Agriculture: Alfalfa Pest Management Guidelines

Susceptibility of Winter Weeds to Herbicide Control in Established Alfalfa

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
Barley, hare N N C P P C P N C C C C N P C
Bluegrass, annual N N C C C P C P P P C P C N N C
Bluegrass, bulbous N N N N C P N C C N N P
Brome, downy N N C P C C C N C C C C N C C
Canarygrasses N N P C C C P P C C P C N C C
Cereal, volunteer N N C C C C P N P C P C N P N
Chickweed, common N P N C C C C C P C C C P C C N P
Fiddlenecks (seedling) N C N C P C C C P C P P C C N C
Filarees (seedling) P C N C N C C C C C N N N P N N
Fleabane, hairy P C N N C C C N N C N C N N
Flixweed C C N C N C C C C N C C N N
Groundsel, common N P N N P C C C C P P N P N C N N
Lettuce, prickly C C N P C C C C N C N P N C N N
Mallow, little (cheeseweed) (seedling) N C N P N C C C P C C P N P C N N
Miner's lettuce N P N C N C C C C C P C C N C
Mustards C C N P N C C C C C C C P P C N N
Nettle, burning P C N C P C P C C C C N P N C N C
Oat, wild N N C N C C C P P N C P P N C N
Pepperweeds C N C N N P P C C N C N N N
Radish, wild N C N C N C C C C C C P N C N N
Rocket, London P C N C P C C C C C C C C P C N N
Ryegrass, Italian N N C P C C/P^ C N C C C C N C C
Shepherd's-purse P C N C P C C C C C C C P P C N N
Sowthistles C C N P C P C C C N N P N N C N C
Starthistle, yellow C N C C C C C N C N P N N 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 SL 2.0) 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 (Treflan, Trilin) 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: 03/17