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Ohio fall weed survey

By Harold Watters, Ohio State University Extension agronomist

Once again your county Extension professionals went to the fields this fall to see what weeds made it through the summer in your soybean fields. There were some surprises and some expected results. It is becoming apparent that with the move to herbicide tolerant crops, we aren’t necessarily getting rid of all of our weeds — only 30% of our fields are weed free. Giant ragweed moved back into first place for worst weed, seen in 34% of fields and overtaking marestail seen in 30% of fields. Volunteer corn is next most common, and it always surprises farmers that a herbicide resistant crop would also resist the same herbicide when it volunteers the next year. Please look over the tables to see if there are familiar names on your worst weed list.

WeedOhio rank% of fields
Giant Ragweed134
Weed free330
Volunteer corn417
Grass/ Giant foxtail515
Velvet leaf79
Common ragweed88
Redroot pigweed105


I split up the state into regions — the areas of northwest and west central Ohio had the weediest fields, — as they have in the recent past.

Weed free by regionPercent
East central42%
North central46%
West central24%


The county Extension educators did all the leg work. Folks in 28 counties did the surveys this year — and I have to mention them by name. Because they were out a day or two to conduct these surveys we have a record of the problems you have, so we can better assist you in controlling those weeds. Sometimes just knowing what is out there can help you direct the herbicide program to best manage the problem.

Survey results by OSU Extension
Number of fields2,793
Total number of acres159,121
Average field size (acres)57


County evaluated (28)OSU Extension AgNR
AshtabulaLee Beers
AuglaizeJeff Stachler
ChampaignAmanda Douridas
ClintonTony Nye
CoshoctonDavid Marison
CrawfordJason Hartschuh
DarkeSam Custer
DefianceBruce Clevenger
FayetteKen Ford
FultonEric Richer
GeaugaLes Ober
GreeneTrevor Corboy
HancockEd Lentz
HardinMark Badertscher
HenryGarth Ruff
LickingDean Kreager
MadisonMary Griffith
MercerDenny Riethman
MiamiAmanda Bennett
MontgomerySuzanne Mills-Wasniak
MuskingumClifton Martin
PauldingSarah Noggle
PortageRobin Christensen
PutnamBeth Scheckelhoff
ShelbyDebbie Brown
TrumbullLee Beers
TuscarawasChris Zoller
WilliamsJohn Schoenhals


Oh, and the big surprise this year was the pigweed problem. Waterhemp appeared frequently and so did redroot pigweed. Three years ago these weeds were not even on our lists and now Waterhemp appeared in 35% of the fields in northwest Ohio and 22% in west central. This requires some management changes.


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