Cooperative
Extension
Service


University of Illinois
at
Urbana-Champaign


No. 5/April 27, 1998

Multi-State Weed Control Ratings

For many years, we have included various tables of herbicide effectiveness inchapters of the Illinois Agricultural Pest Management Handbook. Within these tables, we assign numeric efficacy ratings to various herbicides for control of a number of agronomically important grass and broadleaf weed species. Our numeric scale ranges from 0 (no control) to 9 (excellent control). Several other states in the north central region also rate many of the same herbicides on similar (or sometimes different) weed species, but not always using an identical rating scale. Some states utilize a "letter" scale in lieu of anumeric rating system. These letter scales can have different ranges also: Some range from excellent to poor (that is, excellent, good, fair, poor), while others range from good to poor (that is, good, fair, poor). Also, be aware that other states' numeric rating scales can vary. Each type of scale has its own set of advantages and disadvantages, and none is generally assumed to be superior to the others.

Marshal McGlamery has undertaken the task of summarizing data from several states in the north central region and has produced several summary efficacy rating tables for corn and soybean herbicides. He used the most recent state ratings at his disposal, but be aware that ratings can and often do change frequently. If Extension specialists from states whose ratings we have summarized note any errors, please contact us.

The first set of tables, included in this issue of the Bulletin, summarizes efficacy ratings of corn herbicides for control of various grass weed species. As is evident from these tables, not all states in the north central region rate the same spectrum of weeds and not all states use the same rating system. Most of the following tables are single-species tables, but some tables contain data for two species (for example Table 6 contains ratings for giant and yellow foxtails). In tables for two species, the first rating in a column indicates that state's rating for the herbicide's efficacy on the first species listed in the title of the table. For example, in Table 6, Illinois rates giant foxtail control with Liberty as "8" and yellow foxtail control as "7."

In future issues of this Bulletin, we will present additional tables for corn herbicide effectiveness ratings on broadleaf species and soybean-herbicide efficacy ratings for grass and broadleaf species.

Table 3. Efficacy of corn herbicides: Barnyardgrass.
IA1ILINKSKYMIMOMNNBOHPAWSAvg
Soil-
applied
Axiom92------------
Dual IIE99E8E8G989GE9
FrontierE99E8E8G989GE9
Harness
/Surpass
E99E8E8G999GE9
LassoE99E8E8G989GE9
EradicaneE9-E-E9G999G9
Prowl
--PRE
GE89GE8G9-888+G8+
Post-
emergence
AccentE98GE8E9G88+8+GE8+
Accent Gold-8-GE---------
BasisF77GE-G-G778G7+
Basis Gold-88GE8G-G88+8+G8
BeaconP47-3P0P226P4
LibertyG77FG7F8F778F7+
Lightning-88G-F-G878GE8

<’TD>EGFMP
1State2Scale3"Letter" key
IA--IowaEGFP3E--Excellent
IL--Illinois0-9G--Good
IN--Indiana0-9F--Fair
KS--KansasEGFPM--Marginal
KY--Kentucky0-9P--Poor
MI--MichiganEGFPNN--None
MO--Missouri0-10
MN--MinnesotaGFPN
NB--Nebraska1-10
ND--North DakotaEGFPN
OH--Ohio0-9
PA--PennsylvaniaN-6-10
SD--South Dakota
WS--WisconsinEGFP

Table 4. Efficacy of corn herbicides: Crabgrass.
IA1ILINKSKYMIMOMNNBOHPAWSAvg
Soil-
applied
Axiom-92-----------
Dual IIE99E8E9G999GE9
FrontierE99E8E9G999GE9
Harness
/Surpass
E99E8E9G999GE9
LassoE99E8E9G999GE9
EradicaneE9-E8E9G999E9
Prowl
--PRE
GE89G8G8-999E8+
Post-
emergence
AccentP56F5P6P246P5
Accent Gold-6-F---------
BasisF65F6P-P767P6
Basis Gold-65G-P-P747+P6
BeaconP45-5P0P246P4
LibertyE88G7F7F8-9G8
Lightning-76G-F-G778G7+

Table 5. Efficacy of corn herbicides: Woolly cupgrass.

<
IA1ILINMOMNWSAvg
Soil-
applied
Dual IIF2777GF7
FrontierF777GF7
Harness/SurpassFG888GF8
LassoF777GF7
EradicaneG8-8GF8
Prowl
--PRE
G887-F7+
Post-
emergence
AccentGE888FGE8
BasisF54-PP5
Basis Gold-66-FPF-
BeaconP322PP3
LibertyE888GG8
Lightning-87-GG8

Table 6. Efficacy of corn herbicides: Giant foxtail, yellow foxtail.

IA1ILINKSK
Y
MIM
O
MNN
B
OHP
A
WSAvg
Soil-
applied
Axiom-9-
92
-----------
Dual IIE9-99-9E8E-E9G-G99-99GE9-9
FrontierE9-99-9E8E-E9G-G99-99GE9-9
Harness/
Surpass
E9-99-9E8E-E9G-G99-99GE9-9
LassoE9-99-9E8E-E9G-G99-99GE9-9
EradicaneE9-9-E-E-E-G-G99-99E9-9
Prowl
--PRE
GE8-99-9G8G-G9-99-98+E8+-9
Post-
emergence
AccentGE9-88-8GE8E-E8G-G89-99GE8+-9
Accent Gold-8-8-GE---------
BasisG8-88-8GE-F-F-G-G87-78+G8-9
Basis Gold-8-89-8GE8G-G-G-G89-89G8+-8
BeaconPF6-57-5-6F-F3PP47-77F6-6
LibertyGE8-78-7E9G-F8F98+-89G8+-7
Lightning-8-88-7E9G-F-G88+-89GE8+-7

Table 7. Efficacy of corn herbicides: Fall panicum.

IA1ILINKSKYMIMOMNNBOHPAWSAvg
Soil-applied
Axiom-92-----------
Dual IIE99E9E9G98+8+GE9
FrontierE99E 9E 8G988+GE 9
Harness/SurpassE99E9E9G988+GE9
LassoE99E9E9G988+GE9
EradicaneE9-E9E9G999E9
Prowl--PREGE89G-G8-999E8+
Postemergence
AccentG88G7E8G88+9G8
Accent Gold---G---------
BasisFG88GE-F-G778+FG8
Basis Gold-88E-G-G889G8
BeaconFG79F6G7FG788FG7
LibertyG77G7F7G777+G7
Lightning-77E-F-G878G7+

Table 8. Efficacy of corn herbicides: Sandbur.

IL1KSMIMNNBNDSDWSAverage
Soil-applied
Axiom72--------
Dual II7FGFF5PM+F7
Frontier6FGFF4GMF6
Harness/Surpass7FGFF6GEMF7
Lasso6FGFF6FPM+F6
Eradicane8GFGG7GEG+G8
Prowl--PRE8GF-7FGG8
Postemergence
Accent8FGG8GEGG8
Accent Gold7G---GF+-7
Basis5FPP7FG-P6
Basis Gold7-GFG7GM+G7
Beacon6-FF4-MF6
Liberty7GPP7GG+F7
Lightning7GPG6EF+F7

Table 9. Efficacy of corn herbicides: Shattercane.

IA1ILINKSKYMONBOHPAAvg
Soil-applied
Dual IIF256P454565
FrontierF55P443565
Harness/SurpassFG56P464565
LassoF56P454565
EradicaneG8-G-88788
Prowl--PREG78F576677
Shattercane--Johnsongrass--Corn
Postemergence
AccentE9-99-9E-G9-89-9109-99+-8+9-9
Accent Gold-8-7-E-F------
BasisG8-47-0E--107-48+-78-5
Basis Gold-8-78-0E8-6-109-69-78-7
BeaconE9-89-7E-G9-710-8109-79+-89-8
LibertyE8-68-7G-F8-58-578+-78-68-6
Lightning-9-69-6E-F9-6-98+-79-78-6+

Table 10. Efficacy of corn herbicides: Quackgrass, wirestem muhly.

IA1ILINOHPAAverage
Postemergence
AccentG-F28-7899-78-7
BasisP-P-478-64-4
Basis Gold-6-568+8+-6+7-6
BeaconG-P8-578+8+-68-6

Table 11. Efficacy of corn herbicides: Yellow nutsedge.

IA1ILINKYMIMOMNOHPAWSAverage
Soil-applied
Dual IIG2787GF8FG8+8FG8
FrontierG787F7FG87+FG7
Harness/SurpassG787GF8FG8+7+FG7
LassoG787GF7FG87+FG7
EradicaneG8-7G8G8+9G8
Prowl--PREP030N0-00N0
Postemergence
AccentF655F2P66P6
BasisP5--N-N-6P6
Basis Gold-556F-P66+P6
BeaconF655F2F67F6
LibertyF54-P6P56P6
Lightning-66-F-P57-6

Aaron Hager (hagera@idea.ag.uiuc.edu) and Marshal McGlamery (mmcglame@uiuc.edu), Department of Crop Sciences, (217)333-4424