ISSUE 9 June 30, 2005
ND SLN REGISTRATION CANCELLED
On June 24, 2005, the North Dakota Department of Agriculture cancelled Special Local Needs (SLN) ND-970002. This registration had allowed used of Velpar DF Herbicide (EPA Reg. No. 352-581, active ingredient hexazinone) on alfalfa to control weeds.
APPLICATION WINDOW FOR 2,4-D
Some have noticed that the application window for 2,4-D has been changed in the small grain section of the 2005 ND Weed Control Guide. Previous versions of the Guide listed the application window for 2,4-D in small grains as 5-leaf to prior to boot. The 5-leaf stage was listed to provide maximum safety to wheat and barley from labeled rates as high as 1.33 pt/A. Most herbicide labels, however, allow application at the 3-leaf stage, or beginning of tillering. The application window of 2,4-D was changed in the weed guide because low rates of 0.5 to 0.75 pt/A are normally used in ND and also to more accurately reflect label directions. DO NOT spray before the tillering stage of small grains - there must be at least one tiller on the plants.
HERBICIDE MODE OF ACTION AND SYMPTOMOLOGY WEB SITES
A caller asked for a good web site showing herbicide mode of action and accompanying symptomology pictures of key symptoms on crop plants. I shamingly said I did not but have since repented. There is a vast assortment of good printed material in extension bulletins, guides, and circulars but I had not yet scanned the electronic cosmos. NDSU Extension Service has:
W-1141, Herbicide and Nonherbicide Injury Symptoms on Spring Wheat and Barley - only in print
A-1085, Herbicide Mode of Action and Sugarbeet injury Symptoms
NCR377, Herbicide Mode of Action and Injury Symptoms (Corn and Soybean) - only in print form
NCR158 Herbicide Symptoms in Dry Edible Beans - only in print form
Go to: http://www.ext.nodak.edu/extpubs/weeds.htm for these and other weed and herbicide publications available through the NDSU Extension Service.
The North Central Weed Science Society (NCWSS) has developed a warehouse web site to access extension publications from most mid-west universities. Go to: http://www.ncwss.org/ , Click on "Publications", then "Midwest Web Extension Publication".
From there you can get a large variety of extension materials, including herbicide mode of action and pictures of herbicide symptomology.
IMPORTANT TIP FOR DRY EDIBLE BEAN MICRO-RATE TREATMENT
Page 29 of the weed guide lists the NDSU micro-rate herbicide treatment for dry bean. I have been getting many calls about different parameters of this treatment. THE MOST IMPORTANT piece of information about this treatment is that weeds MUST be less than 2 inches tall for this treatment to work. Most callers failed to read that part of the table and assume it will control large weeds. IT WILL NOT. The rates of the herbicides have been reduced so much they will only control small weeds. The micro-rate was developed to control both hairy and eastern black nightshade plus some other sensitive weeds like pigweed, mustard, cocklebur, marshelder, and sunflower. Weeds that may escape are wild buckwheat, large ALS-resistant kochia, large common lambsquarters, large ragweed, and biennial wormwood. Growers should consult the weed control ratings on pages 122-125 of the weed guide to determine how effective each herbicide is to each weed.
NDSU Extension Weed Specialist