ISSUE 8    June 23, 2005

SECTION 18 FOR REFLEX ON DRY BEAN APPROVED

The long awaited ND Section 18 application for Reflex on dry bean HAS BEEN approved by the EPA. The NDDOA has issued a press release. The label can be found on the NDDOA web site or the NDSU Pesticide Certification Web site. Both web sites are listed on the back cover of the 2005 ND Weed Control Guide. A summary of use information can be found on page 29 of the 2005 ND Weed Control Guide.

 

AGDAKOTA LIST SERVE

Many of you subscribe to <agdakota> list serve which has become one of the most used and preferred avenues to quickly get critical information to consultants, agronomists, and ag professionals. Area and State Extension Ag specialists, and ND Dept of Ag staff send new pesticide registration announcements, label updates, Section 18 approvals, new pest epidemics, and a wide variety of other timely agriculture information through this list serve. If any of you are not subscribed or if you know of new hires or others that would appreciate this timely information updates, please send the persons email address to r.zollinger@ndsu.edu  to request a FREE subscription.

 

RAINFASTNESS OF COMMON LAMBSQUARTERS

Dr. Chris Boerboom, U. of WI Weed Scientist wrote an interesting article in his Pest Report last week about differential rainfastness on weeds. He noted from his field research and farm visits that foxtails and several broadleaf weeds were controlled by glyphosate after a rain event shortly after application. However, common lambsquarters was only stunted. It appears that lambsquarters might need more time to fully absorb glyphosate than other weeds. If you have a situation where lambsquarters was not controlled and other weeds were, rain could be considered as a potential cause. Different glyphosate formulations have different rainfastness periods. Page 69 of the ND Weed Control Guide gives a summary but in general:

Most Monsanto Roundup brands have a 0.5 hour,
New Syngenta Touchdown brands have a 1 hour,
Generic full adjuvant load formulations have 1 to 2 hour,
Generic partial adjuvant load formulations have a 4 hour, and
Generic no adjuvant load formulations have a 4 to 6 hour rainfastness interval.

 

NEW CEREAL HERBICIDE IN DEVELOPMENT

Axial (pinoxaden), a new cereal herbicide was introduced at the Syngenta research facilities in Stein, Switzerland, last week. Axial is a post-emergence graminicide (not a "dim" or "fop") developed for worldwide use in cereals. Axial will control a broad-spectrum of annual grasses. Pinaxaden will be formulated with cloquintocet-mexyl safener to impart excellent crop safety in both wheat and barley. Studies are being conducted to determine of this compound will control ACC-ase resistant grass biotypes.

Pinoxaden is effective on wild oat, green and yellow foxtail, barnyardgrass, and Persian darnel but does not control brome species. The application window in wheat and barley will be from 2-leaf up to pre-boot and grass weeds from 1-leaf to 6-leaf + 3 tillers. One rate will be registered for use. A specific adjuvant was developed and will be marketed with Axial.

Axial is not yet registered for sale or use in the United States or Canada. It is under joint review by the Environmental Protection Agency and Canadian regulatory authorities as a reduced-risk product. Axial will be featured as a research product in grower, retailer and distributor demonstration tours in the northern United States and in western Canada beginning June 22. Dr. Kirk Howatt has been testing pinoxaden in his state-wide grass weed control studies in wheat. Control information will be available this winter in extension meetings and updates.

 

SELECT USE IN FIELD PEA AND LENTIL

There has been some discussion on whether or not clethodim products are labeled for use in dry pea and lentil. Select, Arrow, and Prism are NOT labeled for use in these crops yet. However, they can be used in chickpea and dry bean. It will be at least 2006 before they are approved for use in dry pea and lentil. Assure II and Poast can be used in dry pea and lentil.

 

MOSS CONTROL IN STOCK TANKS AND STANDING WATER

Algae in stock and nurse tanks can be a nuisance for both animals and for chemical application especially with hard water. Adding copper sulfate to the water will take care of the problem until the tank is refilled with fresh water. The process must then be repeated.

Dissolve 1 ounce of copper sulfate in 1 pint of water in a glass jar. Add 0.25 pt/1000 gallons of water. The copper sulfate will not affect herbicide and weed control.

An alternative for nurse tanks is to paint the entire tank black. This eliminates the sunlight requirement which prevents algae growth.

 

ABSINTH WORMWOOD CONTROL IN ALFALFA - THE REST OF THE STORY

In an earlier pest report article I reported that an unusual number of inquiries were made this spring for effective postemergence absinth wormwood control options in alfalfa. I mentioned that 2,4-DB (example, Butyrac 200) could possibly be effective because some plants convert 2,4-DB to 2,4-D in the plant. Alfalfa does not make the conversion, which gives it some immunity. I discussed this with Dr. Rod Lym, who was conducting absinth wormwood control trials this year. He applied 2,4-DB to absinth wormwood over 2 weeks ago at 2 to 4 qt/A (1 and 2 lb ai/A). Th maximum use rate allowed in alfalfa is 2 qt/A. He evaluated the 2,4-DB plots for absinth wormwood control on Tuesday, June 21. There was no sign of control from either treatment. A few leaves may have been stunted in the 4 qt/A (2 lb ai/A) plot, but nothing more. Treatments that included Tordon, Banvel, Stinger/Transline. had near 100% "burn down". The rest of the story is that, with exception of Roundup Ready alfalfa, there appears to be no postemergence control option of absinth wormwood in alfalfa. Registered soil-applied herbicides ( Velpar, Sencor, Sinbar, Kerb - see page 45 in the 2005 ND Weed Control Guide) for late fall or early spring application to dormant alfalfa do not have absinth wormwood on their labels. Thus, there is nothing known to control absinth in alfalfa.

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


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