Des Moines, Iowa
May 14, 2002

Dry soil in some areas and non-stop rain in others means corn growers may want to look into post-emergent herbicides as a weed control option this season. That's the recommendation from agricultural specialists with Pioneer Hi-Bred International, Inc., who suggest keeping a close eye on fields due to the varying weather and soil conditions.

"It's been dry in parts of the country, and that means, in some cases, herbicides applied before planting might not take," says Joe Mayer, a Pioneer agronomist based in Pennsylvania. "A good post-emergent herbicide applied early can help tackle the weeds that were unaffected by a pre-emergent treatment." "Weed control is always important, but this year, it's even more important because of the dry conditions," says Dan Berning, a Pioneer agronomist in Nebraska. "You want to get out there early and eliminate the weeds that are competing for the same moisture as your corn."

While dry weather is one reason to look at post-emergent herbicides, the wet rainy weather that's hampered planting over the last few weeks is another. "With the prime corn planting time slipping away due to wetter weather, it may make sense for some growers to switch herbicide plans from a
pre-emergence strategy to an early post-emergence strategy that offers the necessary contact and residual control," says Mayer. "Plus, by applying after planting, you don't have to guess which weeds will be a problem this year."

The key to good post-emergent control is not to wait until the weeds are tall and out of control. Rather, be ready to go within three weeks of planting. If corn was planted between May 1 and May 10, fields should be ready for a post-emergent application near the end of the month when the corn is three to four inches tall.

According to Berning and Mayer, a dependable post-emergent weed control program should include the following:

• Good control of the toughest grasses and broadleaf weeds, including foxtail species, wooly cupgrass, fall panicum, wild proso millet and field sandbur.
• Good contact control independent of rain plus season-long residual control with an activating rainfall.
• A wide window of application relative to corn growth so there is ample time to protect the crop from later-emerging yield-robbing grasses.
• Tank mix flexibility to provide opportunity for broad-spectrum broadleaf control.
• A company representative who is readily available to help identify weed challenges, answer questions and assist with application if needed.

Ag retailers offer a number of herbicide options to growers, including DuPont SteadfastTM, Accent Gold(R) and Basis Gold(R). Contact your local DuPont retailer to find out which herbicide program best meets your needs. Always read and follow label directions carefully.

Pioneer Hi-Bred International, Inc., a subsidiary of DuPont, is the world's leading source of customized solutions for farmers, livestock producers and grain and oilseed processors. With headquarters in Des Moines, Iowa, Pioneer provides access to advanced plant genetics, crop protection solutions and quality crop systems to customers in nearly 70 countries. During 2002, DuPont is celebrating its 200th year of scientific achievement and innovation - providing products and services that improve the lives of people everywhere. Based in Wilmington, Del., DuPont delivers science-based solutions for markets that make a difference in people's lives in the areas of food and nutrition, health care, apparel, home and construction, electronics and transportation.

SteadfastTM, Accent Gold(R) and Basis Gold(R) are trademarks or registered trademarks of E.I. du Pont de Nemours and Company.