Using a plant bioassay to detect herbicide residue
Date
2005-02-17
Authors
Watson, P.R.
Checkel, S.
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
Type
Poster Presentation
Degree Level
Abstract
Soil residual herbicide activity has been investigated since the early 1960s. One objective has been to provide producers with specific re-crop recommendations. Numerous plant bioassays have been developed to meet this need. The Alberta Research Council (ARC) has been providing a bioassay service to detect symptoms consistent with herbicide carryover since 1986. The objective of this paper is to describe our bioassay methodology and to provide basic information arising from our experience. Soil samples suspected of containing active residues are submitted to the ARC. Once the soil sample is received, the target crop and a sensitive species are planted in both the submitted soil and a check soil, known to be herbicide-free. Samples are evaluated for initial severity of symptoms and recovery over time. Symptoms consistent with herbicide carryover were found in 77% of all samples submitted. The most common crop-herbicide type combination requested is canola-imidazolinone. The primary limitation of bioassays is that damage in the bioassay may not reflect yield loss in a producer’s field. However, bioassays are the only risk-management tool available to producers and can detect the presence of residues below chemical detection thresholds.
Description
Keywords
soil residual activity, whole-plant bioassay
Citation
Degree
Department
Program
Advisor
Committee
Citation
Part Of
Soils and Crops Workshop