Authors - Kim Goodwin, Project Specialist Roger Sheley, Associate Professor

1. Rangeland Weed Management Authors - Kim Goodwin, Project Specialist Roger Sheley, Associate Professor Janet Clark, Director, Center for Invasive Plant Management Department Editor - James E. Knight, Extension Agriculture and Natural Resources Program Montana State University

2. Part 2 • This is the second half of the weeds PowerPoint presentation

3. Integrated Weed Management • Develop & maintain healthy, desired plant communities • Variety of preventive strategies • Large versus small weed infestations

4. Prevention & early detection • Prevention – most effective, least costly • Limit weed dispersal • Detect and eradicate early • Re-vegetate when necessary • Properly manage desired plants

5. Limiting dispersal of weed seeds • Certified weed-free gravel, seed mixes, forage, and mulch • Clean undercarriage of vehicles • Boots and clothing • Livestock movement • Detect early – pull, clip, bag, burn • Eradicate

6. Detecting & Eradicating Weed Introductions Early on • Monitoring is crucial • Develop a Monitoring plan • Spring • Summer • Early Fall

7. Eradicating small seed patches • Newly established • Small than 100 square feet • Prioritize: low-density responds more quickly • Document changes in patch size & density • Flag or mark • Frequent follow-up

8. Managing Large Infestations • Limit seed dispersal • Requires use of many management methods • Mechanical • Chemical • Cultural, and • Biological

9. Large Infestations, cont. • Mowing effectiveness based upon: • Time of growing season • Biological characteristics of the target weed

10. Large Infestations, cont. • Chemical control - herbicides • Eradicate • Reduce weed vigor • Long-term control – when healthy plant community is present

11. Selecting the right herbicide • The target weed • Weed density • Herbicide toxicity • Herbicide degradation time • Desired vegetation cover • Soil attributes • Proximity to water, and • Environmental conditions.

12. Time herbicide application • Nonresidual herbicides: • During seeding/rosette, • Early bud, and • Fall regrowth • Soil-residual herbicides: • Timing is less important

13. Suggested Placement • Depends upon the size of the infestation • Moderate size – wide treatment • Large size – perimeter treatment

14. Cultural Control • Promote growth & competitiveness of desired plants • Re-vegetation • Management of desired plants • Grazing Management

15. “Single-entry” Revegetation • One late-fall field entry • Cost-effective • Yields reliable revegetation

16. Cultural Control • Grazing • Domestic sheep • Early bud stage of the weed • Weaken the weeds • Over time – effects underground reserves • Eventually reducing stem densities

17. Biological Control • Insect biocontrols • Remove viable fluids • Defoliate • Eat seeds • Bore into roots, shoots, and stems • Effective when integrated with other management strategies

18. Monitoring & evaluation • Periodic observation is necessary • Does not need to be elaborate • Photo monitoring

19. Integrated Weed Management Plan • Following a burn – weeds are likely • Is revegetation necessary? • Fall-dormant broadcast reseeding effort