Vol. 15—1961 - NorthEastern Weed Science Society

418.
COMPARISONOF TECHNIQUESANDSPECIFIC HERBICIDESFOB.Tmt CONTllOL
OF BLACttLOCUST, SASSAFRAS,ANDStJHAC.1/
John P. Sterrett aa4 w. B. Chappell 1/
Virginia Agricultural ExperUaent Station
Blacksburg, Virg1n1a
The control of black locust, sassafras, aDd sumac bas been ODe of the
major problems in brush control. These trees are especially difficult to kill
because they not only sprout from the root crown but have the added ability to
produce suckers from underground parts as well.
The objective of this investigation was to evaluate the effectiveness of
specific herbicides and several methods of application on black locust, sassafras,
and sumac, and to compare the control of these woody plants with that
of associated species.
Procedure
The experiments were conducted in the field with chemicals and concentrations
that had shown promise in preVious field studies (tables I 6; 2). The
plots were located on the west slopes of utility rights-of-way at an elevation ­
of approximately 2,000 feet near Blacksburg, Virginia. The chemical mixtures
were applied with a 7-gallon per minute pump at a pressure of 200 pai for dormant
season oil mixtures and 400 psi for growing season water mixtures. A
trigger gun with a :fJ6 tip was used for both mixtures. Each chemical was applied
in twenty-five gallons of oil as a carrier during the dormant season and in
fifty gallons of water as a carrier during the growing season. The growing
season applications were made in July, 1959 and the dormant season applications
in January and April, 1960. Brush density and height determined the plot size.
The plots were replicated from three to four times and each plot was divided
into four equal parts to determine stem uniformity. All stems were counted
tmmediately after treatment and again at the end of the following growing season.
The second count was made in September, 1960. Original stems were
considered dead only if they were killed to the ground line. Ilegrowth from the
root croWD or underground. parts was counted and. designated resprouts.
!/ These studies were supported in part by research grants from the
Appalachian Power Company, The F. A. Bartlett Tree Expert Company, The Amchem
Products, Inc •• the Diamond Alltali Company, The DowChemical Company, and The
E. I. DuPont de Nemours & ComPanY. .
1/ Graduate Ilesearch Asslstant and Professor of Plant Physiology.