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The Global Invasive Species Team | |
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Global Invasive Species Team listserve digest #033 Tue, 8 Jun 1999 18:40:33 -0700 (PDT) --CONTENTS-- 1. Herbicide dilutions: % and a.i. 2. Weed job in Flagstaff, AZ 3. New Bromus tectorum Species Management Summary 4. Pack-horse spray rig 5. Phragmites population genetics --------------------------------------- 1. Herbicide dilutions: % and a.i. From: Jim Welsh (jwelsh(at)tnc.org) Regarding setting concentrations in backpack sprayers, I believe that in the past I may have misunderstood label instructions to mean percent active ingredient when in fact the label mixing instructions may be intended to give a desired volume of the bottled solution. Say, for example, that I want to spray 2% active ingredient Roundup Ultra (which is delivered in the jug at 41% active ingredient). The label mixing instructions are written for the desired volume of spray solution, not the active ingredient. According to the label mixing instructions, using 2-2/3 oz Roundup Ultra in 1 gallon of water gives a 2% spray solution. The active ingredient in this mix is actually ~0.8%, not 2%. To get a 2% active ingredient spray solution in one gallon of water, you would have to mix ~6.5 oz of Roundup Ultra in 1 gallon of water. ----Jim is correct. When preparing a tank mix, always mix to the correct dilution. If you are told to mix the solution to (for example) 2%, mix 1 part herbicide with 49 parts carrier. You only have to worry about the percent Active Ingredient if the desired concentration is specifically written for some percent A.I.----Barry --------------------------------------- 2. Weed job in Flagstaff, AZ From: Edward Smith (ebsmith(at)flagstaff.az.us) Weed Management Area Coordinator Needed (1/2 time Botanist, GS-0430-09, $16,513/yr) The Supervisor's office (Flagstaff) of the Coconino National Forest is seeking someone to fill a new job that resulted from our receipt of a NFWF grant for work with the Northern Arizona Weed Council (NAWC). The incumbent will work 1/2 time and is "responsible for designing, developing and executing the San Francisco Peaks Weed Management Area (WMA) noxious weed program..." For a more detailed description and application, please see the USDA jobs web page (below). Application must be postmarked by 6/11/99. Please disperse the word like knapweed, far, wide, and to fertile yet disturbed soil! For more information, please contact Barb Phillips at 520.527-3421. http://www.usajobs.opm.gov/a9ag.htm --------------------------------------- 3. New Bromus tectorum Species Management Summary From: Barry Rice (bamrice(at)ucdavis.edu) Tomorrow I will upload a new Cheatgrass (Bromus tectorum) Element Stewardship Abstract to the Invasives on the Web site (http://tncweeds.ucdavis.edu). Species Management Summaries of other new species will be available soon, too. --------------------------------------- 4. Pack-horse spray rig From: Jil Swearingen (JIL_SWEARINGEN(at)nps.gov) Jil sent us an article first published in a May 1999 publication produced by the USDA Forest service. I include it below in edited form. FOREST DEVELOPS NEW SPRAYER FOR REMOTE WEED TREATMENTS The White River National Forest in Meeker, CO has developed a specialized weed sprayer....designed to be mounted on a packhorse. The [Saddlelight] operator is horseback, and leads the pack animal carrying the sprayer. In most cases the rider can treat small patches and keep moving, without ever getting off his horse. Approximately 50 of these units have been constructed and are being marketed by the White River Soil Conservation District, at a cost of $450 [each]. The Saddlelight utilizes a lightweight aluminum pannier system which holds four 5-gallon beverage cans. The herbicide mixture is placed into the cans and is despensed with the use of CO2. The beverage canisters are ideal because they are made of non-corrosive stainless steel. They are strong, lightweight, leak-proof and pressure tight. The five pound CO2 bottle that comes with the unit is capable of dispensing about 70 to 80 gallons of liquid mix before needing to be recharged. Although the system is mostly noiseless, gentle horses and good horsemanship skills are needed for safe operation. If you have a large number of remote weeds...this is an excellent tool to consider for efficient weed management. For more information, contact Tom McClure (CO) or Hal Pearce (CO) at 970-878-4039, --------------------------------------- 5. Phragmites population genetics From: John Randall (jarandall(at)ucdavis.edu) Pellegrin, D. and D.P. Hauber. 1999. Isozyme variation among populations of the clonal species, Phragmites australis (Cav.) Trin. ex Steudel. Aquatic Botany 63: 241-259. Copies available from the weed program. The authors examined isozyme variation of 37 populations of Phragmites from 12 states along the Gulf coast, East coast and upper midwest. Unfortunately they had no samples from the East between VA and NY. Preliminary work found little or no variation within populations suggesting that most individual populations are from a single clone (genet). Twenty one populations were sampled from the Gulf coast from Texas to the Florida panhandle and all but two were uniform. Two populations from the Mississippi Delta in LA were distinctive and behave invasively. Populations along the east coast differed but were more similar to each other than to other populations. The same was true for populations from the upper midwest. A population invading a CT wetland was not distinctive from other east coast popuations and did not resemble the invasive Mississippi Delta populations. Except for the Mississippi Delta populations the authors suggest these data don't support the hypothesis of an exotic invasive gentoype ('biotype') of Phragmites. However, they note that studies combining history of particular wetlands and population genetics of Phrag in them, plus common garden studies could better unravel human influence on Phrag invasivess. |
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