The Enid News and Eagle, Enid, OK

Ag

December 1, 2012

You need to know herbicide’s mode of action

ENID, Okla. — There are a large number of herbicide options available to crop producers, gardeners and landscapers.

We have new products, old products with new names, and new formulations of old products, premixes and now generics. Can protecting your desired plants from weeds get any more complicated? Yes it can.

You will need to know the plants a product can be used with, and now, will the product you choose damage the weed causing you problems without hurting the desired plants that are growing? It will be more important to know how the product of choice will harm the weed of choice. This means you need to know the “mode of action” of the herbicide.

The mode of action of an herbicide is the way in which the herbicide controls the susceptible plants within a field or landscape. It usually describes the biological process or enzyme in the plant the herbicide interrupts, affecting normal growth and development. The mode of action also might be a general description of the injury symptoms seen on a susceptible plant.

In Oklahoma, there are 11 modes of action commonly used. There are more, but the others seldom are used in our state. Each is unique in the way it works on susceptible plants. Some modes of action comprise several chemical families that vary slightly in their chemical composition but cause similar injuries to susceptible plants.

Knowing and understanding each herbicide’s mode of action is an important step in selecting the proper herbicide and designing a successful weed management program. Right now, our over-reliance on a single herbicide mode of action is placing heavy selection for resistant weeds. Over time, resistant weeds multiply and become the dominate weed in the field or landscape, resulting in herbicides that are no longer effective. Rotating herbicide modes of action, along with other weed control practices, will prevent or delay the development of these resistant individuals.

Information regarding each herbicides mode of action can be found on the herbicide label. Often times, you will see an herbicide being a member of a particular numbered group. These numbers refer to a specific mode of action and were developed to consistently organize herbicides based on their mode of action.

For example, “Group 1” herbicides are ACCase inhibitors. “Group 2” is ALS inhibiting herbicides and so on.

In some situations, herbicides may not be listing their mode of action. If this is the case, contact your county extension educator for clarification. He or she will direct you to Extension Fact Sheet PPS-2778, “Understand-ing Herbicide Mode of Action.”

This fact sheet will list the group number, chemical family and trade names for almost all of our commonly used herbicides. Most importantly, the fact sheet lists the active ingredient of the herbicide. With the emergence of the generic formulations of herbicides, trade names we have become accustomed to seeing have changed, but their active ingredient name stay consistent. Please get your copy from your Oklahoma Cooperative Extension Service educator soon.

Gribble is Oklahoma Cooperative Extension Service northwest area agronomist.

1
Text Only
Ag
  • farm - Rick Nelson web.jpg Wheat tour to provide crop information

    Damage to wheat from the recent freeze will depend on growth stages and temperatures. It will take approximately seven to 10 days following a freeze to determine damage.

    April 19, 2014 1 Photo

  • FFA logo.jpg Drummond students receive honors

    Several members traveled to Alva for the Northwestern Oklahoma State University Interscholastic Contest.

    April 19, 2014 1 Photo

  • farm - garber ffa web.jpg Garber FFA members place in speech contests

    The Ag 1 quiz bowl team placed fourth and qualified for state. On the second day of the event, the animal science quiz bowl team placed second and qualified for state.

    April 19, 2014 1 Photo

  • Danna Zook cutout web.jpg Producers need to consider cow supplements

    Springtime for many Oklahoma producers often means calving time.

    April 12, 2014 1 Photo

  • Master Gardener logocmyk.jpg It’s time to dirty hands

    Bees are venturing out to visit the new flowers. Keep a close watch on your garden. Often, helpful pest-destroying insects are out, getting ready to work for you, also. These, and the bees helpfully pollinating flowers, shouldn’t be discouraged by the undiscriminating spraying of insecticides.

    April 12, 2014 1 Photo

  • farm - 4H web.jpg 4-H’ers meet with state lawmakers

    Sen. Eddie Fields spoke to the group upon their arrival at the Capitol.

    April 12, 2014 1 Photo

  • Canola tour to have stops in area

    The tour will be held at the canola field of Flying G Farms located 91⁄2 miles west of Orienta on U.S. 412 and then north into the field.

    April 12, 2014

  • farm - Rick Nelson web.jpg Money up front can mean bigger returns later

    Implants are a safe, effective technology that typically offer a 10-to-1 return on investment.

    April 5, 2014 1 Photo

  • FFA logo.jpg 9 area students to receive WLC program scholarships

    FFA members will tour our nation’s capital, visit with members of Congress and perform a service learning project within the Washington area, while building friendships with fellow FFA members from across the nation.

    April 5, 2014 1 Photo

  • FFA logo.jpg NW Oklahoma FFA members named proficiency finalists

    Three finalists are selected in each of 49 agricultural proficiency award categories. The state winner in each area will be announced April 30 during the 88th State FFA Convention held at the Cox Convention Center in Oklahoma City.

    April 5, 2014 1 Photo

Featured Ads
Facebook