REMINDER: Register for Upcoming Research Field Tour in Burlington County

Rutgers Cooperative Extension of Burlington County will host a research and demonstration plot field tour at the Burlington County Agricultural Center on Wednesday, September 14, 2022. Pesticide recertification credits in CORE (2) plus categories 1A (3), 10 (3), and PP2 (3) have been approved by NJDEP.

Space is limited and REGISTRATION IS REQUIRED. Please contact Sandra Trossbach at 609-265-5051 or strossbach@co.burlington.nj.us to register by Wednesday, September 7.

soybean field

Soybeans in research plot at Burlington County Agricultural Center.

PROGRAM AGENDA

5:15 p.m. Meal and Registration (in the red market barn)

6:00 p.m. Walk to demonstration plots

6:15 p.m. How low can you go? Impact of soybean planting population on yield efficiency and crop management.

  • Bill Bamka, Agricultural Agent, RCE-Burlington County

6:45 p.m. Off-target herbicide movement and response of economically important vegetable crops to sub-lethal rates of dicamba

  • Thierry Besançon, Extension Specialist in Weed Science – Specialty Crops, Rutgers NJAES

7:15 p.m. Walk back to market barn

7:30 p.m. Beyond the active ingredient: Additives to the pesticide spray tank

  • Kate Brown, Program Associate, RCE-Burlington County

8:00 p.m. Pesticide Recertification Credits and Adjourn

The flyer for this event is available at https://events.rutgers.edu/pdfs/Flyer_Research-Tour-at-Ag-Center-2022.pdf.

Upcoming Research Field Tour in Burlington County

Rutgers Cooperative Extension of Burlington County will host a research and demonstration plot field tour at the Burlington County Agricultural Center on Wednesday, September 14, 2022. Pesticide recertification credits will be available: CORE (2) plus categories 1A (3), 10 (3), and PP2 (3).

Space is limited and REGISTRATION IS REQUIRED. Please contact Sandra Trossbach at 609-265-5051 or strossbach@co.burlington.nj.us to register by Wednesday, September 7.

soybean field

Soybeans in research plot at Burlington County Agricultural Center.

PROGRAM AGENDA

5:15 p.m. Meal and Registration (in the red market barn)

6:00 p.m. Walk to demonstration plots

6:15 p.m. How low can you go? Impact of soybean planting population on yield efficiency and crop management.

  • Bill Bamka, Agricultural Agent, RCE-Burlington County

6:45 p.m. Off-target herbicide movement and response of economically important vegetable crops to sub-lethal rates of dicamba

  • Thierry Besançon, Extension Specialist in Weed Science – Specialty Crops, Rutgers NJAES

7:15 p.m. Walk back to market barn

7:30 p.m. Beyond the active ingredient: Additives to the pesticide spray tank

  • Kate Brown, Program Associate, RCE-Burlington County

8:00 p.m. Pesticide Recertification Credits and Adjourn

The flyer for this event is available at https://events.rutgers.edu/pdfs/Flyer_Research-Tour-at-Ag-Center-2022.pdf.

Webinar for Annual Dicamba Applicator Training

BASF will host several Live Virtual Webinars for annual dicamba applicator training.  his training is required for Engenia herbicide and other dicamba products approved for over-the-top (OTT) applications on dicamba-tolerant soybean and cotton. Dicamba training is also offered through an online module.

These webinars are designed to learn about new application requirements and label enhancements for the 2021 season. Applicator training and certification can be obtained in multiple formats based on your schedule and needs. Due to COVID-19, dicamba applicator training will be primarily available through online offerings such as a self-paced training module and live virtual webinars.

Please visit http://www.engeniastewardship.com/ for training options.

Please also review PPA previous post on The 10 Best Management Practices to Avoid Herbicide Drift!

Live Virtual Webinars: 

There are a total of 6 remaining events that are scheduled to occur every Tuesday @ 10 am eastern with the next one scheduled for March 9, 2021. Attendance is limited to the first 250 attendees per event so register early for the event that best fits your schedule. Live Virtual Webinars are scheduled for:

  • March 9, 2021 @ 10 am eastern
  • March 23, 2021 @ 10 am eastern
  • March 23, 2021 @ 8pm eastern
  • March 25, 2021 @ 10am eastern
  • March 30, 2021 @ 10am eastern

Online Module: 

This option will take approximately 1 hour to complete and contains a quiz at the end of the module. Once the module is completed a certificate is displayed that should be kept for your records. You will have the option to print and/or save your dicamba certificate. It is recommended that you complete this training on a web browser through a computer with a reliable internet connection.

As a reminder only certified applicators may apply Engenia herbicide or other OTT dicamba herbicides.

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.

 

10 Best Management Practices to Avoid Herbicide Drift 

The last few weeks have been very windy, and we already received numerous calls from specialty crops growers inquiring about the risk of herbicide drift or investigating if observed crop damages may be the result of herbicide drift.

Blueberry flowers

Fig.1 Paraquat drift on blueberry flowers

Why does it seem like crops are more affected by herbicide drift in the spring? Well, mostly because this is the time when newly planted crops develop new shoots or reproductive structures that may be very sensitive to herbicide drift (Figure 1). This is also the time of the year when most postemergence herbicide are applied to control emerged weeds and subsequent new flushes. When both events coincide and if weather conditions favor herbicide drift, this could lead to disastrous injury on sensitive non target crops!

Drift is defined as physical movement of an herbicide through air, at the time of application or soon thereafter, to any site other than that intended. It can be particle drift from fine herbicide spray droplets that can travel over long distances during period of high wind. High wind speed, low relative humidity, high temperatures, small droplet size, and spray boom maintained high above the ground are factors that increase the risk of particle drift. Depending on the herbicide, application and weather conditions, fine droplets can travel up to several miles! It can also be vapor drift which results from the ability of an herbicide to vaporize and mix freely with air. Volatility of any herbicidal substance is characterized by its vapor pressure. The higher the vapor pressure of a substance, the greater its tendency to volatilize (Table 1). However, other factors such as herbicide formulation and weather conditions will influence volatility. Some herbicides classified as growth regulators (2,4-D, dicamba, triclopyr or clopyralid) are well known for the higher risk of vapor drift associated with their use when herbicide formulation and/or weather conditions increase volatility (Figure 3).

Herbicide Vapor Pressure (mmHg)
Glyphosate IPA 1.58 x 10-8
Glyphosate Ammonium Salt 6.75 x 10-8
2,4-D DMA <1.0 x 10-7
2,4-D Acid 1.4 x 10-7
Atrazine 2.9 x 10-7
2,4-D BEE 2.4 x 10-6
2,4-D EHE 3.6 x 10-6
Trifluralin 1.1 x 10-4
Clomazone 1.4 x 10-4
Table 1 Vapor Pressures for 2,4-D Formulations and Several Commonly Used Herbicides. Abbreviations: IPA, isopropylamine; DMA, dimethylamine; BEE, butoxyethyl ester; EHE, 2-ethylhexyl ester.

So, there are a few things that you need to consider reducing the risk of potentially expansive damages to sensitive crops:

  1. Select nonvolatile or low volatility herbicides to minimize the risk of vapor drift. Growth regulator herbicides such as 2,4-D, MCPA or triclopyr can be formulated as ester or amine salt. The ester formulation is notorious for its volatility; therefore, always use these herbicides formulated as amine salt to reduce the risk of vapor drift. Other herbicides than growth regulators have high vapor pressure that makes them prone to vapor drift (clomazone, trifluralin, EPTC), but either should be soil incorporated or are formulated in a way (micro-encapsulation) that will limit the risk of vapor drift.

    Beet plant

    Fig. 2 New growth chlorosis on beet. A WSSA group 27 herbicide (“bleacher”) was applied preemergence at planting in a neighboring corn field and drifted to the beet field because of high wind.

  2. Carefully read the herbicide label. The product label will provide information regarding when it is not safe to apply the product based on various parameters such as wind speed, temperature, humidity. You may also find information buffer requirement when spraying near sensitive downwind plants or information on the type of nozzle you must use for a specific herbicide.
  3. Select nozzles that produce the large size droplets while providing adequate coverage at the intended application rate and pressure. You can also select specifically designed drift-reduction nozzles (for example, drift-guard or air induction types) operate at lower pressure (15 to 30 psi) and produce large droplets that will have less potential for drift. A good source of information on droplet characteristics and operating pressure for various nozzle types is the TeeJet nozzle catalog (https://www.teejet.com/CMSImages/TEEJET/documents/catalogs/cat51a_us.pdf).
  4. Use low application pressure and drive at low speed when applying herbicides. Herbicide drift will increase with application pressure and speed…
  5. Keep the boom stable and the nozzles close to the soil as this will minimize herbicide drift but also potential injury to the crop on which herbicide is applied. You may want to consider using a shielded boom when spraying herbicide that are prone to drift or may injure your crop. Keep in mind that postemergence herbicide will provide optimal weed control when applied timely with regards to weed development. If the weeds are too tall (see the maximum weed size for each weed species on the label), then it’s too late to spray!

    Damaged crops

    Fig. 3 Damages to pepper (left), cucumber (center), and eggplant (right) caused by dicamba herbicide applied at 1/1000 of the labeled rate on soybean.

  6. Mix spray additives recommended by the label to reduce the production of fine spray droplets. Avoid tank mix ammonium sulfate with volatile herbicides as ammonium sulfate increases volatility. You can also consider the use of drift retardants that reduce drift by increasing the viscosity or surface tension of a spray solution. However, research shows that while some drift retardants may help under some conditions, the prevention of herbicide drift should primarily rely on nozzle selection, boom height, application pressure, and environmental conditions.
  7. Do not apply herbicides when wind is blowing toward sensitive plants or when wind speed exceeds 10 mph. Ideal spray conditions are when wind speed is between 3 and 10 mph. Low winds (< 3 mph) tend to be unpredictable and variable in direction and may indicate conditions that help the development of a temperature inversion. Applying any herbicide when wind speed exceeds 10 mph may result in catastrophic consequences for neighboring sensitive vegetable or horticultural crops (Figure 2).
  8. Do not apply herbicides when temperature inversion occurs. Inversions occur when warm light air rises upward into the atmosphere and heavy cool air settles near the ground, preventing the mixing of air layers. Temperature inversion will cause small-suspended droplets to form a concentrated cloud that can move long distances (up to several miles). Typically, temperature inversions start at dusk and break up with the sunrise because of vertical air mixing. To confirm the presence of an inversion, air temperature should be measured carefully at two heights out of the direct sun: 6 to 12 inches above the ground or the top of a nearly closed-crop canopy, and at a height of 8 to10 feet above the surface to be sprayed. When the temperature at the higher level is greater than the temperature at the lower level, an inversion exists. The greater the temperature difference between the two levels, the more intense the inversion, and the more stable the lower atmosphere. To test for sure, you can use smoke by burning a small amount of dry vegetation to see if the smoke dissipates or hangs low to the ground. If the smoke hangs in the air together then moves off slowly without dissipating, it indicates that a temperature inversion exists and that you do not want to spray as  long as the temperature inversion persists. Usually, temperature inversion will dissipate when temperature rises 3 degrees or more above the morning low, or when the wind speed increases to more than 3 mph.
  9. Spray when temperatures remain below 80°F to minimize vaporization and droplet evaporation. This will minimize vapor drift but also help with weed control by avoiding that spray droplets evaporate before reaching the target…
  10. Leave a buffer zone between treated fields and sensitive plants. Herbicide labels may specify the width of the buffer zone. The buffer zone will allow larger droplets to settle before reaching sensitive plants. The buffer zone may not be effective in settling small droplets.

Remember that all herbicides are capable of drift, no exception.

When spraying a pesticide, you have a moral and legal responsibility to prevent it from drifting and contaminating or damaging neighboring crops and sensitive areas. Always monitor weather conditions and their evolution carefully when spraying an herbicide. Overall, do not spray if all conditions are not suitable, and stop spraying if conditions change and become unsuitable.