Most Troublesome Weeds in Midsouth Soybeans
A survey was conducted in 2016 by the Weed Science Society of America (WSSA) to identify the most troublesome and difficult-to-control weeds in 12 categories of broadleaf crops, fruits, and vegetables. The following table contains results that are specific to Midsouth soybeans. The state and affiliation [Affil. = University (Univ.) or Industry (Ind.)] columns indicate the state and affiliation of the respondent.
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Top 5 most troublesome weeds in Midsouth soybeans |
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State |
Affil. |
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1 |
2 |
3 |
4 |
5 |
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Ark. |
Univ. |
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Palmer amaranth |
Marestail |
Yellow nutsedge |
Asiatic dayflower |
Sicklepod |
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Ark. |
Ind. |
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Palmer amaranth |
Ivyleaf MG |
Pitted MG |
Barnyardgrass |
Broadleaf signalgrass |
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Ark. |
Univ. |
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Palmer amaranth |
Barnyardgrass |
Pitted MG |
Ivyleaf MG |
Prickly sida |
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Ark. |
Univ. |
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Palmer amaranth |
Ipomoea spp. |
Sicklepod |
Yellow nutsedge |
Broadleaf signalgrass |
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La. |
Univ. |
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Ipomoea spp. |
Palmer amaranth |
Browntop millet |
Cyperus spp. |
Redvine |
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Miss. |
Univ. |
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Palmer amaranth |
Ipomoea spp. |
Horseweed |
Yellow nutsedge |
Barnyardgrass |
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Miss. |
Ind. |
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Palmer amaranth |
Waterhemp |
Common LQ |
Prickly sida |
Ivyleaf MG |
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Tenn. |
Ind. |
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Palmer amaranth |
Ivyleaf MG |
Johnsongrass |
Goosegrass |
Barnyardgrass |
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Tenn. |
Ind. |
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Horseweed |
Palmer amaranth |
Yellow nutsedge |
Prickly sida |
sicklepod |
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Tenn. |
Ind. |
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Palmer amaranth |
Common cocklebur |
Sicklepod |
Ipomoea spp. |
Horseweed |
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Tenn. |
Univ. |
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Palmer amaranth |
Ipomoea spp. |
Giant ragweed |
Yellow nutsedge |
Prickly sida |
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Ipomoea spp. = morningglory species; MG = morningglory; LQ = lambsquarters; Cyperus spp. = sedges; Horseweed likely synonymous with marestail. |
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Of the surveyed respondents in the Midsouth, four were in Arkansas, one was in Louisiana, two were in Mississippi, and four were in Tennessee. Respondents from both industry and university affiliations were represented.
Not surprisingly, in all states except Louisiana, Palmer amaranth [Palmer pigweed] was overwhelmingly listed as the most troublesome weed. The one Louisiana respondent and one of the four Tennessee respondents listed it as the second most troublesome.
Annual grasses [barnyardgrass, browntop millet, or broadleaf signalgrass] were listed in the top five by at least one respondent from each state.
Morningglory species were listed in the top five by one or more respondents from each state. In fact, morningglory species were listed as the most troublesome weeds in Louisana.
Prickly sida was listed as the fourth or fifth most troublesome weed by one or more respondents from Arkansas, Mississippi, and Tennessee.
Yellow nutsedge was listed as the third or fourth most troublesome weed by two Arkansas respondents, fourth most troublesome by one Mississippi respondent, and as the third or fourth most troublesome by two Tennessee respondents.
Sicklepod was listed as the third or fifth most troublesome weed by two Arkansas respondents and by two Tennessee respondents.
Horseweed or marestail was listed in the top five by respondents from Arkansas, Mississippi, and Tennessee. In fact, one of the four Tennessee respondents rated it as the most troublesome weed in that state. This is one of the first weeds to be identified as glyphosate-resistant.
One piece of good news from the survey is that Johnsongrass was listed as one of the top five [third] most troublesome weeds by only one respondent [from Tennessee]. Thus, it appears that this once formidable weed pest is being controlled sufficiently by present management tools.
According to Dr. Lee Van Wychen, science policy director of WSSA and author of the report, the most troublesome weeds in the list are likely there because “there is no question that their difficulty to control with herbicides has pushed them to the top of the list in this survey”.
Complete results of the survey can be found here.
Composed by Larry G. Heatherly, May 2017, larryheatherly@bellsouth.net