Numerous weedy species in the pigweed family (Amaranthaceae) are found across Iowa, including waterhemp, redroot pigweed, smooth pigweed, Powell amaranth and others. At this time, Palmer amaranth has not been confirmed in the state, but because of its presence in surrounding states we suspect it may be here, or will appear in the near future

Hartzler, Robert G.

Owen, Michael D. K.

Numerous weedy species in the pigweed family (Amaranthaceae) are found across Iowa, including waterhemp, redroot pigweed, smooth pigweed, Powell amaranth and others. At this time, Palmer amaranth has not been confirmed in the state, but because of its presence in surrounding states we suspect it may be here, or will appear in the near future.</p

Hartzler, Robert

Owen, Michael

Digital Repository @ Iowa State University (ISU)

4/13/2014 Palmer amaranthhttp://www.extension.iastate.edu/CropNews/2013/0604hartzler.htm 1/2PRINT STORYEMAIL STORYADD TO DELICIOUS ATOM FEEDFOLLOW ON TWITTER Subscribe to CropNewsArchives2014201320122011201020092008 Previous YearsISU Crop ResourcesExtension FieldAgronomistsCrop & Soils InfoPesticide ApplicatorTrainingAgronomy ExtensionEntomology ExtensionPlant PathologyExtensionAg and BiosystemsEngineering ExtensionAgribusinessEducation ProgramIowa Grain QualityInitiativeCollege of Agricultureand Life SciencesISU ExtensionIs it Palmer Amaranth?By Bob Hartzler and Mike Owen, Department of AgronomyNumerous weedy species in the pigweed family (Amaranthaceae) are foundacross Iowa, including waterhemp, redroot pigweed, smooth pigweed,Powell amaranth and others. At this time, Palmer amaranth has not beenconfirmed in the state, but because of its presence in surrounding states wesuspect it may be here, or will appear in the near future (see April 24 ICMarticle).Identifying infestations of Palmer amaranth when they first get started is thekey to preventing its spread in Iowa. It is difficult to differentiate vegetativeplants of waterhemp and Palmer amaranth. Both have glabrous (hairless)stems and both species have variable leaf shapes. Purdue University recently published an article and video providinginformation on differentiating Palmer amaranth and waterhemp. They statethat Palmer amaranth frequently has a single hair in the notch found at theleaf tip, and that this trait is a reliable way to differentiate the two species. Wehave examined waterhemp plants and photos of waterhemp, and find thatthis hair is commonly present on waterhemp in Iowa. Thus, we do notrecommend this as a trait for differentiating the two species.Palmer amaranth frequently (but not always) produces leaves with a petiolemuch longer than the leaf blade. This probably is one of the most consistentvegetative traits for separating the two species but it also is variable. Plantswith inflorescences present are best to identify and confirm the Amaranthusspecies.We are willing to aid in identifying any plants suspected of being Palmeramaranth. In most cases, digital images will be insufficient to differentiatevegetative Palmer amaranth and waterhemp. Contact us via e-mail or phoneto determine how to proceed in confirming the identification of any suspectedICM Home ISU Extension Calendar Publications Extension News County Offices Contact Us4/13/2014 Palmer amaranthhttp://www.extension.iastate.edu/CropNews/2013/0604hartzler.htm 2/2Copyright ©2014 Iowa State University Extension | Iowa State UniversityContact us | For Staff | Nondiscrimination and Information Disclosures | CMS AdminLast Updated 6/5/2013Palmer amaranth. Bob Hartzler and Micheal Owen are professors of agronomy and weedscience extension specialists with responsib ilities in weed management andherb icide use. Hartzler can be reached at hartzler@iastate.edu or 515-294-1164. Owen can be reached at mdowen@iastate.edu or 515-294-5936. This article was published originally  on 6/4/2013 The inf ormation contained within the article may  ormay  not be up to date depending on when y ou are accessing the inf ormation.Links to this material are strongly  encouraged. This article may  be republished without f urtherpermission if  it is published as written and includes credit to the author, Integrated CropManagement News and Iowa State Univ ersity  Extension. Prior permission f rom the author isrequired if  this article is republished in any  other manner.

Is it Palmer Amaranth?

http://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1065&context=cropnews

Is it Palmer Amaranth?

Abstract

Similar works

Full text

Available Versions

Digital Repository @ Iowa State University (ISU)