1. Sauk-Suiattle Indian Tribe 2013 Knotweed Eradication Efforts
Andrew W. McDonnell
Natural Resources Field Coordinator
Sauk-Suiattle Indian Tribe

3. Clusters of knotweed at the watershed level.
Darrington: People
Prairie: Machinery
Middle Sauk: Not so much knotweed…Pretty swift.
Lower Sauk: Fans out, a lot of sidechannel and backwater habitats. This slows down the transport of water, sediment, and it turns out, knotweed.

5. 2013 – 13.28 gallons concentrated glyphosate
Herbicide – Imazapyr 1%
118 gallons in solution
1.18 gallons concentrated
2011
Herbicide – Imazapyr 1%
470 gallons in solution
4.70 gallons concentrated
2012
2013
Herbicide – Imazapyr 1%
298 gallons in solution
2.98 gallons concentrated
As we visit more historical patches, and discover new ones, we tend to spray more herbicide to control the spread.
Read off.
Sprayed less Imazapyr this year despite visiting more patches than in 2012.
Patch sizes are reducing!
2013 – gallons concentrated glyphosate

7. 7%
40%
33%
17% 3%

9. 2 yrs of treatments
Two years of consecutive treatments resulted in 71% of new patches identified in 2011 to be dead.

10. 2 yrs of treatments 1 yrs of treatments
Next add 85% +- 7% reduction in size.
Fix: Remove Red Bar.

12. 2012 Field Season 2013 Field Season Priority Areas for 2013.
Status following 2012 treatments
Status as of 2013 (Effectiveness of those treatments)

13. 4 acres

14. 4 acres How did we treat this? Took about a day to bend
Treated with Imazapyr and glyphosate
3 days of treatments
Interesting observation: knotweed seemed to be growing mostly in and around old stumps, so it actually made paths for us to navigate though while spraying.

15. Snohomish County Noxious Weed Control Board
Wild & Scenic River Tours