Pigweed ID

Fe7955e7f06f80359dcde6ad64c7b82f?s=47 Joe Armstrong
January 16, 2012

Pigweed ID

Fe7955e7f06f80359dcde6ad64c7b82f?s=128

Joe Armstrong

January 16, 2012
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    WEED ID REFRESHER: Pigweed species Joe Armstrong Oklahoma State University

    Weed Science www.weedscience.okstate.edu Twitter: @OSUWeedSci
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    Generally speaking, identification of individual pigweed species is not necessary

    to choose the correct herbicide for maximum control. However, due to the development of herbicide-resistance in populations of waterhemp and Palmer pigweed in Oklahoma and the US, it is increasingly important to properly identify each weed to develop an appropriate management strategy.
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    All pigweeds, regardless of species, typically have a small notch

    in the tip of the true leaves. © Joe Armstrong, Oklahoma State University
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    © Joe Armstrong, Oklahoma State University Seeds of the various

    pigweed species are small, brown or black, round, and shiny. Because of their size, the seeds are easily moved in soil, with seed, or on equipment
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    redroot pigweed Note the short hairs on the stem. ©

    Joe Armstrong, Oklahoma State University
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    waterhemp The leaves are very waxy and shiny. © Joe

    Armstrong, Oklahoma State University
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    Palmer pigweed Palmer pigweed has wide, egg-shaped leaves. Often, they

    will have a white or purple “V” watermark. © Joe Armstrong, Oklahoma State University
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    Palmer pigweed Palmer pigweed also has waxy, shiny leaves. Note

    the absence of the watermark. © Joe Armstrong, Oklahoma State University
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    Palmer pigweed Unlike redroot pigweed, Palmer pigweed has a smooth,

    hairless stem. © Joe Armstrong, Oklahoma State University
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    Palmer pigweed waterhemp Palmer pigweed can also be identified by

    the long petiole, or the stalk that connects the leaf blade to the stem. This causes the leaves to hang out far away from the main stem. © Joe Armstrong, Oklahoma State University
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    Palmer pigweed Seedheads on Palmer pigweed plants are usually 1-2

    feet in length. © Joe Armstrong, Oklahoma State University
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    tumble pigweed Tumble pigweed is usually the easiest pigweed species

    to identify. As the name suggests, it grows in a low, round shape. © Joe Armstrong, Oklahoma State University
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    tumble pigweed Tumble pigweed also has more rounded leaf tips

    and wrinkled leaf margins than the other pigweeds. © Joe Armstrong, Oklahoma State University
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    All photos, unless noted, were taken by Joe Armstrong. If

    you would like high resolution versions of these photographs, please contact Joe at joe.armstrong@okstate.edu.