ISSUE 7   June 15, 2006

ERRATUM IN ND WEED GUIDE FOR PURSUIT ON CHICKPEA AND LENTIL

Page 32 of the ND Weed Guide lists Pursuit as apply shallow PPI, PRE, and POST in chickpea and lentil. Pursuit can only be applied PPI and PRE in chickpea and lentil. Pursuit cannot be applied POST in chickpea and lentil.

 

REFLEX NOW REGISTERED AND LABELED ON DRY BEAN

EPA granted federal registration of reflex on dry bean on June 1, 2006. Syngenta has labeled this use and the labeling has been approved by the ND Dept of Ag. The supplemental label is available on the ND Dept of Ag web site (web site listed on the back of the weed guide) and should also be available on on CDMS shortly.

 

2006 HERBICIDE UPDATE - PART 3

(BY HERBICIDE COMPANY IN ALPHABETICAL ORDER)

SYNGENTA:

- Agrisure GT (GA21 glyphosate resistance gene) = glyphosate resistance trait acquired from Bayer and marketing beginning in corn seed in 2006.

- Acetochlor = reregistration in mid-2006 will allow many rotational crops, such as sunflower, potato, sugarbeet, dry bean, flax, and most other crops grown in ND.

- Axial (pinoxaden+cloquinocet) = New for 2006. Registered in wheat and barley but not durum wheat. Sold as a co-pack with one container per box as Axial and the other container as Adigor adjuvant. The rate is 8.2 fl oz/A of Axial and 9.6 fl oz/A per box of Adigor or each box cover 40 acres at the registered use rate. Apply in wheat and barley at 2-leaf to boot. Excellent control of wild oat, green and yellow foxtail, Persian darnel, and other grasses. Allows tankmix of most broadleaf herbicide mixes except 2,4-D and dicamba. May control some ACCase resistant wild oat biotypes but risk of cross-resistance to other ACC-ase herbicides depend on selection pressure and use.

- Callisto = Adjuvant restrictions changed in latest Callisto label: There is no more "Do not use" statements with reference to MSO adjuvants. Statements referring to potential crop injury are still there. Flax rotation after Callisto has been from 18 months to next cropping season. Possible future registration include flax, millet, and juneberry.

New 2 (ee) label issue allowed Callisto to be applied with glyphosate. Apply Callisto at 3 fl oz/A with glyphosate on RR corn. If full adjuvant load glyphosate is used then no additional adjuvant is required but add ammonium sulfate at 8.5 lb/100 gal water. If a partial load glyphosate formulation is used then add NIS at 0.25 to 0.5% v/v. Do not add 28% nitrogen, petroleum (COC) or methylated seed oil adjuvants.

- Gramoxone Inteon 2SL = a 2 lb/gal formulation compared to a 3 lb/gal formulation of Gramoxone Max. Odor alert smells similar to decaying grass. Apply in late evening for enhanced control. Will replace Gramoxone Max.

- Prefix = (s-metolachlor) labeled for use in soybean. 2006 label is similar to Dual Magnum label. State 2ee labels recommend tankmix with Flexstar (fomesafen). Future formulations will include s-metolachlor + fomesafen together.

- Reglone = possible future preharvest registrations on pea, bean, lentil.

VALENT:

- Imazosulfuron (V-10142) = experimental SU herbicide for future registration on potato. Narrow weed spectrum but excellent control of yellow nutsedge. Data shows better nutsedge control than Permit (halosulfuron).

- Select (clethodim) registration on safflower expected. Brand names of Select and Prism will be discontinued but will be continued under generic labels: Clethodim (Microflow), AGSCO), Trigger (Albaugh), Volunteer (Tenkoz), Arrow (MAGAN), Section (Agriliance), and Intensity (UAP), others.

- Select Max with Inside Technology - greater absorption and grass control due to an enhanced formulation. Can be used on the same crops as Select. Use at 1.5X the use rate of Select.

Select Max + Assert on sunflower: Valent has issued 2(ee) label allowing a tankmix of Select Max plus Assert on sunflower for grass and wild mustard control. Apply Select Max at 9 to 12 fl oz/A + Assert at 0.6 to 0.8 pt/A. A nonionic surfactant can be added at 0.25% v/v. Do not use any other adjuvants or AMS. The 2(ee) expires 31 Dec 2006.

- Chateau 51 WDG - (flumioxazin) registered on potato and mint but product supply will be limited in 2006.

Summary of 2006 Herbicide Section 18s for ND:

Buckwheat - Poast (pending)

Flax - Spartan (approved)

MONSANTO:

- Only certain glyphosate formulation are labeled for use in preharvest dry bean, dry pea, chickpea, and flax. See weed control guide.

 

MAXIMUM SOYBEAN GROWTH STAGE FOR GLYPHOSATE

Monsanto has clarified the definition of "throughout flowering" in regard to the latest stage that glyphosate can be applied to glyphosate-resistant soybean. Soybean flowering is defined as the R2 growth stage. The R3 growth stage begins when one of the four top nodes with a fully developed leaf has a 3/16 inch long pod. With this definition, glyphosate can be applied through the R2 growth stage, but not after the R3 stage begins. Applications made after the R3 stage are off-label applications.

This clarification has two important implications. First, glyphosate applied to control late flushes of weeds or weeds escaping earlier applications cannot be delayed late into the season. In either case, earlier application timings are a good recommendation to get the best weed control and value from glyphosate.

The second implication for this clarification relates to growers or applicators planning fungicide applications to soybeans. In some of these programs, the intention is to tank-mix glyphosate with the fungicide for the ease and cost savings of a single application. Obviously, this application would be legal if made in the R1 or R2 growth stage, but would be off-label for glyphosate if made during the R3 or R4 stages. Similar limitations may occur when insecticides are applied for soybean aphids. The insecticides may be needed at a more mature soybean growth stage than allowed by the glyphosate label. Adding glyphosate to a later insecticide application for "a final weed clean-up" would also be off-label.

Applying a pesticide is certainly expensive and combining pesticides into a single application saves money. However, the pesticides also need to be applied at the correct timing to achieve their full value. If the correct timing for two pesticides occurs at the same time, it is certainly wise to tank mix the pesticides and make a single application (if the tank mix is not prohibited by either pesticide label). If the tank mix misses the best timing for either of the targeted pests, some money may easily be wasted.

Richard Zollinger
NDSU Extension Weed Specialist
r.zollinger@ndsu.edu


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