Date of Award

Summer 2014

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Botany and Plant Pathology

First Advisor

Richard Latin

Committee Member 1

Ronald Turco

Committee Member 2

Teresa Hughes

Abstract

Turf managers often rely on fungicides to limit damage caused by root diseases. Since fungicides do not move basipetally, they are effective only when fungitoxic concentrations are delivered to the rhizosphere. This research focused on the distribution of modern fungicides in verdure, thatch, sand, and roots of creeping bentgrass (Agrostis stolonifera L. var. palustris (Huds.) Farw.) maintained as a putting green. Fungicides (azoxystrobin (methyl (E)-2-[2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl]-3-methoxyacrylate), propiconazole (1,2,4-Triazole, 1-((2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl)methyl), pyraclostrobin (carbamic acid, [2-[[[1-(4-chlorophenyl)-1H-pyrazol-3-yl]oxy]methyl]phenyl]methoxy-,methyl ester), and thiophanate-methyl (dimethyl 4,4'-o-phenylenebis[3-thioallophanate]) were applied to replicate field plots in a water volume of 815 L ha-1. Plots were sampled over time (0, 3, 7, 10, 14, 17, 21 days after application) by extracting cores measuring 2 cm diameter by 3.8 cm deep. Cores were separated into verdure/thatch, sand, and roots before quantitative determination (liquid chromatography, triple quadrupole mass spectrometry) of fungicide residues. Fungicide residues in verdure/thatch declined steadily with time and support previously reported results describing fungicide depletion. Fungicides were detected in roots and sand within 5 hours of application, although at very low (1-15 ppm) concentrations. Residues in roots and sand remained at low levels throughout the experiment. Fungicides differed with respect to amounts recovered per turfgrass component.

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