Maryland Weed Reporter
http://www.agnr.umd.edu/users/weed/weedrep2.htm
Fall 1996; Volume 12, No. 2
| The Maryland Weed Reporter is written to bring you up to
date on changes in the agricultural chemical industry, new
products on the horizon, new weed problems you should be
aware of, suggestions for managing weeds at certain times of
the year, and other topics in our battle against weeds. This
edition will discuss changes in the agricultural chemical
industry, some of the new changes we are incorporating in our
Pest Management Guide (EB 237), and discuss steps you can
take to prepare for next year.
Ronald L. RitterExtension weed control specialist |
|
Summer Issue of Maryland Weed Reporter Weed Science Home Page Most of you have probably heard that CIBA and Sandoz are planning to merge into one company called Novartis. The FTC put a halt on this merger in the U. S. They felt it would make Novartis too strong a presence in the corn market. Last week, it was announced that BASF had purchased the rights to dimethenamid (Frontier and Guardsman) and dicamba (Banvel, Clarity, Marksman). BASF will have world-wide rights to sell dimethenamid products, but will only have dicamba products in the U. S. and Canada. Novartis will have dicamba products outside of this area. Hold on to your old CIBA and Sandoz hats --they will become collector items!
It was also announced last week that Monsanto purchased Asgrow seed company. Asgrow is key player in the Roundup-Ready soybean market. At this point, Monsanto owns Hartz and Asgrow seed companies, both suppliers of Roundup-Ready soybean seed.
We will be incorporating a number of changes to the new edition of EB 237. The following lists a few things you should be aware of. (Note that EB 237 is available for purchase through the Cooperative Extension Service. See CES Publications Available for Order page, Agriculture, and follow the links at the bottom of that page for ordering information. You will need to use your back button in your browser to return to the Maryland Weed Reporter.)
We've completely updated the "Guide to prepackaged mixes" to reflect all of the new package-mix products in the market-place. The "Guide to single active ingredient herbicides" has been completely updated as well to reflect products we left out last time and new ones added since last year. Also, we've added another column in this table to reflect the mode of action of each product. This can be extremely helpful when selecting products with different modes of action for resistance management.
The corn section has been completely updated to reflect changes in available products and tank-mixes. For instance, Roundup Ultra instead of Roundup is listed throughout. Rates for package-mixes such as Bicep II, Bullet, Guardsman, Harness Xtra, and Surpass 100 are now either listed under product per acre or listed in the remarks section. Products and rates have been updated to reflect current standards such as Frontier 6EC instead of Frontier 7.5EC or new tank-mixes with Basis. New entries have been added such the postemergence use of Sencor and a section on Liberty-Link corn. We've also added new crops to the rotational restriction tables (lima beans, onions and tobacco), added a table to reflect the early postemergence use of preemergence herbicides, and another table for tank-mix partners with postemergence herbicides.
We've updated the efficacy tables to reflect only trade name products. Grazing restriction tables have been updated. Spiny amaranth has been added to the efficacy tables.
This section has also been updated to reflect changes in the market-place. Remarks for Dual II, Frontier, and Micro-Tech/Partner now reflect the fact that Concep or Screen treated seed can be used. Frontier has been recently labeled for use in sorghum and has been added. Peak, a new postemergence product, has also been added.
This section has been revised to reflect current changes in Harmony Extra and Hoelon labeling. Also, Peak has been added as a new postemergence product.
As mentioned in the corn section, the rotational restriction tables have been expanded to include lima beans, onions and tobacco. The efficacy tables have been revised and expanded to include Roundup Ultra, Stellar and Synchrony. In the text section, we've added entries for Command 3ME, Sencor for use in no-till as a knock-down product, and Stellar. Old products like Gemini have been deleted while other products like Frontier 7.5EC have been updated to reflect new formulations (Frontier 6.0EC).
Nothing new to report in the sunflower section while the tobacco section has been revised to reflect the loss of Paarlan and the addition of Command 3ME.
If you haven't found it, the last page of the "Weed Control" section lists "Vegetable Herbicide Rotation Restrictions." It lists many of the vegetable herbicides and restrictions placed upon them. Once again, this table has been updated and revised to reflect current changes in labeling. EB 237 is a great guide full of worthwhile information! I constantly try to get it in people's hands by promoting it during the Winter meetings. I'm sure the 1997 edition will be the best yet!
Fall is generally a great time to apply systemic herbicides. Why? Because they translocate down to the storage tissues of perennial plants, hopefully killing them in the process. What should you use?
My experiences with plants like Canada thistle, sweet potato vine, trumpet creeper and horsenettle have shown that you need at least a 1.5 qt/A rate of products like Banvel or Roundup Ultra to get good control. I generally recommend 2.0 qt/A. You can mix and match. For instance, one could use 2.0 qt/a of Roundup Ultra or 2.0 qt/A of Banvel. If you want, 1.0 qt/A of each product tank-mixed together does as good a job. Banvel or Roundup generally work best. You could substitute 2,4-D, but we haven't seen the best activity with 2,4-D in comparison to Banvel or Roundup Ultra. If substituting, I would use 1.5 qt/A or Roundup Ultra or Banvel and mix 1 pt/A of 2,4-D with it. Keep in mind a few key things! If rotating to small grains, only use Roundup Ultra. The residual activity of 2,4-D or Banvel may result in small grain injury. If using conventional tillage, allow the Roundup to do its job! In other words, wait 7 to 10 days before you plow or disc the field.
Bermudagrass is another pest I get many calls on. Early versions of the Roundup label suggested a 5 qt/A rate when Fall applied for control of bermudagrass. Lately, a 2 - 3 qt/A rate has been suggested. With either rate, I don't feel that you'll be satisfied with control the following year. Bermudagrass is a weed you'll need to work on for a few years to see a reduction in plant population. At this point, Roundup Ultra will be a starting point in your program. I would stick with the 2 - 3 qt/A rate. Make this application as soon as possible after corn harvest, while the bermudagrass is still somewhat green. Next year, if considering corn, I would suggest a SR hybrid. SR stands for sethoxydim (Poast) resistant. It allows you the opportunity to apply Poast over-the-top of corn. If planting soybeans, most of the post grass products (Assure II, Fusilade DX, Poast Plus, Select) do a nice job, although 2 applications may be necessary. Roundup-Ready soybeans are another alternative. Once again, do not expect complete eradication in a 12 month time period. It may take 2 - 3 years before the population is significantly reduced.
Spiny amaranth is another weed I've been getting a lot of calls on lately. It is an annual. It will die after a few hard frosts. There is no sense in spraying it now. Wait until next year, but hit it when it's small!
Finally, for those of you planting small grains, annual ryegrass is up. I would suggest 1.5 pt/A of Roundup Ultra to knock it back this Fall. You can always come back with Hoelon in the Spring. Also, wild garlic has emerged, but I doubt if all of it has come up. Early applications of Harmony Extra do a good job, but if you get another flush next year, be prepared to spray again.
The College of Agriculture and Natural Resources, and especially the Cooperative Extension Service, has a lot of information on the world wide web. I was talking to Steve Rothman, Head of the Office of Information and Communications Technology, viewing what CES has on the web. It's impressive!
November 13th and 14th. College Park, MD.
(I will be out of town for the meeting)
CCA School
November 19, 20 + 21 - Dover, DE
To Reach Me by Phone:
Office voice mail -- 301-405-1329
Truck phone -- 301-412-9858
Home -- 301-490-4959
Email-- rr24@umail.umd.edu
*Remember - leave me a phone number where you can be reached!