8Foliar Spray Foliar spraying—complete control is difficult Care must be taken to apply herbicide to every branchIncreased the risk of contaminating the environment or damaging non-target plants.Dilution of the chemical is usually required.
9Basal Bark SprayApply herbicide to the lower area of the main trunk(s) of the treeChemical is absorbed through the barkReduced the risk of environmental contaminationLess effective on trees with corky barkPenetrating oil or diesel may help with absorption to cambium
10Frill CutCut notches through the bark and into the sap wood of the treeUndiluted herbicide is poured or injected into each notchCuts are made with a downward motion so the notches will hold the herbicideDo not girdle the tree with the chop marks.Environmentally friendly application method that makes very efficient use of herbicideThe main difficulty is getting through the thorny lower branches of the tree to access the trunkUndiluted herbicide is applied in small amounts (2cc or less per inch of trunk diameter)
12Stump CutThe tree is cut down and the stump is immediately (within ten minutes) sprayed or painted with herbicideCutting down the tree and applying the chemical immediately usually requires two or more people to accomplishAnecdotal evidence indicates this may not be as effective as the frill cut methodUndiluted chemical is more effective with this application method
13Experiment DesignUsed the Frill Cut method for accuracy of placement and ease of meteringThree chemicalsHabitat (Arsenal)—28.7%2-4,D—47.3%Roundup—41.0%Three rates (cc/inch trunk diameter)1.001.502.00Control trees were cut and marked but nothing was applied to the cuts
22ResultsThe frill-cut method is effective and reduces environmental contaminationLower application rates appear to be as effective as the higher ratesNo significant difference in the effectiveness of the different chemicals usedThe greatest cost, regardless of chemical and application method, is labor to remove the plants
23Recommendations Treat trees with the frill-cut method Take care to not girdle the tree with frill cutsApply 1.0 cc of undiluted chemical into each cutUse of a soil-active chemical could hinder re-vegetation efforts