The mission of this program is to evaluate weed management practices to help Wisconsin growers sustainably control weeds and maximize the production of corn, soybean, small grains, and sweet corn crops. Through integration of applied field research and extension activities, we strive to deliver thorough, unbiased results to Wisconsin crop producers and improve upon the body of scientific weed science literature.

To read the complete blog, please visit the Out of Control page.

Cover Crop Field Day

The Wisconsin Crop Weed Science program will be at the NEW Cover Crop Field Day on October 8, 2014 at the Arlington Agricultural Research Station. An array of cover crop topics will be covered by University of Wisconsin-Extension faculty and staff and the research director of the Michael Fields Agricultural Institute. For registration information and the agenda, please visit UWEX’s Cover Crop Workgroup site.

Winners Announced from the Biggest Weed Contest


The Department of Agronomy’s Mark Renz announces this year’s winners of the Biggest Weed Contest at the Farm Technology Days, August 12-14, 2014.

2014 Contest Winner

This giant ragweed, submitted by Ken McGwin of Montello, was the Day 1 winner of the Biggest Weed contest at Wisconsin Farm Technology Days. Measuring 12’6” x 4’, its overall size wasn’t big enough though to beat the grand champion – another giant ragweed measuring over 10 feet tall and seven feet wide.

Here is Mark’s press release:

Contact: Mark Renz, UW-Extension weed specialist, 608-263-7437, mrenz@wisc.edu

Biggest Weed contest winners announced

Madison, Wis. – Despite the cool summer, plenty of weeds were entered in the ‘Biggest Weed’ contest sponsored by University of Wisconsin-Extension/Madison Weed Experts at the recent Wisconsin Farm Technology Days. Of the many samples brought in for identification, eight participants submitted nine weeds they felt deserved the title of Biggest Weed.

“While none of the samples topped the 13 foot mark like last year, several were quite wide, making up for the lack of height,” said Mark Renz, University of Wisconsin-Extension/Madison weed specialist. “Of the nine samples submitted, four were annuals, four biennials, and only one perennial plant – common milkweed.”

Typically the biennial and perennial plants take the prize, but this year a giant ragweed was the grand champion. Wayne Greeler from Neillsville, Wisconsin brought in this specimen that was over 10 feet tall and seven feet wide. The overall size of the plant is determined by multiplying the weed’s height by the maximum width when held in its normal growth form.

Renz said, “It is uncommon for a giant ragweed to get this wide but the extra girth allowed it to take the grand prize.”

Tuesday’s winner was another giant ragweed submitted by Ken McGwin from Montello. It was much taller than the grand champion, more than 12 feet, but only four feet wide. Wednesday’s winner Mary Jane Fry from Pittsville did bring in a massive bull thistle, but its dimensions couldn’t match the winners from Tuesday or Thursday.

“All submissions were found next to a barn, shed, fence, or tree,” Renz noted, “So apparently having a structure nearby helps. Remember this tip when we hold the event next year at Wisconsin Farm Technology Days in Dane County.”

All daily winners will receive a weed identification book, as thanks for hauling these winning specimens to Wisconsin Farm Technology Days. Anyone who has tried to bring in one of these plants can attest that it is no easy task.

For more information about identifying and controlling weeds in your field or yard, contact your local county Extension agent or visit the University of Wisconsin Weed Science website at http://fyi.uwex.edu/weedsci


Funding available from Buy Local, Buy Wisconsin

The Wisconsin Department of Agriculture, Trade and Consumer Protection manages the Buy Local, Buy Wisconsin grant program for farmers and other members of the food industry who want to develop local markets for their products.

For more information, please visit the Buy Local, Buy Wisconsin website

Next Week: Agronomy and Soils Field Day

Don’t miss the 2014 Agronomy and Soils Field Day next week!

On Wednesday, August 27th, the Arlington Agricultural Research Station will host the Agronomy/Soils Field Day from 8:00am-3:00pm. Join us on four separate tours throughout the day as UW-Extension and Agronomists share current research developments in grains, soils, forages, and greenhouse gases. Presenters include: Vince Davis, Bryan Jensen, Joe Lauer, Matt Ruark, Randy Jackson, Francisco Arriaga, Erin Silva, Gregg Sanford, Dan Undersander, Mark Renz, and Damon Smith. During lunch, enjoy exhibits such as: UAV aerial photography, Apps for Ag, Nutrient and Pest Management Programs, Integrated Pest Management Program, SnapPlus, and more. Agronomy/Soils Field Day is open to the public, does not require registration, and will be held rain or shine.

Click here for the official event flyer.

Author: Steven Gruber

Steven Gruber will be a junior in the fall at the University of Wisconsin-Madison pursuing his undergraduate degree in Microbiology through the College of Agriculture and Life Sciences. This summer, he is currently an undergraduate research assistant for the Agronomy-Weed Science department and hopes to further his research experience in plant-microbe interactions.

USDA New Farmer Program

The USDA has created a program for people who wish to begin farming. They have put together a website with many helpful resources for anyone who is starting out in the industry. The video attached below demonstrates what the website has to offer including how to find a USDA Service Center near you.

Here is a link to their website:


Author: Jessica Taylor

Jessica Taylor is working as an undergraduate research assistant for WCWS at the Arlington Agricultural Research Station for the summer. She is currently studying Agri-Business and Ag Production at Northeastern Junior College in Sterling, CO. After she completes her sophomore year, she is planning on transferring to a four-year college and completing her degree in Agriculture Education.

To-Do List: Fall Dandelion Management


It’s time to start planning ahead for fall dandelion management. The Weed Science website at the University of Wisconsin Extension has a thorough description of the dandelion’s life cycle and some suggestions for control. A group of researchers at the University of Wisconsin evaluated fall and spring herbicide applications for control of dandelion in 2011. Their key findings were:

  1. Herbicide applications in the fall were most effective for early-season dandelion control compared to applications at normal corn planting in the spring.
  2. Applications during the spring were ideal for late-season control when soybean planting occurs.

For specific information on herbicides, please see their slide presentation.

The flowering stage of dandelion is easily identified by most. However, identifying the seedling stage is helpful because management is best before dandelions enter the adult stage. The following plant characteristics will help with identifying seedling dandelions:

  • Seed leaves (cotyledons) are oval or spoon-shaped
  • First true leaf is ovular and 0.4 inches (1 cm) long. Leaf margins have a few very small teeth that point back toward the base of the leaf. The midvein is prominent on the underside of the leaf.
  • Later leaves are more elongated and will have the toothed margins and rosette arrangement typical of the mature plant.

Managing dandelions can either be done through the use of herbicide or physical removal in either the spring or fall. However, dandelions are more susceptible to herbicides applied in the fall. If physical removal is the management mode of choice, it must be done in the spring as well as the fall.

Management options for corn and soybean are listed below.


Chemical control options:

  • Fall application of 2,4-D or dicamba at 1 pint per acre applied alone or as a tank mix prior to the first killing frost. Another option is glyphosate but for optimal activity applications need to be made when the air temperature is above 50 degrees F and the plant is still actively growing.
  • Spring applications of 2,4-D ester at 1 pint per acre prior to corn emergence or a tank-mix of 2,4-D with glyphosate will provide some dandelion control. Also, post-emergence applications of growth regulator herbicides typically provide acceptable control.

Mechanical control options:

  • Moldboard or chisel plowing will weaken the plant by disturbing the taproot and may make chemical applications more effective.


Chemical control options:

  • 2,4-D ester may be applied prior to soybeam planting if a seven-day interval is observed between application and planting.
  • There are no good post-emergence options for dandelion control in soybeans.
  • If possible, control heavy infestations of dandelions in the fall if the field is to be planted to no-till soybeans.


  1. http://www.extension.psu.edu/pests/weeds/weed-id/common-dandelion, site accessed July 27, 2014.
  2. http://www.umanitoba.ca/outreach/naturalagriculture/articles/dandelion.html, site accessed July 27, 2014.
  3. http://fyi.uwex.edu/weedsci/2002/11/12/dandelion/, site accessed July 27, 2014.


Madeline Fischer and Liz Bosak

Madeline Fischer is an undergraduate research assistant working for WCWS at the Arlington Agricultural Research Station. In Fall 2014, Madeline will be a sophmore pursuing a degree in Life Science Communcations and Environmental Studies.