blueberries for anthracnose (same pathogen that causes ripe rot on grapes) control, and it also showed good efficacy (similar to captan) for control of strawberry anthracnose fruit rot|
|13-07G||Strawberry (greenhouse)||Xde-659||Botrytis, powdery mildew, early blight, septoria, alternaria, sclerotinia, fusarium (suppresion); per OH and MI me-too requests, botrytis is a big problem in greenhouse strawberries|
|19A||Basil||Acifluorfen||Annual broadleaves and grasses; the result should be better quality fresh product, and larger yields; few safe and effective herbicides are labeled for basil; per IL me-too request, need purslane control, for which other herbicides are not as effective; per HI me-too request, basil growers there need an effective herbicide for round-up resistant weeds and for post emergence use since the growing season is year round; per CA me-too request, they struggle with a variety of horrible weed problems and currently available herbicide options do very little, if anything at all: 08/19|
|19A||Herbs (greenhouse)||Xde-659||Botrytis; there are few fungicides registered for use on herb transplants for retail sale|
|99||Hemp, industrial||Bromoxynil||Broadleaf weeds; no postemergence herbicides are labeled in hemp; per mt me-too request, weed control is the primary issue in hemp in MT, and growers need tools for dicot weeds|
|99||Hemp, industrial (field & greenhouse)||Azoxystrobin||Fungal leaf spots, mainly cercospora and septoria, pythium, botrytis, s. Rolfsii, fusarium, powdery mildew, downy mildew; there are currently no effective conventional products labeled for disease control in hemp; per KY me-too request, fungal leaf spots, root rots and other diseases are severe in hemp in KY: 09/19|
|99||Hops||Xde-659||Hop powdery mildew; there’s a critical need for an additional powdery mildew fungicide, due to the impending loss of the MRL for quinoxyfen in the EU market due to the cut-off criteria|
|99||Mint||Fluazaindolizine||Nematodes (root knot, root lesion, pin); the U.S. mint crop only has two products registered for nematode control, and both are under registration scrutiny; mint needs more options available|
— Anthony VanWoerkom, John Wise and Bernard Zandstra, Michigan State University Extension
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