TY - JOUR
T1 - Within-field soil heterogeneity effects on herbicide-mediated crop injury and weed biomass
AU - Williams, Martin M.
AU - Mortensen, David A.
AU - Martin, Alex R.
AU - Marx, David B.
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2001
Y1 - 2001
N2 - Soil organic carbon (OC), clay content, water content, and pH often influence the bioactivity of soil-applied herbicides, and these soil properties can vary greatly within fields. The purpose of this work was to determine the influence of within-field soil heterogeneity on the efficacy of RPA-201772 where corn, shattercane, and velvetleaf were seeded as bioassays. An experimental approach was developed to quantify RPA-201772 dose-response across a range of soil conditions in an agricultural field. Based on a logistic model, crop injury was quantified with the I20 parameter, the dose eliciting 20% greenness reduction, using a series of photographic standards. Weed biomass was quantified with the I80 parameter, the dose eliciting 80% biomass reduction, relative to the untreated control. Crop and weed responses varied by two orders of magnitude. Significant correlation, as high as 0.76, was observed between measures of plant response and soil properties, namely particle size and OC. Furthermore, native velvetleaf spatial distribution at the study site was heterogeneous, and seedlings were observed in plots where seeded velvetleaf biomass was high. Spatial heterogeneity of soil affinity for herbicide results in differential weed fitness and contributes to weed "patchiness.".
AB - Soil organic carbon (OC), clay content, water content, and pH often influence the bioactivity of soil-applied herbicides, and these soil properties can vary greatly within fields. The purpose of this work was to determine the influence of within-field soil heterogeneity on the efficacy of RPA-201772 where corn, shattercane, and velvetleaf were seeded as bioassays. An experimental approach was developed to quantify RPA-201772 dose-response across a range of soil conditions in an agricultural field. Based on a logistic model, crop injury was quantified with the I20 parameter, the dose eliciting 20% greenness reduction, using a series of photographic standards. Weed biomass was quantified with the I80 parameter, the dose eliciting 80% biomass reduction, relative to the untreated control. Crop and weed responses varied by two orders of magnitude. Significant correlation, as high as 0.76, was observed between measures of plant response and soil properties, namely particle size and OC. Furthermore, native velvetleaf spatial distribution at the study site was heterogeneous, and seedlings were observed in plots where seeded velvetleaf biomass was high. Spatial heterogeneity of soil affinity for herbicide results in differential weed fitness and contributes to weed "patchiness.".
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U2 - 10.1614/0043-1745(2001)049[0798:wfsheo]2.0.co;2
DO - 10.1614/0043-1745(2001)049[0798:wfsheo]2.0.co;2
M3 - Article
AN - SCOPUS:0006952180
SN - 0043-1745
VL - 49
SP - 798
EP - 805
JO - Weed Science
JF - Weed Science
IS - 6
ER -