June 30, 2020

Command 3 ME Label Change for Lima Beans

FMC Corporation, Rutgers University and the New jersey Department of Environmental Protection collaborated on labeling Command 3ME for use on lima beans through the release of a 24(c) Special Local Need Label. The label is available online at https://www.cdms.net/ldat/ld324024.pdf.

In the past, the Command 3ME label allowed use in lima beans, but this use was removed a couple of years ago. This new labeling essentially restores the previous use pattern. This labeling only applies to FMC’s brand of Command.

Command 3ME can be applied at 4 to 6 fluid ounces immediately after seeding, with the lower rate recommended for coarse-textured soils. This low rate does not provide control of pigweed species or most broadleaf weeds (including Palmer amaranth), rather it provides early-season weed suppression that allows for improved control with cultivation. This label also allows for planting lima beans 60 days after application in a preceding crop. This allows use for Command use in peas and planting lima beans at least 60 days later.

Currently, Command 3ME received a 24(c) SLN label for use on lima beans only in New Jersey, Delaware, Maryland, and Virginia.

Filed Under: Commercial Ag Updates, Vegetable Crops Tagged With: , ,
June 12, 2020

Carolina redroot control in cranberry with Callisto® herbicide

Figure 1. Carolina redroot infestation in cranberry bog

Carolina redroot (Lachnanthes caroliniana), a native plant of New Jersey Pine Barrens, has becoming an increasingly troublesome weed for cranberry production across the state (Figure 1). Carolina redroot is a perennial herbaceous weed species belonging to the Haemodoraceae family. It competes for nutritional resources during the cranberry growing season, and its rhizome serve as a feeding resource for wintering waterfowl that can cause severe uprooting damages of cranberry vines when bogs are flooded. Carolina redroot blooms after cranberry and its flower is very attractive to pollinators (Figure 2) at a time when insecticides may be applied to cranberry bogs. Additionally, the desiccated seed head of Carolina redroot can be picked up by harvesting equipment and broken in small pieces that will be difficult to eliminate during fruit processing.

Invasive species

Figure 2. Carolina redroot is very attractive for pollinators… at a time when insecticides may be applied!

 

Studies have been conducted at Rutgers since 2017 to screen various herbicides that can properly control or suppress Carolina redroot without injuring cranberry. In greenhouse screenings, Callisto® 4SC (mesotrione) has provided good control of Carolina redroot while maintaining excellent crop safety. Callisto is a systemic herbicide that will cause bleaching of weed leaves by indirectly inhibiting the biosynthesis of carotenoid that protect chlorophyll from photodegradation. Cranberry is highly tolerant because it is capable of rapidly metabolizing the mesotrione. Callisto will not kill Carolina redroot outright, but will weaken it and stunt it, preventing the formation of the floral stem (Figure 3). We are still evaluating if continued annual use of Callisto for two or three years will completely eliminate Carolina redroot.

Bee pollinating flower

Figure 3. Bleaching and stunting of Carolina redroot floral stem following Callisto applied at 4 fl oz/A

Spot application: ideally, Carolina redroot should be controlled before it starts colonizing large areas of a cranberry bogs. Therefore, scouting and mapping is a crucial and necessary step to detect early infestation that be treated with spot application of Callisto. We obtained in 2019 a 24(c) Special Local Need label for spot application of Callisto at rates that will help controlling perennial weeds such as Carolina redroot. We recommend mixing 3.2 teaspoons of Callisto per gallon of water and add crop oil concentrate (COC) at 1% v:v or 2.5 tablespoon per gallon of water. This rate will allow to spray up to 15 gallons of solution per acre while not exceeding the maximum labeled rate of 8 fl oz per acre and per application.

Stunted plant

Figure 4. Reduction of Carolina redroot biomass with spot application of Callisto at three different rates and two different timings of application

At this rate and if Callisto is applied when Carolina redroot emerge above cranberry canopy in early to mid-June, we observed a reduction of Carolina redroot biomass by 70% at the end of the season. Higher rate will not significantly increase Carolina redroot suppression and later application in mid-July will not be effective (Figure 4). Spot applications will be sprayed with a backpack or hand-held sprayer that needs to be properly calibrated. Calibration of hand sprayers is determined by the walking speed of the applicator and the discharge rate from the nozzle along with the concentration of the material in the tank. Use great care in spot-treating. The difference between an 8-oz application and an 80-oz application is only seconds on the trigger. Spot treatments made to runoff will exceed the maximum application rate.

Stunted plant

Figure 5. Annual sedge control with Callisto applied at 4 fl oz/A

Broadcast application: in bogs where Carolina redroot has colonized large areas, chemigation using irrigation sprinklers or boom application should be considered for broadcasting Callisto.  Callisto can be applied at up to 8 fl oz per acre per application, but we observed bleaching and stunting of Carolina redroot floral stem with Callisto at a 4 fl oz/A rate applied with a regular boom. If chemigating, we recommend Callisto to be applied at 8 fl oz/A. Always use a COC adjuvant at 1% v:v. All application should be made when Carolina redoot leaves emerge from cranberry canopy but before the on-start of bloom because COC adjuvant may injure cranberry flowers and reduce pollination. A second application at 8 fl oz/A can eventually be applied after cranberry bloom to help suppressing Carolina redroot. Callisto will also help controlling sedges or rushes (Figure 5). Callisto applications cannot exceed 2 per acre per year and a maximum of 16 fl oz per acre per year.

 

Filed Under: Cranberry Tagged With: , , ,
June 1, 2020

Residual Weed Control in Cabbage and Other Cole Crops

Good weed control in transplanted and seeded cole crops requires planning and the use of pretransplant or preemergence herbicide applications.

Cabbage treated pretransplant with Goal and never cultivated.

Cabbage treated pretransplant with Goal.  The crop was never cultivated.

Preplant incorporate Treflan HFP at 1 to 1.5 pt/A for seeded and up to 2 pt/A for transplanted, or apply Dacthal 6F at 6 to 14 pt/A or Prefar 4E at 4 to 9 qt/A preemergence or post-transplant to control annual grasses and certain broadleaf weeds. Choose Dacthal or Prefar in early spring when soils are cold and wet when Treflan may cause temporary stunting. Please make sure to check the label before mixing as these herbicides are registered for use only on certain cole crops.

Goal 2XL and GoalTender 4F are labeled for transplanting ONLY!.  Goal 2XL can ONLY be used pretransplant whereas GoalTender 4F can be used pre-transplant or post-emergence with a 24(c) Special Local Needs label on broccoli, cabbage and cauliflower in New Jersey (NJ 24(c) SLN GoalTender 4F). Build beds, spray, and transplant through the herbicide barrier. Use Prefar or Dacthal post-transplant for grass control. Treflan or Dual Magnum applied preplant incorporated may increase the risk Goal injury. Do NOT cultivate unless weeds appear. Incorporation of Goal reduces or eliminates the effectiveness of the product for weed control. Goal and GoalTender are registered for use only on certain transplanted cole crops.

Dual Magnum 7.62E has a 24 (c) Special Local Needs label for use on cabbage in New Jersey. Use Dual Magnum at the rate of 0.5 to 1.33 pt/A  depending on soil type. Use the lower rate on soils that are relatively coarse-textured or low in organic matter; use the higher rate on soils that are relatively fine-textured or high in organic matter. Apply to weed free soil in transplanted cabbage after transplanting, or to direct seeded cabbage when the seedlings have developed 3 to 4 true leaves. The delayed use in directed seeded cabbage reduces the risk of slight temporary stunting of the crop. Dual Magnum controls annual grasses, nightshade species, and galinsoga. Yellow nutsedge will be suppressed or controlled at the rates and use patterns on the Dual Magnum label for cabbage. To obtain a label, an indemnification agreement must be filled out on line agreeing not to hold the manufacturer responsible for crop damage. Obtain a copy of the label and complete the indemnification agreement on the Syngenta website. Register or sign in, select state and product, and submit. You will then be asked to select your crop before accepting or not the waiver of liability and indemnification agreement. You must have a copy of this 24(c) label if you want to use Dual Magnum on cabbage!

Consult the 2020/2001 Mid-Atlantic Commercial Vegetable Production Recommendations for rates and additional information.

 

Filed Under: Vegetable Crops Tagged With: , , , ,
May 7, 2020

Weather Conditions and Herbicide Performances

Temperature and Herbicide Performance

With air temperatures remaining relatively low this spring, growers have asked about how temperature may affect the efficacy of herbicide applications. The effect of cool temperatures on weed control efficacy will depend on the type of herbicide application, the rate applied, and the physiological status of the target weed.

Summer annual weeds such as lambsquarters or crabgrass require good soil moisture and soil temperatures between 60 and 70F to start the germination process. It is important for preemergence applications to be effective that residual herbicides are applied before soil reaches this optimum temperature range. Of course, herbicides should never be applied on frozen ground. However, cool and wet weather can increase the potential for crop injury with preemergence herbicides because of slower herbicide metabolization by the crop.

Grass and broadleaf weeds are controlled more effectively when plants are actively growing. The ideal air temperature for applying most post-emergence herbicides is between 65°F and 85°F. At lower temperature, weed control will be slower, especially with systemic herbicides such as glyphosate, Poast, Select, or Sandea that are more slowly absorbed and translocated by the weeds compared to applications at higher temperatures. Also, slower herbicide uptake by the weeds will increase the required rainfast period and slows the development of herbicide symptoms on the plants. Weeds that have been damaged (by mechanical equipment for example) or that are under stress (drought, water excess) at the time of herbicide application or before herbicide has properly translocated will not be properly controlled. Reduced herbicide rate treatments are less likely to provide acceptable control under adverse conditions than when plants are actively growing. Thus, it is best to avoid applications of postemergence herbicides during periods of cool temperatures (<40°F at night; <55°F during the day).

High temperatures increase the loss of volatile herbicides. 2,4-D ester or dicamba will rapidly evaporate at temperatures above 80°F, causing. The use of such ester formulations should be restricted to fall, winter, and early spring because sensitive plants are not present and lower temperatures reduce vapor drift hazard.

Adjuvants may also affect crop safety and weed control. Oil additives may increase risk of crop injury but may be necessary for greatest weed control. Refer to each herbicide label for specific information on adjuvant use during stress conditions. Use an oil additive if risk of crop injury is acceptable for those herbicides that allow use.

Ideally, you should be waiting for the right conditions to apply the herbicide. However, if weeds are at growth stage that require a rapid intervention, select a herbicide with excellent efficacy for controlling your target weeds. Remember that the efficacy pf postemergence applications is mainly dictated by weed size… spraying weeds beyond the size range recommended on the label will result in porr weed control.

Rainfast Period

The rainfast period is the minimal period of time that must elapse between herbicide application and subsequent rainfall to ensure good postemergence herbicide performance. Generally, herbicide rainfast ratings are based on good growing conditions (table 1). Poor conditions may require a longer interval between application and any rainfall to ensure adequate herbicide translocation within the weed before the herbicide is washed off. For many herbicides, any amount of rainfall soon after spraying has the potential to reduce absorption, translocation, and subsequent weed control. If you apply herbicide and it rains before it’s rainfast, herbicide performance will be reduced.

Table 1. Rainfast time for postemergence herbicides commonly used in New Jersey Specialty Crops.

*Rainfall will improve control from root uptake.

**Rainfall within 6 hr. after application may reduce effectiveness. Heavy rainfall within 2 hours after application may wash the chemical off foliage and a repeat treatment may be required.

Filed Under: Blueberry, Fruit, Tree Fruit, Uncategorized, Vegetable Crops, Wine Grape Tagged With: ,
April 20, 2020

Safely Using Herbicides in Re-Used Plastic Mulch

Crops covered with plastic protection

Plastic mulch and trickle irrigation are expensive. Re-using the mulch for a second crop after the first can be an effective way to spread the cost.

Plastic mulch and trickle irrigation are expensive. Re-using the mulch for a second crop after the first can be an effective way to spread the cost. When the cost of supplies and labor are evaluated, re-using a field with trickle irrigation and black plastic mulch is an attractive idea, but weed control can be a problem.

The herbicides used under the plastic and between the rows of mulch for the first crop must be safe and labeled for use in the second crop. Prefar applied at 6 quarts per acre in a band when the mulch is laid is a good choice for under the plastic. Prefar is labeled for many vegetable crops but ALWAYS check the label to see if the crop you plan to plant is listed on it. Prefar and Gramoxone plus NIS (nonionic surfactant), applied as a shielded banded spray between the rows of mulch, are also labeled for a wide range of vegetable crops. Be sure post plant applications of Gramoxone plus NIS are shielded, applied at low pressure, and a low drift agent is used.

Often the greatest challenge is eliminating the first crop and any weeds in the field prior to planting the second crop in the mulch. No herbicide should be sprayed broadcast over the mulch except Gramoxone, which is quickly broken down by sunlight.

Roundup and other glyphosate products should NEVER be used on plastic mulch. Gyphosate has no residual activity due to strong and immediate adsorption by the soil where it is slowly broken down by soil microorganisms as a food source. On plastic mulch without contact with the soil, glyphosate does not easily wash off the plastic with rain or irrigation. The simple act of letting the root ball in contact with the plastic during transplanting can expose the crops roots to enough glyphosate to cause lasting injury and crop loss!

Residual herbicides must be banded between the rows of plastic mulch, NEVER sprayed broadcast over the mulch. Broadcasting residual herbicides over plastic mulch can increase the risk of washing the herbicide from the plastic into the planting hole when it rains or if you irrigate overhead. Herbicide concentration in the planting hole will be way higher than the safety threshold for any crop! If the herbicide from 1 square foot of plastic washes into the 3 square inch planting hole, that will increase increase 48 times the intended herbicide rate in the planting hole!!! You can certainly not expect good crop safety from any herbicide at 48 times the intended rate! Keep all residual herbicides off the plastic mulch.

In summary, the greatest weed control challenge in re-used plastic is weeds growing under and through holes in the mulch. Gramoxone is broken down by sunlight, so it can be used to kill the first crop and emerged weeds. Consider fumigating under the mulch with a water soluble fumigant injected through the trickle irrigation to provide weed control in the second crop. Disease control may be another added benefit. Remember to wait until the fumigant has dissipated before planting.

Filed Under: Vegetable Crops Tagged With: , , ,
March 16, 2020

2020 Recommendations for Preemergence Weed Control in Established Blueberry

With T3 stage scheduled for late March, it’s really time now to apply your preemergence herbicides before blueberry bud break!

Preemergence 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 incorporate the herbicide in 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 preemergence 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 preemergence 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 therefore be used in spring to control ALS-resistant horseweed at the rosette stage.

Consult the 2020 Commercial Blueberry Pest Control Recommendations for New Jersey 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 February 25, 2020.

Filed Under: Blueberry, Uncategorized Tagged With: , ,