Control of an Oak(Quercus)Complex with Herbicide Granules

Abstract

Granule, and in some cases, tablet and ball formulations of bromacil (5-bromo-3-sec-butyl-6-methyluracil), dicamba (3,6-dichloro-o-anisic acid), picloram (4-amino-3,5,6-trichloropicolinic acid), karbutilate [tert-butylcarbamic acid ester with 3(m-hydroxyphenyl)-1,1-dimethylurea], and tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N′-dimethyl urea} were applied to three areas within 30 km of College Station in the Claypan Resource area of Texas. Woody species growing in the area included blackjack oak(Quercus marilandicaMuenchh.), post oak(Quercus stellataWangenh.), yaupon(Ilex vomitoriaAit.), winged elm(Ulmus alataMichx.), white ash(Fraxinus americanaL.), mockernut hickory(Carya tomentosaNutt.), and tree huckleberry(Vaccinium arboreumMarsh.). Granules were applied either broadcast or in rows at several intervals. Tebuthiuron was the most effective herbicide on oaks, winged elm, and white ash. Tebuthiuron and picloram were equally and most effective on yaupon, mockernut hickory, and tree huckleberry. Tebuthiuron + picloram at 2.2 + 2.2 kg/ha was the most effective herbicide treatment on huckleberry. However, a mixture of tebuthiuron + picloram (1:1 w/w) was usually no more effective than the same rate of tebuthiuron in the mixture applied alone. Tablet and ball formulations of karbutilate and tablet formulations of tebuthiuron were generally equally as effective as granules. Applications of picloram and tebuthiuron granules in rows 1.8, 3.0, 4.6, or 6.1 m apart gave control equal to broadcast applications except for picloram on yaupon. On yaupon all row spacing treatments of picloram were less effective than the broadcast treatment, whereas with tebuthiuron the 6.1-m spacing was least effective. Picloram and tebuthiuron granules applied in rows, approximately at 1.8-m intervals with a tractor, were as effective as granules applied by hand in straight rows.

Tebuthiuron Formulation and Placement Effects on Response of Woody Plants and Soil Residue

“…# QUESL), and sand shinnery oak (Quercus havardii Rydb. # QUEHV) (6,10,15,17,20,21). Tebuthiuron pellets at 2.2 kg/ha killed 75 to 100% of live oak growing on a gravelly sandy loam on the Coast Prairie (13,16).…”

Brush Response to Spacing and Individual-Plant Herbicide Treatments

“…Pelleted formulations of certain herbicides are effective for controlling woody plants. Blackjack oak, live oak, post oak, and other oaks have been controlled by pelleted fenuron (1,1-dimethyl-3-phenylurea), hexazinone [3-cyclohexyl-6-(dimethylamino) -1 -methyl -1,3,5-triazine -2,4 -(1H, 3 H) -dione], karbutilate [tm-butylcarbamic acid ester with 3 (m -hydroxyphenyl) -1,1-dimethylurea], picloram, and tebuthiuron (4,5,10,13,15,16,18,19,20,23,26,27). Honey mesquite has been controlled by karbutilate and, to a lesser extent, by tebuthiuron, but it is not sensitive to soil-applied picloram (6,12).…”

“…Tebu thiuron, however, was more effective on species of small stature such as whitebrush (Aloysia lycioides Cham.) and yaupon when applied broadcast rather than in rows 6 m apart (14,16). Furthermore, soil-active herbicides have been applied effectively both as large, widely-spaced pellets in broadcast applications by ground or aerial equipment (25,30) and as pellets or liquid formulations to individual woody plants (14,22).…”

Herbicide influence on foliar amino acid content in five representative southwestern range-plant species /

“…These herbicides will increase content of various amino acids, total crude protein, and other plant biochemical components and will improve growth and yield (see, for example, Ries et al 1963Ries et al , 1967Ries et al , 1968Ries and Gast 1965;Fink and Fletchall 1967; Pulver and Tweedy 1968;Baur et al 1970Baur et al , 1977; Arnold and Nalewaja 1971; Kay et al 1971;Tweedy et al 1971;Hiranpradit et al 1972;Singh et al 1972; Steenbjerg et al 1972; Houston and van der Sluijs 1973;and Jung and Blohm 1974). Many of these sometimes beneficial herbicides are used in the Southwestern United States for either general or specific weed control (see, for example, Meyer et al 1969Meyer et al , 1970Meyer et al , 1978 Byrd and Colby 1978;Meyer and Baur 1979;Jacoby et al 1980; and Meyer and Bovey 1980a, 1980b, 1980c. Of course, these herbicides vary in their effectiveness at controlling different species.…”