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.
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
Christopher A
CA
Nowak
Benjamin D
BD
Ballard
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