Pacific Northwest Weed Management Handbook

Potato

Pamela J.S. Hutchinson

Revised:

March 2022

In this section

Herbicide Effectiveness on Weeds in Potatoes Revised March 2022
Herbicide Effectiveness on Grass weeds Revised March 2022

Herbicides Labeled for Use in Potato After Planting: Application Timing and Activity (Soil and Foliar)
Must be Applied Preemergence to Potatoes		Can be Applied Preemergence or Postemergence to Potatoes3		Postemergence Only
Foliar Active Only For Burndown of Emerged Weeds	Soil Active For Control of Weeds Not Yet Emerged	Soil Active Only Will Not Control Emerged Weeds	Both Soil and Foliar Active Can Control Non-Emerged and Emerged Weeds
carfentrazone-ethyl (Aim EC) In Canada can only be used as a pre-plant burndown glyphosate paraquat Not for use in Canada at this timing glyphosate + S-metolachlor (pre-mix) (Sequence)	dimethenamid-p (Outlook; Frontier Max in Canada) ethalfluralin (Sonalan HFP) fomesafen (Reflex) flumioxazin (Chateau1) linuron (Linex /Lorox1) pyroxasulfone (Zidua) sulfentrazone1 Sulfentrazone MTZ1 (pre-mix of sulfentrazone and metribuzin); Sencor STZ1,2 (co-pack of metribuzin and sulfentrazone sold in Canada)	EPTC (Eptam) S-metolachlor (Dual Magnum/Dual II Magnum) metolachlor (Me-too-Lachlor) pendimethalin (Prowl H2O, Prowl 3.3EC) trifluralin (Treflan HFP) S-metolachlor + metribuzin (pre-mix) (Boundary)	rimsulfuron (Matrix, labeled as Prism in Canada) metribuzin (TriCor )	rimsulfuron (Prism) Only for use in Canada and only postemergence metribuzin + rimsulfuron (co-pack) (Titus Pro) Only for use in Canada ONLY FOR EMERGED GRASSES sethoxydim (Poast Plus/Poast Ultra) clethodim (Select) fluazifop- p-butyl (Venture2) Only for use in Canada

Both U.S. and Canadian trade names are shown.

Herbicide Timing Program can be Preemergence (PRE) only, PRE + Postemergence (POST), or POST only.

1 These herbicides also have foliar activity and can control emerged weeds but MUST be applied before potato emergence.

2 Labeled for use only in Canada.

3 Some of these herbicides may be applied sequentially: preemergence + postemergence or postemergence + postemergence. Follow the label for your area.

NOTE: Information for Preplant/Preplant incorporated timing and end-of-season vine kill herbicides is in the labeled sections below but not included in this table due to space constraints.