October 10, 2019

Gramoxone/paraquat Mandatory Training Required Before Use

Spraying for pests

All pesticide certified applicators must successfully complete an EPA-approved training program before mixing, loading, and/or applying paraquat.

Anyone using Gramoxone, Firestorm, Helmquat, Parazone, and other paraquat products must complete an EPA-mandated training before application.

After November 14, 2019, the EPA requires companies to have newly labeled products on the market.

 

The following are items related to the new label for paraquat products:

  • Only certified applicators, who successfully completed the paraquat-specific training, can mix, load or apply paraquat.
  • No longer allow application “under the direct supervision” of a certified applicator.
  • Restricting the use of all paraquat products to certified applicators only.
  • EPA required Online Training – users must create an account with username and password.
  • A certificate will be delivered by the end of the training after successful completion of the online exam.
  • Applicators must repeat training every three years.

For additional information and FAQs about the paraquat training go to the EPA Paraquat Training website

Filed Under: Blueberry, Commercial Ag Updates, Fruit, Landscape, Nursery, & Turf, Organic Production, Tree Fruit, Turf, Vegetable Crops, Wine Grape
September 12, 2019

Annual Bluegrass Control in Blueberry

Annual bluegrass (Poa annua L.) is an increasingly troublesome winter annual weed in some New Jersey blueberry fields. Native to Europe, this species is now worldwide distributed.

Identification and Life Cycle

Annual bluegrass

Figure 1. Annual bluegrass. Thierry Besancon, Rutgers University

Annual bluegrass starts germinating in late summer as soil temperature drops below 70°F. If conditions are favorable, it will continue germinating throughout the winter. Annual bluegrass has light green leaves with a typical boat-shaped tip (Figures 1 and 2). Leaf blades are often crinkled part way down. It will produce greenish white inflorescences (seed heads) during the spring months. Annual bluegrass is a prolific and rapid seed-producing weed.

Each plant can produce up to 100 seeds that are viable just a few days after pollination, allowing multiple germination flushes during the cool season. Annual bluegrass tends to form dense clumps in areas with moist and/or compacted soil. Poor soil drainage, frequent irrigation, excessive fertilization, use of heavy equipment causing compaction, and shade are conditions that will encourage the development of annual bluegrass.

Annual bluegrass under a microscope

Figure 2. Annual bluegrass leaf tip. Joseph M. DiTomaso, University of California – Davis, Bugwood.org

 

 

Impact

While annual bluegrass may not be a strong competitor for blueberry bushes, it forms a dense mat that will persist until late spring. This mat will prevent proper application of residual herbicides in spring by intercepting the spray solution and reducing the amount of residual herbicide penetrating into the soil. Thus, control of established sod of annual bluegrass prior to spring herbicide applications is essential for successful residual weed control in spring and early summer.

Management

As for any other weed species, preventing the release of viable seeds that will replenish the soil seedbank is a primary objective for controlling this species. Cultivation or manual digging before annual bluegrass patches become well established and before the development of inflorescence will provide control of limited infestations if continued throughout the germination period. However, the use of chemical control may be required for large infested areas or where the species has become established for several seasons.

Application of effective preemergence herbicides may prevent annual bluegrass seedling survival. However, preemergence herbicides will not effectively control emerged plants. Timely application of preemergence herbicides is very important for effective control of annual bluegrass. Herbicides should ideally be applied in late-summer / early fall before annual bluegrass seeds germinate. However, crop injury may result if pre-emergence herbicides are applied at this time when blueberry bushes are not dormant. Therefore, a fall application of a preemergence herbicide tankmixed with a postemergence herbicide is often the most practical solution and should be considered when blueberry leaves start dropping.

  • Preemergence herbicides such as oryzalin (Surflan), norflurazon (Solicam), or napropamide (Devrinol) may effectively control annual bluegrass. Application of these herbicides can be split between fall and spring applications with half of the yearly rate applied in fall and the second half in spring.
  • Simazine (Princep) can provide early post-emergence control of leaf stage plants in addition to its residual activity.
  • Pronamide (Kerb SC) is also an excellent option that will provide both residual and postemergence control of annual bluegrass. Optimum pronamide activity occurs when applications are made under cool temperature conditions (55°°F or less).
  • S-metolachlor (Dual Magnum) is also effective at controlling annual bluegrass prior to germination. However, Dual Magnum can only be applied once per cropping season and will require grower to agree to the conditions of the indemnified label (https://www.syngenta-us.com/labels/indemnified-label-search).

All preemergence herbicides require incorporation from rainfall so that the herbicide can move into the first few inches of soil where it will be protected from degradation or volatility.

When annual bluegrass has emerged before residual herbicide is applied, a postemergence herbicide should be included in the tank. Use paraquat (Gramoxone or other labeled generic formulation) plus a nonionic surfactant at 0.25% v/v of the spray solution. Glufosinate (Rely 280) is also effective at controlling emerged annual bluegrass, especially when applied under bright sunlight, warm temperature, and high humidity conditions. Do not allow glufosinate spray mist to contact green bark, as injury will occur. None of the graminicides labelled on blueberry (Select, Poast) have sufficient activity for controlling annual bluegrass. The use of glyphosate (Roundup or other labeled generic formulation) is not recommended as failure to control emerged annual bluegrass has been reported in various New Jersey blueberry fields.

 

Consult the New Jersey Commercial Blueberry Pest Control Recommendations for rates and additional information (https://njaes.rutgers.edu/pubs/publication.php?pid=E265). As with all herbicides, read and follow all label instructions and precautions.

 

 

Filed Under: Blueberry, Uncategorized
July 31, 2019

PHI for Select and Poast herbicides in peppers

The 1 day pre-harvest intervals (PHI) listed for Select 2EC, Select Max, and Poast herbicides in the pepper section of the 2019 Mid Atlantic Commercial Vegetable Production Recommendations is false.

The actual PHI as found on the most recent labels of these herbicides are as follows:

  • Select 2EC: 20 days
  • Select Max 0.97EC: 20 days
  • Poast 1.5 EC: 7 days

Errors will be addressed in the 2020 updated version of the guide.

 

 

Filed Under: Vegetable Crops
April 17, 2019

Suppression of cranberry seed germination with preemergence herbicides

Self-pollination or cross-pollination between undomesticated cranberries and selected cultivars occur frequently and produce fruits containing fertile seeds. Seedlings germinating from these seeds are off-type varieties that may have lower fruit yield potential and higher vegetative vigor. Contamination by off-type varieties may result in decreased long-term productivity of planted cranberry beds and loss of profitability for the New Jersey cranberry industry in an increasingly competitive environment.

In response to questions from New Jersey growers on the efficacy of preemergence herbicides at controlling off-type cranberry seedlings, we recently conducted an experiment at the Marucci Center for screening currently labeled preemergence herbicides.

Seeds were collected from three different varieties (Haines, Mullica Queen, and Stevens), stratified at 3°C for 2 months, and seeded on Petri dishes containing preemergence herbicide mixed in agar. The trial was replicated 5 times and two different runs were conducted during the winter 2018-2019. Cranberry seed germination was quantified several times a week and the experiment was terminated by 40 days after seeding cranberry seeds.

Three different petri dishes of seeds under a microscope

 

 

 

 

 

Results: Callisto, regardless of rate applied, did not provide any control of cranberry seed germination compared to the untreated check. Similarly, Evital 5G did not reduce seedling emergence more than 17% when used at the highest labeled rate (160 lb/A). Devrinol DF-XT had higher activity, reducing seed germination by 30% at 12 lb/A and by 50% at 18 lb/A. However, only the 12 lb/A rate is labeled for sandy beds. Casoron 4G was the most effective treatment with complete inhibition of cranberry seed germination at 50 or 100 lb/A. Similar results were noted by Dr. Jed Colqhoun in Wisconsin on cranberry grown on peat plugs for Casoron and Callisto. However, Devrinol was noted having no activity on cranberry seed germination in the WI study. This might be caused by organic matter binding of the herbicide in peat plug, which is less of a problem in agar. The study will be continued this summer by looking at germination of seed grown in a mix of sand and peat moss and treated with some of the preemergence herbicides mentioned here.

Graph of cranberry germination after treatment

These results highlight the need for rotating preemergence herbicide with different modes of action, not only for preventing the onset of herbicide resistant weed species, but also for expanding the spectrum of weeds controlled by these herbicides, including off-type cranberry seedlings.

 

Filed Under: Cranberry
April 15, 2019

Optimizing preemergence weed control in established blueberry  for 2019

Several long-residual herbicides with different modes of action (MOA) are labeled for established blueberry. 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 preemergence herbicides.

Casoron (dichlobenil) is a cellulose synthesis inhibitor recommended for fall application to control many annual and perennial broadleaves, grasses and yellow nutsedge.

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 very sandy or wet soils.

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. Fall or spring application of Kerb can also be considered for perennial quackgrass suppression.

Solicam (norflurazon) is a pigment inhibitor that may be applied in fall or spring primarily for annual grass and sedges control. Solicam may also provide partial control of many broadleaf weeds as well as of yellow nutsedge.

Chateau (flumioxazin), Zeus XC (sulfentrazone), and Zeus Prime XC (sulfentrazone plus carfentrazone) are PPO inhibitors with activity against many broadleaves when applied preemergence in fall. They also have some postemergence activity on newly emerged seedlings of annual weeds.  Chateau has a 7 day preharvest interval (PHI) and Zeus/Zeus Prime have 3 day PHI, and can therefore be applied later in the season to extend preemergence broadleaves control into late summer.

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.

Matrix (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 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.

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. Dual Magnum has a shorter residual activity compared to other blueberry residual herbicides but will provides good yellow nutsedge, eastern black nightshade and pigweed control.

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 preemergence herbicides before bud break with little risk for crop injury.

 

Filed Under: Blueberry
February 27, 2019

2019 Mid-Atlantic Field Crop Weed Management Guide

The 2019 updated version of the “Mid-Atlantic Field Crop Weed Management Guide” is available. This guide is collaboratively developed by weed scientists from Penn State, , Univ. of Delaware, Univ. of Maryland, Rutgers University, Virginia Tech, and West Virginia Univ.

The guide covers weed management  for field corn, sorghum, soybean, small grains, and forage and pastures. Information concerning the use,  restrictions, and recommendations of burndown, preemergence, and postemergence herbicides labeled on these crops can be found in the guide, including relative effectiveness data from locally conducted research. Description of the various premixes as well as guidance for  managing troublesome weeds are also part of the guide.

The guide  can be ordered on-line at https://extension.psu.edu/mid-atlantic-field-crop-weed-management-guide. Available on-line are the printed copies for $25; an enhanced pdf copy for use on computers and tablets for $15 or both a hard copy and pdf for $35.

A sample of the guide can be downloaded at the following address https://extension.psu.edu/downloadable/download/sample/sample_id/880/

Filed Under: Field, Forage & Livestock, Vegetable Crops