Two experiments were designed to study efficacy and uptake and translocation of an ester formulation of triclopyr (3,5,6-trichloro-2-pyridinyloxyacetic acid) in four solvents, aromatic solvent, aliphatic solvent, vegetable oil, and kerosene following stem applications to red maple (Acer rubrum), white oak (Quercus alba), and Virginia pine (Pinus virginiana). Another objective was to explore correlations between efficacy and uptake and translocation. Additional objectives included examining the influence of concentration, dose, and stem diameter on efficacy and the influence of bark thickness and season of treatment on uptake and translocation. Concentration ranged from 0.25 to 1 lb a.e./gallon in the efficacy study and was 1 lb a.e./gallon in the uptake study. Dose ranged from 0.4 to 2 ml/cm of stem diameter in the efficacy study and was 0.15 ml/cm of stem diameter in the uptake study. Efficacy evaluations were made 14 months following treatment in June. C¹⁴- triclopyr was used to determine uptake and translocation. Saplings in the uptake study were harvested three weeks following treatments in February, May, and July.
Aliphatic solvent, vegetable oil, and kerosene treatments resulted in excellent crown volume control, largely independent of concentration, dose, and stem diameter. Aromatic solvent gave poorer results, dependent on concentration, dose, and stem diameter, except among the maples. Herbicide uptake with the vegetable oil treatment was greatest. The other solvents provided similar levels of uptake. Uptake was greatest among the maples, the thinnest-barked species, and about equal in the oaks and pines.
Discrepancies between solvent differences in the efficacy and the uptake studies may have been, in part, a consequence of smaller doses used in the uptake study along with conditions which likely promoted greater solvent evaporation than those under which the efficacy study was performed. Faster evaporation of the kerosene and aliphatic solvents may have reduced their penetration of the outer bark while slower evaporation of aromatic solvent and vegetable oil likely had less influence on their penetration.
Stem diameter correlated negatively with crown volume control, despite basing dose on stem diameter, suggesting that the square of diameter, or stem volume, may be a more appropriate basis for determining doses. Uptake correlated negatively with bark thickness. Uptake did not vary significantly among seasons but translocation did. Movement to the leaves occurred following the May and July treatment but virtually none to leaves or buds following the February treatment. The high degree of sprouting which occurred among saplings in the May treatment compared with none among saplings in the July treatment would suggest that downward translocation of herbicide was greater in July. / Master of Science
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/45340 |
| Date | 31 October 2009 |
| Creators | Schneider, William Grant |
| Contributors | Forestry |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Thesis, Text |
| Format | 79 leaves, BTD, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | OCLC# 25404088, LD5655.V855_1991.S3555.pdf |
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