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News.bytes Extra, issue 500 


 Aerial Spraying of Tamarisk

Helicopter spraying herbicide over tamarisk in Fresno County  


The Bureau of Land Management has taken to the air in an effort to control invasive shrubs.

Approximately 350 acres of tamarisk in western Fresno County was sprayed this month with imazapyr (Habitat) and glyphosate (Aquamaster) by helicopter.

Helicopters remove the barriers associated with travel over uneven terrain (vs. ground vehicles) and allows for relatively targeted herbicide application (vs. fixed wing aircraft), said Ryan O'Dell, natural resource specialist in BLM’s Hollister Field Office.  The effects of the aerial herbicide application treatment will be monitored and treatment with the same method will continue in following years if the results are satisfactory.

Aerial herbicide application to tamarisk by helicopter has successfully been used to control tamarisk on BLM land in New Mexico and Colorado, but this project marks the first time that aerial herbicide application has been conducted on BLM land in California, according to Dianna Brink, BLM California State Office Range and Weed Program lead.

Tamarisk is a noxious, invasive woody shrub that has invaded riparian zones throughout arid regions of the western United States, including Panoche Creek and Silver Creek on BLM Hollister Field Office managed-land in western Fresno County. Tamarisk has displaced native woody riparian vegetation, reducing habitat quality for native plant and animal species and altering riparian zone hydrologic function.

Previous tamarisk control methods at Panoche Creek and Silver Creek have included brush mowing and cut stump application of glyphosate in 2006, basal bark application of triclopyr to re-sprouted plants using backpack sprayers in 2007 and 2008, and foliar application of glyphosate with a boom attached at an elevated position on a small Caterpillar in 2010.  All of these ground-level treatments have proven unfeasible at large scales due to uneven terrain and the operational limits of ground vehicles.  None of the treatment methods have significantly reduced the tamarisk within the project area.

-David Christy, BLM CCD Public Affairs, Mother Lode Field Office, 9-28-11

BLM-California News.bytes, issue 500 -- To subscribe to News.bytes, send an e-mail to: mailto:Join-Newsbytes@List.ca.blm.gov OR visit our News.bytes subscription page .

Last updated: 10-07-2011