Farmers Face Glyphosate Price Hike

ISU weed management specialist cautions against applying less than recommended rates of the herbicide.

Fuel and fertilizer price increases are being joined by rising prices for glyphosate herbicide in 2008. After years of price declines for the widely-used weed control product, farmers are facing sticker shock as suppliers struggle to keep up with strong demand. Prices for generic glyphosate have doubled since last year and Monsanto-branded Roundup has jumped 30% in price.

Jim Zimmer, Monsanto vice president for U.S. brands, says the company has been forced to raise prices at unprecedented rates due to market dynamics. "Over the past year on a global basis, glyphosate demand has increased significantly - to the point where demand is increasing faster than supply." In particular, he adds, South America has emerged as a strong market for glyphosate products.

Another factor is most manufacturers of generic glyphosate haven't increased their production. About 30 companies worldwide make glyphosate, and many of them are in China. Energy shortages created by China's booming economy have caused some plants to shut down periodically, while others are being shut down for periods of time as Chinese officials want to make sure the plants conform to pollution control regulations. The Chinese government is stepping in and putting environmental regulations on manufacturers.

Don't cut glyphosate application rates

The worst thing farmers can do in reaction to the glyphosate price hike is to cut application rates of the herbicide. "By applying less than the recommended rate of glyphosate per acre, you run the risk of not getting satisfactory weed control," cautions Mike Owen, an Iowa State University Extension weed scientist.

The old adage of "Penny wise and pound foolish" comes to mind. With the widespread and continuous use of glyphosate on more acres of corn and soybeans in recent years, there are some weeds that are becoming increasingly difficult to control. Those include common lambsquarters, common waterhemp and giant ragweed. Trying to get by with reduced application rates of glyphosate may speed up the shift in weed populations and result in more escaped weeds.

For farmers who are having a problem with a weed species that is not responding to glyphosate, ISU Weed Science Extension is getting ready to introduce a program this spring that will encourage those growers to further investigate the problems by contacting ISU Weed Science Extension. "We want to take a harder look at the situation this year, to see if glyphosate resistance in weed populations is occurring in Iowa fields," explains Owen. "We will be announcing a program in detail about this in a few of weeks."

Watch for new Extension weed program

Basically, the program will work like this. If you are having problems with a weed not being controlled by glyphosate, you can let the ISU specialists know and they can come out and investigate. Owen says probably 99 times out of 100 there are other issues involved and it's not weed resistance that is causing the escapes. For example, the ISU specialists can help you determine some useful information to zero in on the real cause. For example, was the herbicide applied at the right rate per acre and applied at the right time?

"That's the first thing we'll do when we investigate," says Owen. "We'll ask these types of questions. If we determine that the glyphosate was applied appropriately then we'll go into the field and collect some weed seed and plant them in our growth chamber and greenhouse and assess the response to glyphosate. We may look at the heritability of the resistant trait, if specific populations meet our criteria and ultimately we will seek the cooperation of the grower and request permission to go back to the fields in question the following year and run a small glyphosate application rate comparison."

"Many times the things that happen with weeds when we grow them in a growth chamber or greenhouse aren't exactly what we see going on in the real world out in the farmer's field," says Owen. "So we have to double check that when we do this testing. The specific details for this new ISU Extension weed management program are under development now, and when they are finalized, we'll publicize the information and explain how you can take part in the program."

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