NDSU Crop and Pest Report
Weeds


ISSUE 13   July 29, 2004

ERRATUM TO LAST WEEK’S ARTICLE ON WEED POCKET GUIDE

The cost for each pocket guide is $4.

 

SUPPLEMENTAL LABEL ALLOWING ADDITIONAL GLYPHOSATE PRODUCTS FOR PREHARVEST APPLICATION IN FLAX

Monsanto has issued a supplemental label for RT Master II for preharvest use in flax. This is in addition to glyphosate products already labeled and listed on page 37 of 2004 ND Weed Control Guide.

 

SUPPLEMENTAL LABELS ALLOWING WEED DESICCATION FROM GLYPHOSATE IN DRY BEANS

Monsanto has received supplemental registration for Roundup OriginalMax, Roundup UltraMax, and RT Master II for preharvest and spot-treatment of weeds in dry beans.

Roundup Original Max is the brand that Monsanto will be promoting because most of the dry bean acres are in the eastern part of the state and it is the product Monsanto has available in this geography. RT Master II is not labeled or available in MN and UltraMax may be difficult to find. NO other brands of glyphosate will be labeled for this use this year.

This label is for preharvest control of weeds only not for use as a dry bean preharvest desiccant

  1. Apply RU OriginalMax up to 22 oz/ac with AMS to improve weed control.
  2. Apply when dry bean seed is at the hard dough stage (30% grain moisture or less).
  3. Allow a 7 day PHI (preharvest interval).
  4. Not recommended for dry beans grown for seed as a reduction in germination or vigor may occur.
  5. Do not feed treated vines and hay from these crops to livestock.
  6. Do not apply through any type of irrigation system.

 

CONCERN FOR MISUSE OF GLYPHOSATE IN DRY BEANS FOR PREHARVEST USE

The EPA has set a residue tolerance for glyphosate used for preharvest weed desiccation which allowed states to issue Section 24(c) SLN labels. In 2002 and 2003, some states elected to issue a SLN registration but other states, North Dakota, Minnesota, and Michigan did not because of the potential for misuse. The label stipulates glyphosate application when dry beans are mature to desiccate weeds. The Departments of Agriculture in North Dakota and Michigan did not issue SLN registrations because it was thought that growers would use glyphosate to dry down or desiccate green dry beans to facilitate harvest thereby greatly increasing the risk of glyphosate residues exceeding tolerance. As mentioned several times earlier in this Crop and Pest Report article, this supplemental label is for weed desiccation prior to dry bean harvest. Application should be made to weeds after beans are near physiologically mature not to green dry beans. Misuse of this label may result in higher than allowed glyphosate residues in dry bean seed and if tested could result in rejection from the processors, quarantine, and legal fines. Lets follow the label.

 

PARAQUAT AS DESICCANT ON DRY PEA NOW ON FEDERAL LABEL

Use of Gramoxone Max (EPA Reg. No. 100-1074) on peas has been added to the Section 3 label for the product.  Therefore, Section 24(c) Special Local Needs (SLN) registration ND-020008 is no longer needed and has been cancelled.

 

NISSAN AND GOWAN TO FORM CANYON GROUP

Nissan and Gowan has formed a partnership for commercialization of products in the NAFTA region. Products to be included are triallate (Far-Go), halosulfuron (Permit, Sandea), and quizalofop (Assure II). Sales supporting transitional Nissan agreements with various companies will be channeled through Canyon. The new company will grow its business through product acquisitions and label expansions. Under the new agreement, Gowan will assume primary responsibility for marketing, development, registration, sales, formulation and supply chain management.

 

HORSETAIL CONTROL

Horsetail (not horseweed or maretail) is a throw back to prehistoric times because it does not reproduce by seed but by spores. It is also difficult to control because it is perennial and plants have no leaves to intercept spray droplets and absorb herbicide.

Dr. Kirk Howatt, NDSU Weed Scientist, reported some control from personal herbicide application on his fathers farm. In the summer of 2003 he applied just under 2 qt/A Remedy at 20 gpa. This converts to about 2 lb triclopyr/A. The horsetail was about 8 to 12 inches tall at application and vegetative, no reproductive were stems noticed. The stand was thick, probably more than 25 stems/sq ft.

In May 2004, he observed to the line where the treatment was sprayed. The untreated area was very thick with 12 to 16 horsetail vegetation. The treated area was almost clean of horsetail, and other broadleaf plants for that matter. I was able to find some horsetail plants, but they were deformed and had several dark-brown to black, 2- to 5-mm lesions all over the tissue. Iit was quite remarkable control considering the intensity of the population which had been established in the spot for several years. Remedy is labeled only in noncropland.

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


NDSU Crop and Pest ReportTop of PageTable of ContentsPrevious PageNext page