December,    1999
Volume 15, No. 2
  

MARYLAND WEED REPORTER 

With the year coming to a close, I thought I'd put out one last MARYLAND WEED REPORTER to wrap up this year and mention some exciting things for the new year.

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1999 Results of Weed Control Research

All of you should have received a copy of our results book from 1999. I realize it's big and awkward for many of you to use. Yet, it contains a lot of useful information. There are a couple of different ways to tackle the book. One way would be to look at the titles of the studies. If you are interested in weed control in a certain crop, you could look in the titles for that specific crop and then go to the trial(s) and see how the products performed. Another way to use the book is if you were only interested in preemergence or postemergence herbicides, once again look at the titles and go to the respective application timing for the specific crop. A third way to use the book is to look for a specific weed in the title such as johnsongrass, spurred anoda, giant ragweed, triazine-resistant weeds, etc. Then go to the respective study and see how the products performed on that specific weed. Some of the titles also list the type of crop you may be looking for such as Roundup-Ready, Liberty-Link or STS. Finally, in the back of the book is a chemical index. If you are interested in a specific herbicide, look the product up and then go to the pages listed next to the product. The nuts and bolts of this book is what goes into my winter programming and our updated Extension Bulletin 237.

Extension Bulletin 237

Extension Bulletin 237 is printed and is being bound this week. We should have it for distribution by the first of the year. We've made a number of important changes to EB 237 that should help you and your clientele in making decisions about what product(s) to use Let me outline some of the changes.

-Guide to prepacked mixes - completely updated. Let's the reader know what is contained in a package-mix product.

-Guide to single active ingredient herbicides - completely updated. Gives the reader the trade name, common name, mode of action and manufacturer.

-Rain-free requirements following application of postemergence herbicides - includes all postemergence herbicides and how much time you have to wait between application and rain. I use this quite a bit when rain is threatening.

-Herbicides and their restrictions - We've added this for both the corn and soybean herbicide sections. It lists whether the herbicides are restricted use, lists a water quality advisory if the product has one and also lists the worker reentry interval. This is extremely useful for people that need to get back on land after a herbicide application has been made.

-Relative effectiveness of herbicides - for both the corn and soybean sections we've expanded the list of weeds and have added an excellent rating (>90%) to separate products better.

-Grazing and feeding restrictions - has been updated for corn, forages and soybeans. This is always extremely helpful in dry years like we had in 1999. Some growers wanted to feed soybean hay and this table allowed you to see if the product(s) used were OK for use.

-Herbicide rotational restrictions - completely updated for corn, soybeans and vegetables. Don't forget, the last table in the weed control section lists vegetable herbicide rotational restrictions. With more and more produce being grown, this table is extremely helpful.

-Approved tank-mixes - We've included and updated four very useful tables in the corn and soybean sections. They are as follows: 1. Approved tank-mixes for soil-applied herbicides in corn, 2. Approved tank-mixes for foliar-applied herbicides in corn, 3. Approved tank-mixes for soil-applied herbicides in soybeans, and 4. Identifying tank-mix partners for postemergence weed control in soybeans. These tables are very useful in deciding which products and be legally tank-mixed together.

-Postemergence overtop broadleaf herbicide rate chart and the application rates and grass sizes charts for soybeans - extremely useful in deciding what products work best for a specific weed and what rate to use. I use these tables a lot!

-As usual, we've also added a number of new products throughout the text. It's a great reference material, so we hope you utilize it to its fullest extent!

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Changes

Let me cover some of the changes that are happening this winter. First of all, most of you have probably heard that the agricultural divisions of Zeneca and Novartis are merging to form a new company called Syngenta. We won't know the full impact of this until the middle of the year 2000. It's been noted that 3,000 people will be let go.

American Cyanamid is changing the IMI nomenclature to the term known as the Clearfield Production System. Thus IR corn or IMI corn will be known as Clearfield corn. By the way, IMI or Clearfield corn is non-GMO.

Backdraft = Scepter + Roundup

Extreme = Pursuit + Roundup

Their intent with these products is for use on Roundup-Ready soybeans with the opportunity to provide residual control of weeds later in the season

BASF is introducing a product called Celebrity Plus. It's a package-mix of Accent plus Distinct. Their suggested use rate is 4.8 oz/acre. With this rate you get 4 oz/acre of Distinct plus 2/3 oz/acre of Accent. This product will be very useful in cleaning up corn ground where both grass and broadleaf weeds escape control.

Dow AgroSciences will be handling their own line of glyphosate (Roundup) products. They are as follows:

Glyphomax = Roundup

Glyphomax Plus = Roundup Ultra

Dow will be pushing a program called the BestShot Program. Here, they want you to mix their FirstRate herbicide with their glyphosate product line for use on Roundup-Ready soybeans.

Dow will also be handling pendimethalin (Prowl) under the trade name Pendimax.

Monsanto intends to introduce a new product for Roundup-Ready corn called Ready Master ATZ. It's a mixture of Roundup Ultra plus atrazine. Monsanto also has a new formulation of acetochlor (Harness) called Degree Xtra. Apparently, it's a soil activated temperature formulation of acetochlor plus atrazine. As the soil temperatures warm up, the product becomes available for plant uptake. Under cold conditions, it remains unavailable.

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At this point in time, Monsanto has licensing agreements with the following companies to sell glyphosate:

Terra will be introducing a new product called Sterling which is a package-mix of atrazine plus dicamba (Banvel).

GMO or GEO

What's genetically modified or enhanced and what's not.

Dicamba Products and Volatility

There are a number of dicamba products in the marketplace. Every year I get questions about their volatility. The following table should help.

Happy holidays!

Ronald L. Ritter

Extension Weed Control Specialist

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