Submitted to: Weed Technology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/12/2005
Publication Date: 12/1/2005
Citation: Williams, M., Boydston, R.A. 2005. Alternative to handweeding volunteer potato (Solanum tuberosum)in carrot (Daucus carota). Weed Technology. 19(4):1050-1055. Interpretive Summary: Weed management in domestic carrot production is characterized by high yield loss potential, few herbicides, and heavy reliance on handweeding. The most troublesome weed in carrot is volunteer potato and no herbicides are registered for control of the weed. Studies conducted over 4 site-years demonstrated that specific rates of prometryn or ethofumesate were safe on carrot and controlled volunteer potato similar to handweeding. This impact of this research is new tools have been identified for weed management systems in carrot that could help modernize domestic carrot production.
Technical Abstract: Few herbicides are used in carrot production in the U.S.A and none suppress volunteer potato, a serious weed where the two crops are grown in rotation. Handweeding is the primary method of controlling emerged volunteer potato within carrot. The objective of this work was to evaluate carrot tolerance and volunteer potato control with single or sequential applications of prometryn, prometryn plus fluroxypyr, and ethofumesate. The treatment with fluroxypyr resulted in malformed carrots with numerous root hairs and reduced carrot yield. Treatments with prometryn, either as single or sequential postemergence (POST) applications at 2.23 kg ai/ha, were safe on carrot and frequently controlled volunteer potato similar to the handweeded treatment. Ethofumesate applied as single or sequential preemergence (PRE) or POST at 2.2 kg ai/ha proved safe on carrot, but higher rates reduced yield. Ethofumesate applied POST or PRE followed by POST consistently reduced volunteer potato tuber mass. If registered for use in carrot, prometryn and ethofumesate would help modernize weed management in carrot and reduce or eliminate the need for handweeding volunteer potato.