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ISSUE 11  July 11, 2002

 

GLYPHOSATE ON FIELD CROPS INTENDED FOR FORAGE

With dry conditions causing poor crop and a serious shortage in livestock feed many are considering using existing crop for forage. There is misinformation being spread in the state. Some of the concerns with the extremely dry conditions are about nitrate levels in the crop foliage. A rumor is circulating about glyphosate being used on small grains to kill the crop and supposedly reducing the nitrate levels of the crop so that it can be hayed or grazed by livestock. Glyphosate has an 8 week grazing and haying restriction for broadcast applications in small grains. Do not confuse the 7 day after application preharvest restriction on glyphosate labels. Preharvest applications are made with the intention of harvesting mature grain - not to hay, graze, or feed. To our knowledge, there is no truth or any valid reason that glyphosate should lower nitrate levels in plants.

 

GRAMOXONE MAX ND SECTION 24(c) FOR PEA SEED PRODUCTION

The ND Dept of Ag has issued a special local needs (SLN) registration to Syngenta Crop Protection, Inc., allowing North Dakota producers of dry peas and succulent peas grown for seed to use the herbicide Gramoxone Max as a desiccant and for control of late-season weeds.

Uniform and quick desiccation of pea plants is critical in the production of high-quality pea seeds and no other desiccants are registered for use in peas that do not negatively affect the germination of seeds has prompted this SLN registration.

Applicators must follow all instructions, precautions and warnings on the product label and have a copy of the SLN supplemental labeling in their possession during application.

 

SYNGENTA ANNOUNCES NEW NAME FOR CORN HERBICIDE

Syngenta Crop Protection announced a new brand name for a corn herbicide in development that promises to deliver one-pass pre-emergence weed control on most corn acres and improved weed resistance management for U.S. corn growers. The new brand, LUMAX, is powered by the active ingredient in Callisto and a grass control product in corn. The LUMAX name is derived from the word "lumen," meaning light, and "maximum," meaning the most that can be achieved. In short, LUMAX means "maximum light." The proposed LUMAX label will encompass a broad spectrum of both grass and broadleaf weed species, several of which have developed resistance to triazine and ALS-inhibiting products, including waterhemp, lambsquarters, velvetleaf, pigweeds and ragweeds, along with most annual grass species. EPA registration for LUMAX is expected in time to allow for use in the 2003 season. LUMAX will be labeled for pre-emergence application for the control of most annual broadleaf and grass weeds.

 

EPA TO IMPROVE FLEXIBILITY OF SECTION 18 PROCESS

At the May meeting of the Pesticide Program Dialog Committee, EPA proposed three reforms to the Section 18 process.

The reforms are expected to be published in the Federal Register for public comment during summer, 2002 and will be implemented, on an interim basis, for the 2003 growing season.

 

NIGHTSHADE IDENTIFICATION

For many years it was supposed that ND had 3 types of nightshades: Eastern black, hairy, and cutleaf. Hairy nightshade is easy to identify because it is the only nightshade where plants are covered with hairs. Cutleaf is relatively easy to identify because it grows flat (prostrate) to the ground and the leaves have many small lobes which is fundamentally different than ovate leaf shape of the others. The berries of both hairy and cutleaf remain green and do not turn black/dark purple like black or E. Black nightshade.

Recently, populations of black nightshade were identified and results in confusion in trying to identify Eastern black from black nightshade at an immature stage. From available information the only methods to separate black from E. black was to wait until berry formation where differences in point of berry attachment and calyx could be used. This is useless when trying to identify at the seedling stage before herbicide application.

Take Heart! A possible solution! A sharp consultant caught some obscure wording in a weed ID book called Ontario Weeds. In this book Eastern black nightshade leaves were described as thinner, lighter green and "translucent" to light. The leaves of black nightshade were described as thicker, darker green, and "opaque" to light. If this were true this could be a great help to separate these two.

Why does it matter? Potato growers have the herbicide Matrix (rimsulfuron), also a component in Accent Gold, Basis Gold, and Steadfast in corn. University research shows Matrix gives >95% control of Eastern black nightshade, 50%-99% hairy nightshade control, and tolerant to black nightshade. If a grower applied Matrix intending to control E. black nightshade but instead had a large proportion of black nightshade, of coarse it wouldn’t work. The grower may claim the herbicide didn’t work when in actuality it was a weed that was tolerant.

Also, resistance to Pursuit and Raptor has only been reported in Eastern black nightshade. It would be good to keep a watch to see if the resistance stays within the E. black nightshade species or will occur in the black nightshade complex. Presently, the Pursuit and Raptor labels claim control of hairy, black, and eastern black nightshade.

Let verify this information in Ontario Weeds. This summer if you come across something which you assume is eastern black nightshade, hold a leaf up to the sun and see if it transmits light (translucent) or if it is opaque (does not let light through) to light. Follow the plants on through berry production and match berry attachment and calyx form to verify if it black or eastern black nightshade. I appreciate a short email or phone call on your results. Thanks.

Richard Zollinger
NDSU Extension Weed Specialist
rzolling@ndsuext.nodak.edu


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