Off-target herbicide deposition associated with treating individual trees.
There are a wide variety of different herbicide treatment methods used to remove single trees. Each method (cut-stump, basal, foliar) has a unique amount of off-target disturbance that should be considered in selecting a treatment for use in management. We quantified the amount of off-target deposition that resulted from four conventional herbicide application methods: 1) basal, 2) cut-stump, 3) high-volume, hydraulic foliar, and 4) low-volume, backpack foliar. Basal and cut-stump herbicide treatments deposited up to 200 and 4000 times more herbicide (a.i. per unit area) at groundline than the low-volume and high-volume foliar treatments, respectively. On a per tree basis, basal and cut-stump treatments deposited nearly six times more total herbicide than high-volume foliar, and 68 times more than low-volume foliar. All of the herbicide deposited off-target landed within 0.6 m of the basal and cut-stump treatments, 3.7 m with the low-volume foliar, and 7.3 m with high-volume foliar methods. Off-target herbicide deposition resulted in affected areas with killed or damaged vegetation ranging in size from 0.36 m2 (cut stump) to 7.08 m2 (high-volume foliar). Deposition amounts and affected areas were greater with larger trees, compared to smaller ones. We observed that 48% of the total amount of herbicide applied per plot was deposited off-target with cut-stump treatment, compared to only 4% to 11% for the other treatments. We suspect this difference is due to applicator error with the cut-stump treatment, likely related to the type of spray device used to apply the treatment.
Nowak
Christopher A
CA
Faculty of Forest and Natural Resources Management, State University of New York College of Environmental Science and Forestry, 215 Marshall Hall 1 Forestry Drive, Syracuse, New York 13210, USA. canowak@esf.edu
Ballard
Benjamin D
BD
D004784:Environmental Monitoring / Q000379:methods; D005456:Fluorescent Dyes; D005998:Glycine / Q000031:analogs & derivatives / Q000032:analysis; D006016:Glycolates / Q000032:analysis; D006540:Herbicides / Q000032:analysis*; D007093:Imidazoles / Q000032:analysis; D009525:Niacin / Q000031:analogs & derivatives / Q000032:analysis; D010573:Pesticide Residues / Q000032:analysis*; D010846:Picloram / Q000032:analysis; D012235:Rhodamines; D014197:Trees; D000097797:Glyphosate
D005456:Fluorescent Dyes; D005998:Glycine; D006016:Glycolates; D006540:Herbicides; D007093:Imidazoles; D009525:Niacin; D010573:Pesticide Residues; D010846:Picloram; D012235:Rhodamines; D000097797:Glyphosate; C222011:rhodamine WT; C052969:3,5,6-trichloro-2-pyridinyloxyactic acid 2-butoxyethyl ester; C076656:imazapyr