Working together to strengthen and support noxious weed management efforts in Montana.

Integrated Weed Management

New Expanded Why Should You Care? Available Now

Friday, August 1st, 2014


MWCA is thrilled to announce their newest publication.   It is the completely updated and expanded Why Should You Care? booklet.    Now not only does this booklet cover the topic why should people care about noxious weeds, but it has been expanded to include information on integrated weed management, weed identification, a list of all weed districts in the state of Montana but also what actions people should take with the noxious weeds they find.

Why Should You Care?

Why Should You Care?

We have single issues available in our store and case pricing to the store.  Remember members receive great discounts on their purchases.  If you are not a member, purchase it at the same time as your other purchase and immediately qualify for member rates.   Visit our online store for all our publications and products.

This is great inexpensive way to provide educational material to your customer and public.

We have provided a sample version of the brochure for your inspection.   Download the sample Why Should I Care? 3mb.

Results of Weed Mgmt and Research Needs Survey

Tuesday, May 14th, 2013


The Integrated Weed Management (IWM) committee of the Montana Weed Control Association (MWCA) recently conducted a survey of weed professionals. The survey was part of the IWM’s “Building Bridges” goal of facilitating communication between researchers and managers. We hope the following results bridge on-the-ground weed management needs with current research by: providing direction to research programs in Montana, identifying conference and field tour topics, and updating the Montana Weed Management Plan.

The results summary is available for download.

Thank you to everyone who  participated in the survey.

Monica Pokorny, MWCA IWM Chair

IWM Committee News & Minutes

Tuesday, January 29th, 2013


The most current documents appear at the top.

2008 Minutes

Applying Biological Control Methods For Weed Management – MSU Weed Post

Sunday, December 30th, 2012


Biological control agents are organisms (e.g. insects, nematodes or fungi) that can be used to manage large weed populations. Typically these organisms are natural enemies of the target species in their native continent and are introduced to their new range following testing to ensure they do not harm non-target plants. Biocontrol agents have been approved and released for several weed species in Montana. Download the complete post to find out the ins and outs of biocontrol from beginning to end.

This publication is produced by Montana State University Extension and the Montana Noxious Weed Education Campaign

Learn About Calibration for Using Herbicides

Thursday, August 19th, 2010


One of the most important things that can be done when using herbicides is making sure you are spraying the right plant and you are using the right amount of herbicide.  Learning how to use the right amount of herbicide is called calibration.

There are many ways a person can learn about calibration.

  • Contact your local weed coordinator or extension agent.
  • Attend a Private Applicator’s Class in your area.
  • Use a combination of print and video materials available.

The following are some of the print materials available.  We have provided links or you may contact your extension agent.

MWCA helped to underwrite this short video that demonstrates calibration of equipment.  We have broken it down in to 6 steps.

Chapter 1 Importance of Calibration

Chapter 2 Equipment & Pre-Calibration Check

Chapter 3 Understanding Calibration

Chapter 4 Calibrating Backpack Sprayer and Handline

Chapter 5 Calibrating Using the Strip Method

Chapter 6 Adding Pesticide to Your Tank

MSU Extension also has a DVD available for purchase on their website. There is also information on the MSU Webpage on Calibration.

Compatibility of Seed Head Biological Control Agents and Mowing for Management of Spotted Knapweed

Monday, April 5th, 2010


Authors: Jim M. Story, Janelle G. Corn, and Linda J. White

Summary: Seed head insects, primarily the seed head fly, Urophora affinis, and the seed head weevils, Larinus spp., are reducing spotted knapweed seed production by about 94% in most areas of western Montana. Studies were conducted on the compatibility of seed head biological control agents and mowing for management of spotted knapweed.  Our study demonstrated that mowing of spotted knapweed in the spring and early summer can result in the growth of secondary flower buds which escape attack by seed head biocontrol agents, thereby allowing the knapweed to produce a nearly-normal complement of seed.  Therefore, we conclude that the historical practice of mowing spotted knapweed during the spring and early summer with no follow-up mowings should be avoided if large populations of seed head biocontrol agents are present.

Download a copy of the research article.

Influence of Seed Head-Attacking Biological Control Agents on Spotted Knapweed

Wednesday, March 24th, 2010


Complete Title: Influence of Seed Head-attacking Biological Control Agents on Spotted Knapweed Reproductive Potential in Western Montana over a 30-year Period

Authors: Jim M. Story, Lincoln Smith, Janelle G. Corn & Linda J. White

Summary:  Studies were conducted on the impact of seed head insects on spotted knapweed reproductive potential in western Montana over a 30-year period.  Results indicated that seed head insects are reducing seed production by about 94% in many areas of western Montana.  The reduction of knapweed seed production has resulted in a 98% reduction in the knapweed seed bank which, in turn, has contributed to the decline of knapweed in these areas.  Of the seed head insects, the fly, Urophora affinis, and the weevils, Larinus obtusus and L. minutus, are having the greatest impact on knapweed seed production.  The current decline of spotted knapweed in many areas is likely due to the impact of the seed head insects on the knapweed seed bank and the effects of the root weevil, Cyphocleonus achates, on mature plants.

Download a copy of the research article.

Decline of Spotted Knapweed Density in Montana with Large Populations of the Root Weevil

Monday, March 15th, 2010


Full Article Name: Decline of spotted knapweed density at two sites in western Montana with large populations of the introduced root weevil, Cyphocleonus achates (Fahraeus)

Authors: J.M. Story, N.W. Callan, J.G. Corn, L.J. White

Summary:  Spotted knapweed plant density was monitored over a 11-year period (1993-2004) at two sites in western Montana where the root weevil, Cyphocleonus achates was released.  Spotted knapweed density declined significantly over time at both sites (99% and 77%, respectively), after C. achates numbers increased dramatically at both sites.  The current decline of spotted knapweed in many areas is likely due to the effects of C. achates on mature knapweed plants and the impact of the seed head insects on the knapweed seed bank.

Click here to download and read the complete article.

Turning Livestock into Land Management Tools at Grant-Kohrs Ranch National Historic Site

Sunday, November 29th, 2009


by Christina Miller,
Natural Resources Specialist, DSC Socks, Spackle, and Ginger Snap are only a few of the newest weed control managers at Grant-Kohrs Ranch NHS. They successfully completed a seven-step program that modified their preferred cuisine and made them effective rangeland stewards. These new weed control managers dutifully spend their days grazing in the pastures, working toward the eradication of exotic invasive weeds. Oh, by the way, they’re cattle, affectionately termed “smart cows.”

Read the complete article about these weed eating cattle.