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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research » Research » Research Project #433633

Research Project: Assessing Carryover Potential for Several Herbicides in Field Peony Nurseries

Location: Horticultural Crops Research

Project Number: 2072-22000-041-17-G
Project Type: Grant

Start Date: Sep 1, 2017
End Date: Sep 30, 2019

To evaluate the potential for carryover of dithiopyr, indaziflam, isoxaben, oryzalin, and pendimethalin to injure rotationally-grown peony stock after transplanting in the field.

Two rates each (minimum and maximum labeled rates) of dithiopyr, indaziflam, isoxaben, oryzalin, and pendimethalin will be applied to bare soil in 44 plots. Plots will be tilled immediately after treatment to mix the herbicide into soil and to mimic the distribution the herbicide would have following a rotationally-grown crop. Nontreated control plots will be tilled first, followed by low and high rates of each herbicide. Plant materials will be planted into each treated plot. Visual weed control and injury percentages will be estimated periodically during the growing season. The ornamental plant material will be lifted at onset of dormancy and all plants will be weighed, above- and below-ground growth measured, and observed for abnormalities in growth (crooked stems, swellings at the soil line, etc.).