About Us | Help Videos | Contact Us | Subscriptions
 

Abstract

 

This article in CM

  1. Vol. 5 No. 1
     
    Accepted: Mar 07, 2006


    * Corresponding author(s): mjv@udel.edu
 View
 Download
 Alerts
 Permissions
Request Permissions
 Share

doi:10.1094/CM-2006-0420-01-RS

Paraquat-Resistant Horseweed Identified in the Mid-Atlantic States

  1. Mark J. VanGessel *,
  2. Barbara A. Scott and
  3. Quintin R. Johnsona
  1. a Department of Plant and Soil Science, University of Delaware, Georgetown 19947

Abstract

In 2003, a small percentage of horseweed (Conyza canadensis) plants survived sequential paraquat applications in a research trial conducted in a commercial field. This research project focused on determining if this horseweed population was resistant to paraquat. The susceptible biotype required a paraquat application of 0.03 lb ai/acre to reduce biomass by 50%, while the suspected-resistant biotype required 0.7 lb ai/acre. This consists of a 22-fold difference in response between the two biotypes. This is the first documented case of paraquat-resistant horseweed in the Mid-Atlantic states and the second reported case in the United States for this species.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © 2006. © 2006 Plant Management Network.