* Purdue University Department of Botany and Plant Pathology

June 8, 2007

Purdue Weed Day shows which herbicides pack a punch

WEST LAFAYETTE, Ind. - Some herbicides, like the crops they're protecting, are waiting for rain. At Purdue University's annual Weed Day, farmers and others will see how well - or not so well - the dehydrated weed killers have fared this year.

The free field day takes place 9 a.m. to 5 p.m. June 26. The event begins at Purdue's Agronomy Center for Research and Education (ACRE) near West Lafayette and finishes at Throckmorton-Purdue Agricultural Center and a nearby cropfield south of Lafayette.

About 2,000 plots will be on display where field day visitors can compare the effectiveness of more than 50 herbicides.

Weather conditions usually play a factor in herbicide performance, and this year is no exception, said Tom Bauman and Bill Johnson, Purdue Extension weed scientists and field day coordinators.

"The strength of the field day is being able to see what things work under the conditions that we've had," Bauman said. "This year we've had a really dry spring, so we'll be able to see how the different pre-emerge herbicides work under very dry conditions.

"Some pre-herbicides require a lot of rain to activate and some do not. Some post-emerge herbicides really struggle under dry conditions, as well. So field day visitors will be able to see plots with a range of different efficacies in weed control - some that work very well, some that don't work so well."

At Agronomy Center for Research and Education, plots include corn, soybeans and popcorn. The center is located seven miles northwest of Purdue's West Lafayette campus along U.S. Highway 52.

"We'll start by demonstrating weed control with a number of different herbicide programs in conventional systems and Roundup Ready and Liberty Link systems," Johnson said. "We'll also give an update on our research on glyphosate-resistant marestail, glyphosate-resistant giant ragweed and lambsquarter management."

Around noon the scene shifts to the Throckmorton farm, located about five miles south of Lafayette on U.S. Highway 231.

"We'll have herbicide programs to evaluate lambsquarter, giant ragweed, velvetleaf, giant foxtail control and a number of different tank mix partners that can be used in the Roundup Ready systems," Johnson said. "We'll also have research trials at a site with glyphosate-resistant giant ragweed in a grower's field near Romney."

Lunch will be provided at Throckmorton for those who register before the event. To preregister, contact Bauman at (765) 494-4625 or, or Johnson at (765) 494-4656 or

Certified pesticide applicators attending the field day also are eligible for continuing credit hours.

Additional weed management information is available on the Purdue Weed Science Web site at

Writer: Steve Leer, (765) 494-8415,

Sources: Tom Bauman, (765) 494-4625,

Bill Johnson, (765) 494-4656,

Ag Communications: (765) 494-2722;
Beth Forbes,
Agriculture News Page

Note to Journalists: Other farm-related story ideas are available on Purdue Agriculture's Farming 2007 Web site at

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