Rutgers University | New Jersey Agricultural Experiment Station | Pesticide User Responsibility

June 29, 2021

About the safe use of glufosinate and glyphosate herbicides in apple and peach orchards

Recently, New Jersey tree fruit growers have expressed concerns regarding the use of glufosinate for weed control in apple and peach orchards.

Glufosinate is a nonselective post-emergence foliar herbicide that can be used for directed applications around trees, vines, and berries. Glufosinate provides control of many annual broadleaf and grass weeds; however, control of large or well-tillered annual grasses, such as yellow or giant foxtail  can be marginal. Glufosinate has no soil activity.

Work conducted by Dr. Brad Majek a few years ago indicated that direct application of glufosinate to the mature brown bark of the lower trunk may cause severe injury by killing the cambium layer at the point of contact (https://plant-pest-advisory.rutgers.edu/glufosinate-products-sold-as-rely-280-expand-as-generic-products-enter-the-market/). However, this type of injury is not systematically associated with glufosinate application as we observed it in a trial conducted in 2017 at the Snyder Research Farm on mature “Pink Lady” apple trees which were not damaged following glufosinate application  (Rely 280 at 64 fl oz/A). Additionally, injury in the form of vertical cracks in the of trunk bark have also be observed on apple trees exposed to glyphosate (https://nyshs.org/wp-content/uploads/2016/10/Pages-23-28-from-NYFQ-Winter-12-12-2013.cmc_.pdf), not only to glufosinate.

As highlighted by Dr. Dave Rosenberg (retired Plant Pathologist at Cornell’s Hudson Valley Lab) on his blog (https://blogs.cornell.edu/plantpathhvl/2014/06/30/apple-summer-diseases-herbicide-problems-and-irrigation/), “NEITHER glyphosate nor glufosinate cause trunk injury to apple trees EVERY time that they are used or in every orchard in which they are applied”. Field reports suggest that injury is detected when trees are exposed to specific conditions that still need to be precisely defined. Dr. Rosenberg’s opinion is that “the potential for damage is significantly higher if tree trunks are hit with either of these herbicides during or just prior to periods of drought stress”. Under these drought conditions, “the additional desiccation from herbicide exposure may predispose the trunks to invasion by Botryosphaeria dothidea, a canker pathogen that is incapable of killing the cambium in healthy functioning trees, but which becomes very pathogenic in drought-stressed trees”. Dr. Rosenberg also suspects that similar injury can be observed on young trees following application of paraquat. Other stress factors, such as cold injury or previous bark damages, may also increase the risk of herbicide injury.

So, to safely apply glyphosate or glufosinate in peaches or apples, it is important following some guidelines that will help minimizing glyphosate or glufosinate damages to the bark:

  • As specified by the label for glufosinate products and the Rutgers 2021-22 E002 Rutgers Tree Fruit guide, contact by the herbicide of parts of trees other than mature brown bark (including suckers) can result in serious damage. It is therefore especially important to protect young trees from potential glufosinate or glyphosate injury by wrapping them with grow tubes or waxed containers.
  • For mature trees, the use of a shield boom is required for minimizing as much as possible contact between the herbicide spray and the tree bark. Shields will also minimize the bounce-back from bare soil that sometimes allows a haze of small droplets to drift upward into the trees.
  • Avoid applications of herbicides during periods when trees are already experiencing water stress or where water-stress can be expected in the near future. Additionally, weed control efficacy of herbicides such as glyphosate of glufosinate can severely decrease when weeds are under heat stress.
  • Keep the pressure as low as possible (no more than 30 psi) to minimize generation of small droplets. If not feasible, use air-induction nozzles to reduce the production of small droplets.
  • Glyphosate should not be applied immediately after suckers are cut because it is readily absorbed by freshly cut stems.
Filed Under: Fruit, Tree Fruit, Wine Grape Tagged With: , , ,
May 25, 2021

Stinger herbicide 24(c) Special Local Need label renewed until 2025 for use on Highbush Blueberries

Blueberry bushes

Mugwort in blueberries is also called wild chrysanthemum due to its scent when the leaves are crushed.

The NJDEP informed us last Friday that the 24(c) Special Local Need label for use of Stinger (clopyralid) herbicide in highbush blueberries has been renewed for the 5 years with an expiration date set on December 31, 2025.

This is a really good news for the New Jersey Blueberry Industry as Stinger is a crucial herbicide for control of troublesome perennial weed species that has consistently showed excellent crop safety when used accordingly to the label recommendations. The new updated 24(c) label can be found on the Agrian database (https://www.agrian.com/labelcenter/results.cfm)

Stinger is a PRE and POST herbicide that is strong on weeds in the composite and legume families, such as thistles, asters, dandelion, goldenrod, ragweed, horseweed, clovers, vetch and wild bean. It also controls nightshades, smartweeds, wild buckwheat and plantain.

The maximum labeled rate of Stinger per application 5.3 fluid ounces per acre (0.125 lb acid equivalent/A), and the maximum rate per year application is 10.6 fluid ounces per acre (0.25 lb acid equivalent/A). However, the rate needed varies depending on the target species:

  • 2 fl ounces per acre (0.047 lb acid equivalent/A) will control seedling annual weeds such as common ragweed and annual vetch.
  • 3 to 4 fluid ounces per acre (0.070 to 0.094 lb acid equivalent/A) are needed to control perennial clover species, horseweed, and groundsel.
  • Most other susceptible perennial weeds require the full rate of 5.3 fluid ounces per acre (0.125 lb acid equivalent/A).

Optimum results controlling deep rooted and hard to control perennial weeds, including Canada thistle, perennial asters, goldenrod species, and mugwort (wild chrysanthemum) will be obtained if the Stinger application is split.

Apply Stinger at the rate of 5.3 fluid ounces per acre after blueberry bloom in early to mid-May when the weed is emerging. Some weeds can “survive” for months on established existing foliage even though Stinger suppresses all new growth. Tank-mix with another postemergence herbicide to increase the spectrum of weeds controlled. Be sure to spray adjacent sod and tilled row middles as well as the weed free strip under the blueberries. The application of Stinger timed to match the emergence of the perennial weed in the spring coincides with the time of year when the carbohydrate food reserves in the plant are at the lowest point. Treatment at this time reduces the weed’s chance of recovery and survival.

Apply another 5.3 fluid ounces per acre of Stinger to the marked rows, or sections of rows immediately after harvest in mid-summer. No growth of the target weed may be observed at the time of the second application. Spray the second application even though no growth of the target weed is evident. The second application is essential for the elimination of the hard to kill established perennial weeds. If the second application is skipped, expect to see the weed re-emerge in late August or September. Time all applications to maintain a 30 day PHI (PreHarvest Interval).

Stinger is both a postemergence foliar absorbed herbicide and a residual herbicide. The initial twisting and curling observed after application to susceptible species is due to the foliar absorbtion. Control of established perennials is due to residual Stinger in the soil which prevents re-growth from the roots. In certain species such as mugwort, Stinger prevents re-growth but does not kill the mature leaves. The plant will survive unless another herbicide such as Gramoxone or glyphosate is used to defoliate the plant.

Deep rooted perennials

Deep rooted perennials like goldenrod will require multiple Stinger applications.

Stinger can also be used as a wipe treatments by applying a 2% solution of Stinger in water (2.5 fluid ounces per gallon). Make a maximum of two applications with the total usage of Stinger from all types of applications not to exceed 10.6 fl oz per acre or 2/3 pint (0.25 lb acid equivalent/A) per acre per annual growing season.

Do NOT apply Stinger in a hand held sprayer used to “spray until wet”. Stinger is a residual herbicide that must be applied on a rate per acre basis. When treating “patches” of perennial weeds, apply the recommended rate per acre with a calibrated sprayer. Treat ten to fifteen feet beyond the weed “patch” on all sides. Spray the sod or row middles adjacent to the weed “patch” in the row.

Do NOT apply Stinger within 5 hours of expected rainfall or irrigation.

Do NOT permit Stinger to contact desirable foliage

 

 

 

Filed Under: Blueberry, Fruit Tagged With: , ,
March 5, 2021

2021 Recommendations for Residual Weed Control in Established Blueberry

Horseweed

Horseweed / Marestail

With T3 stage scheduled for early April  it’s now time  to consider your residual herbicide application before bud-break!

Residual herbicides should be applied prior to weed seed germination. If applied to weeds that are already out of the ground, most of these products will not control them.

Keep also in mind that these herbicides should receive at least ½” rainfall or irrigation one to seven days after application (depending on herbicides) to move the herbicide into the soil

 

 

In order to reduce the potential of selecting for herbicide-resistant weeds, it is highly recommended mixing two residual herbicides with different MOA whenever you apply pre-emergence (residual) herbicides. Make sure the herbicides you plan to apply will be effective at controlling the weed species in your field by checking the herbicide label. Usually, residual herbicides will suppress weed for 6 to 8 weeks depending on irrigation as well as soil and weather conditions. After this period, another residual herbicide can be needed to control weeds through harvest and could be mixed with a postemergence herbicides to control emerged weeds. Roundup (glyphosate), Rely 280 (glufosinate,) and Gramoxone (paraquat) are postemergence herbicides that may be applied with pre-emergence herbicides before bud break with little risk for crop injury.

  •  MOA 2: Solida (rimsulfuron) and Sandea (halosulfuron) are ALS inhibitors that have both preemergence and postemergence activity. They control most annual broadleaves but are weak on common groundsel, common lambsquarters and eastern black nightshade. Sandea is ONLY recommended for postemergence control of yellow nutsedge. However, these two herbicides will not control ALS resistant weeds (horseweed, ragweed…) already widespread in New Jersey. Thus, these herbicides should always be tank mixed with a partner effective at controlling these weeds
  • MOA 3: Kerb (pronamide) and Surflan (oryzalin) are mitosis inhibitor that will be effective at controlling many annual grass species for 4 to 6 weeks after application. Kerb also help controlling perennial quackgrass. If applied to warm soils (> 55°F), Kerb persistence (and weed control) is much reduced; therefore, reserve Kerb for fall/winter application. Do not use Kerb on blueberries that have not been established for about a year.
  • MOA 5 and 7: The photosynthesis inhibitors (PS II inhibitors) have a broad spectrum of control and will be effective against many broadleaves and annual grasses when applied in spring. Karmex (diuron) and Princep (simazine) have relatively low solubility and have been very safe on blueberries. Sinbar (terbacil) has a longer residual life in the soil and also is more soluble, so it should be used infrequently on light, wet soils. Velpar (hexazinone) is very soluble and should not be used on New Jersey sandy soils. These herbicides are effective on a many broadleaf weed species, including common chickweed, common lambsquarters, common groundsel, henbit, nightshade, redroot pigweed, pineappleweed, shepherd’s-purse, smartweed, and some mustards. Sinbar and Princep will also control most of the annual grasses and help suppressing quackgrass.
  • MOA 12: Solicam (norflurazon) is a pigment inhibitor that may be applied in fall or early spring primarily for annual grass control and quackgrass suppression. Solicam may also provide partial control of many broadleaf weeds as well as of yellow nutsedge. Do not use Solicam on blueberries that have not been established for about a year.
  • MOA 14: Chateau (flumioxazin), Zeus XC (sulfentrazone), and Zeus Prime XC (sulfentrazone plus carfentrazone) are PPO inhibitors with activity against many broadleaves (including redroot pigweed, catchweed bedstraw, common mallow, common lambsquarters, ladysthumb, wild mustard, and shepherd’s-purse) when applied preemergence in spring. Chateau and Zeus Prime XC also have some postemergence activity on newly emerged seedlings of annual weeds. Zeus products may also provide some suppression of yellow nutsedge. Chateau has a 7 day preharvest interval (PHI) and Zeus Prime XC have 3 day PHI, and can therefore be applied later in the season to extend preemergence broadleaves control into late summer. Blueberry plants must have been established at least two years prior to use of these herbicides.
  • MOA 15: Devrinol (napropamide) and Dual Magnum (s-metolachlor) are long chain fatty acid inhibitor. Devrinol will provide good control of annual grasses and should therefore be tank mixed with a PSII or a PPO inhibitor for controlling broadleaf weeds. Devrinol is rapidly degraded if left exposed on the soil surface, so it should be applied less than 24 hours before a rain event to incorporate the herbicide in the soil. Dual Magnum has a 24c Special Local Need label for blueberry in New Jersey. This herbicide controls many annual grasses and some small-seeded broadleaf annual weeds such as redroot pigweed, nightshade and common purslane. Dual Magnum also suppresses emergence of yellow nutsedge. Use Dual Magnum only on plants established for more than one year, and lower rates are suggested on 2- to 3-year-old plantings.
  • MOA 20: Casoron (dichlobenil) is a cellulose synthesis inhibitor recommended for fall application to control many annual and perennial broadleaves, grasses and yellow nutsedge. If left on the soil surface or if applied to warm soil (> 55°F or 70°F depending on dichlobenil formulation), Casoron can lose much of its activity. So, reserve this herbicide ONLY for fall/winter applications. Plants must be at least one year old before Casoron should be used.
  • MOA 21: Trellis SC (isoxaben) is a cell wall synthesis inhibitor currently currently registered for bearing and non-bearing blueberry. Trellis SC primarily controls annual broadleaf weeds, such as horseweed, common lambsquarters, wild mustards, shepherd’s- purse, purslane, and common chickweed; higher rates may also suppress field bindweed and curly dock. However, Trellis SC will have to be mixed with a Group 3, 12, or 15 residual herbicide for controlling annual grasses.
  • MOA 27: Callisto (mesotrione) is an HPPD inhibitor recommended for spring application to control many annual broadleaf weeds as well as annual sedges. It controls large crabgrass but no other grasses, such as goosegrass. Callisto may be used as a broadcast spray between rows to control broadleaves and crabgrass without injuring the fescue sod. Callisto has both preemergence and postemergence activity and can be used in spring prior to bloom to control ALS-resistant horseweed at the rosette stage.
  • MOA 29: Alion (indaziflam) is a cellulose biosynthesis inhibitor recommended for fall or spring application to control annual broadleaf and grassy weeds. Alion has no effect on emerged weeds or established perennials. It should be applied before weeds emerge or tank-mixed with a postemergence (POST) herbicide to control emerged weeds. Do not use Alion on soil classed as sand, or with more than 20% gravel.

Soil-Applied Herbicide Rates (in Active Ingredients) for Common Soil Types

Graph of Soil-Applied Herbicide Rates

N/A = NOT LABELED (DO NOT USE).
1Use the lower recommended rate when tank-mixing with another pre-emergence herbicide, unless annual grass pressure is severe.
2Use one-half the recommended rate when tank-mixing with another pre-emergence herbicide.

The 2021 Commercial Blueberry Pest Control Recommendations for New Jersey will soon be available on https://njaes.rutgers.edu for rates and additional information. The information above is correct to the best of our knowledge. Other formulations with the same active ingredient as some of the products listed above may exist that may or not may be labeled for the same uses. Always consult the label before making pesticide applications. Information was current as of March 5, 2021

Filed Under: Blueberry, Uncategorized Tagged With: , ,
October 28, 2020

EPA Announces 2020 Dicamba Registration Decision

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Today, U.S. Environmental Protection Agency (EPA) Administrator Andrew Wheeler announced that EPA is approving new five-year registrations for two dicamba products and extending the registration of an additional dicamba product. All three registrations include new control measures to ensure these products can be used effectively while protecting the environment, including non-target plants, animals, and other crops not tolerant to dicamba.

“With today’s decision, farmers now have the certainty they need to make plans for their 2021 growing season,” said EPA Administrator Andrew Wheeler. “After reviewing substantial amounts of new information, conducting scientific assessments based on the best available science, and carefully considering input from stakeholders we have reached a resolution that is good for our farmers and our environment.”

Through today’s action, EPA approved new registrations for two “over-the-top” (OTT) dicamba products—XtendiMax with VaporGrip Technology and Engenia Herbicide—and extended the registration for an additional OTT dicamba product, Tavium Plus VaporGrip Technology. These registrations are only for use on dicamba-tolerant (DT) cotton and soybeans and will expire in 2025, providing certainty to American agriculture for the upcoming growing season and beyond.

To manage off-site movement of dicamba, EPA’s 2020 registration features important control measures, including:

  • Requiring an approved pH-buffering agent (also called a Volatility Reduction Agent or VRA) be tank mixed with OTT dicamba products prior to all applications to control volatility.
  • Requiring a downwind buffer of 240 feet and 310 feet in areas where listed species are located.
  • Prohibiting OTT application of dicamba on soybeans after June 30 and cotton after July 30.
  • Simplifying the label and use directions so that growers can more easily determine when and how to properly apply dicamba.

The 2020 registration labels also provide new flexibilities for growers and states. For example, there are opportunities for growers to reduce the downwind spray buffer for soybeans through use of certain approved hooded sprayers as an alternative control method. EPA also recognizes and supports the important authority FIFRA section 24 gives the states for issuing locally appropriate regulations for pesticide use. If a state wishes to expand the federal OTT uses of dicamba to better meet special local needs, the agency will work with them to support their goals.

This action was informed by input from state regulators, grower groups, academic researchers, pesticide manufacturers, and others. EPA reviewed substantial amounts of new information and conducted assessments based on the best available science, including making Effect Determinations under the Endangered Species Act (ESA). With this information and input, EPA has concluded that these registration actions meet Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) registration standards. EPA believes that these new analyses address the concerns expressed in regard to EPA’s 2018 dicamba registrations in the June 2020 U.S. Court of Appeals for the Ninth Circuit. Further, EPA concluded that with the control measures now required on labels, these actions either do not affect or are not likely to adversely affect endangered or threatened species.

To view the final registration of the dicamba products, visit docket EPA-HQ-OPP-2020-0492 at www.regulations.gov.

Background

The United States is the world’s leading soybean producer and second-leading soybean exporter and also serves as the world’s third-largest cotton producer and the leading cotton exporter. Today, there are limited cost-effective options to control herbicide-resistant weeds affecting these commodities. In 2018, approximately 41 percent of U.S. soybean acreage was planted with dicamba-tolerant (DT) seed and almost 70 percent of U.S. cotton acreage was planted with DT seed in 2019. Relative to alternative herbicide programs, postemergence dicamba may reduce weed control costs for some growers, possibly by as much as $10 per acre, or over five percent of net operating revenue, not accounting for all measures growers will have to take to control off-field movement of dicamba.

Following reports of damage resulting from the off-site movement of dicamba, EPA amended the dicamba registration labels in 2017 and in 2018. In June 2020, the U.S. Court of Appeals for the Ninth Circuit vacated the registrations for three dicamba products: XtendiMax with VaporGrip Technology, Engenia Herbicide, and DuPont FeXapan Herbicide. As a result of the Court’s decision, EPA issued cancellation orders outlining limited circumstances under which existing stocks of the three affected products could be distributed and used until July 31, 2020.

 

Filed Under: Commercial Ag Updates, Field, Forage & Livestock, Fruit, Landscape, Nursery, & Turf, Vegetable Crops Tagged With: , ,
September 2, 2020

Reflex 2SL received a 24(c) SLN label for transplanted peppers and tomatoes

Regulation

A 24(c) Special Local Needs label has been recently approved for New Jersey for use of Reflex herbicide for Control of Weeds in Transplanted Tomatoes and Transplanted Peppers. The use of Reflex 2SL is legal ONLY if a waiver of liability has been completed on the Syngenta website (https://www.syngenta-us.com/labels/indemnified-label-login).

Reflex is a selective preemergence herbicide for broadleaf weed control with both soil and foliar activity, but it is only labeled for preemergence use in transplanted peppers and tomatoes. The active ingredient in Reflex is fomesafen, a PPO inhibitor and the only herbicide in this family labeled for peppers and tomatoes. Broadleaved weeds are the main targetted species of this herbicide, that also activity on nutsedge. Expect excellent control of pigweed, (including Palmer amaranth), common ragweed, nightshade, and  common purslane, acceptable control of common lambsquarters, morningglories and galinsoga, and suppression of field bindweed and nutsedge at the rate labeled for transplanted tomatoes and peppers. Use of a surfactant will improves postemergence control of susceptible annual broadleaf weeds. Note that annual grasses and some annual broadleaf weeds, including spurred anoda or horseweed, will NOT be controlled by Reflex 2SL.
[Read more…]

Filed Under: Vegetable Crops Tagged With: , ,
June 30, 2020

NJDEP Notice on Dicamba registrations (XtendiMax, Engenia, FeXapan)

State of New Jersey Dept. of Environmental Protection

 

 

The NJDEP Pesticide Program would like to share an important message from USEPA, included below, along with some key points about how the Ninth Circuit US Court of Appeals’ June 3, 2020, vacatur of three pesticide product registrations (containing dicamba as an active ingredient) impacts New Jersey’s regulated community.

  • As of June 3, 2020 sales, distribution and purchasing is prohibited for the 3 pesticide products: XtendiMax with vapor grip technology, Engenia, and FeXapan, based on the cancellation of the registrations by USEPA.
    • Distribution by the registrant, or anyone other than the registrant, is permitted only for the purposes of proper disposal (i.e. returning the product to the registrant or a registered establishment).
  • Use of existing stocks of any of the 3 products previously purchased by licensed growers and commercial applicators is permitted until July 31, 2020 and must be consistent with the previously-approved product label.
    •    USEPA includes an assessment of the risks from the use of existing stocks in the June 8th final cancellation order provided below.
    •    Nothing precludes users from stopping use prior to the July 31, 2020 deadline.
  • Distribution, sale, or use of the 3 products must be consistent with the USEPA Final cancellation order dated June 8, 2020.  Activities inconsistent with the order are considered a violation of FIFRA.
  • Where USEPA’s cancellation order allows for the continued use of existing stock until July 31, 2020, NJDEP will maintain the registrations for the 3 products until that time.  Notice will be provided to registrants for the termination of the product registrations, as applicable.

Final Cancellation Order for Three Dicamba Products (PDF) (12 pp, 10 MB)

Filed Under: Commercial Ag Updates Tagged With: ,