Agriculture: Alfalfa Pest Management Guidelines

Susceptibility of Spring and Summer Weeds to Herbicide Control in Established Alfalfa

Susceptibility of Spring/Summer Weeds in Established Alfalfa to Herbicide Control
24DB* CAR CLE DIU EPT FLU GLY+ HAL HEX IMA MET NOR PAR* PEN SAF SET TRI1
Mode of Action 4 14 1 7 8 14 9 2 5 2 5 12 22 3 14 1 3
ANNUAL WEEDS
Barnyardgrass N N C P C C P C C C P C N C C
Cupgrass, prairie N N C P P C P N C P N C C
Dodders N P N N N C N P N N P C P N C
Foxtail, green N N C C C C C C P C N C C
Foxtail, yellow N N C P C C C C P C N C N C C
Goosefoot, nettleleaf C N C C C C C P C C C C N N C
Goosegrass N N C C C P P C P C N C
Junglerice N N C C C C C P P C P N C C
Knotweed, prostrate P C N C P C C C C N P P C C N C
Lambsquarters, common C C N C C C C N C P P P N C C N P
Nightshades C C N C C C C N C C N C P N C N N
Pigweeds C C N C C C C P C C C C P C C N C
Stinkgrass N N C C C P N P C P N C C
Thistle, Russian P C N N P C P P P C P P C N P
Witchgrass N N C N C C P N C C P N C C
PERENNIAL WEEDS
Barley, foxtail N N C P P C P N C C P N C P
Bermudagrass (established) N N P N N C N N N N P N N N P N
Bermudagrass (seedling) N N C N C C N P P N C P C N C C
Bindweed, field (established) P N N N N N P N N N N N N N N N P
Bindweed, field (seedling) C C N P N C C N P P P C N P
Dandelion (established) C P N N N C P N P N P N P N N
Dandelion (seedling) C C N C C C C P C N N N C N N
Johnsongrass (established) N N C N N C N P N C N N N C N
Johnsongrass (seedling) N N C C C C C C N C C C N C C
Nutsedge, yellow N N N N P P P C N P P P N N N N N
Plantain, buckhorn (seedling) C C N C C C C C N
Plantain, buckhorn (established) P N N N P P N N N N N N N N
Quackgrass N N P P C P P N N L N
C= control    P= partial control    N= no control    = no information
NOTE: Weed size and spray coverage affect weed control as will herbicide rate, adjuvant type, spray volume, and environmental conditions.
24DB = 2,4-DB* (Butyrac) MOA: 4      IMA = imazethapyr (Pursuit) (highest rate) MOA: 2
CAR =carfentrazone (Shark) MOA: 14 MET = metribuzin (Tricor DF) MOA: 5
CLE = clethodim (Select Max)) MOA: 1 NOR = norflurazon (Solicam) MOA: 12
DIU = diuron (Karmex) MOA: 7 PAR = paraquat* (Gramoxone) MOA: 22
EPT = EPTC (Eptam) MOA: 8 PEN = pendimethalin (Prowl H2O) MOA: 3
FLU = flumioxazin (Chateau) MOA: 14 SAF =saflufenacil (Sharpen) MOA: 14
GLY1 = glyphosate (Roundup) MOA: 9 SET = sethoxydim (Poast) MOA: 1
HAL = halosulfuron (Sandea) MOA: 2 TRI = trifluralin1 (Trifluralin) MOA: 3
HEX = hexazinone (Velpar) MOA: 5      
* Permit required from county agricultural commissioner for purchase or use.
+ For use in Roundup Ready alfalfa only.
1 Not usually applied at times suitable for controlling winter weeds.
▽ Group numbers are assigned by the Weed Science Society of America (WSSA) according to different modes of action. Although weeds may exhibit multiple resistance across many groups, mode-of-action numbers are useful in planning mixtures or rotations of herbicides with different modes of action.
Text Updated: 04/24
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