EPTC (Eptam 7E or several trade names, 7 lb ai/gal)
Soil active, only
Rate 3.5 to 7 pints/A (3 to 6 lb ai/A)
Time Preplant: preplant incorporated or preemergence. When applied after planting apply and immediately incorporate into soil before planting potatoes. Preemergence: after a clean cultivation (hilling).
Remarks If applied preplant, thoroughly incorporate into soil immediately after applying 2 to 3 inches deep by cross-disking 4 to 6 inches deep or by tilling with a power-driven rotary tiller cutting 2 to 3 inches deep.
If applied after planting, incorporate either mechanically into the top 2 to 3 inches of soil or by sprinkler irrigation. See previous entries in this section for application and incorporation methods, remarks, cautions, re-cropping and rotational cropping restrictions, and site of action and chemical family information for this herbicide.
Site of action Group 8: lipid synthesis inhibitor but not an ACCase inhibitor
Chemical family Thiocarbamate
Paraquat (SL or Inteon, 2 lb paraquat cation/gal; Firestorm, 3 lb paraquat cation/gal; or several trade names or glyphosate (various formulations and trade names)
Foliar active, only
Rate Apply to fallow ground before planting potatoes: 1.5 to 4 pints/A Gramoxone SL or Inteon (0.75 to 1 lb ae/A).
After planting and before potatoes emerge: 1 to 2 pints Gramoxone SL or Inteon (0.5 to 1 lb ae/A) or 1.3 pints/A (0.49 lb ae/A) Firestorm + a nonionic surfactant with 75% or more surface-active agent at 0.125% v/v (1 pint/100 gal spray mix) or crop oil concentrate at 1% v/v (1 gal/100 gal spray mix) for ground applications or 1 pint/A for aerial applications.
Timing After planting and before potatoes emerge - glyphosate at 0.38 lb ae/A.
Remarks These herbicides control only wild oat emerged at the time of application. Wild oat emerging later will not be controlled. Some glyphosate formulations require nonionic surfactant (NIS) ; see label for details. Adding 1 to 2% dry ammonium sulfate (AMS) by weight or 8.5 to 17 lb/100 gal spray-mix may increase performance. The equivalent rate of AMS in a liquid formulation also may be used.
Caution Restricted use pesticide due to acute toxicity. For retail sale to and use only by certified applicators - not to be used by uncertified persons working under the supervision of a certified applicator. Do not apply either paraquat or glyphosate if potatoes have emerged, because crop may be injured. See previous entries in this section for application and incorporation methods, remarks, cautions, re-cropping and rotational cropping restrictions, and site of action and chemical family information for this herbicide.
Site of action paraquat - Group 22: photosystem 1 electron diversion; glyphosate - Group 9: inhibits EPSP synthase
Chemical family (paraquat) bipyridilium; (glyphosate) none generally accepted
rimsulfuron (Matrix SG; Matrix FNV; Solida; or several trade names, 25%)
Soil and foliar active
Rate 1 to 1.5 oz/A (0.0156 to 0.023 lb ai/A rimsulfuron + nonionic surfactant (NIS) at 0.125% to 0.25% v/v (1 to 2 pints/100 gal spray solution) or 1% v/v (1 gal/100 gal spray solution) crop oil concentrate or methylated seed oil (MSO) if wild oat are emerged.
Time Preemergence after hilling or dragoff but before potatoes and wild oat emerge or postemergence to wild oat in the two- to four-leaf stage (3 to 5 inches tall).
Remarks See previous entries in this section for application and incorporation methods, tank mixtures, remarks, cautions, re-cropping and rotational cropping restrictions information for this herbicide.
Caution Applied postemergence, rimsulfuron may temporarily yellow potato foliage. Under environmental stress (cool, wet, or hot or humid weather), rimsulfuron applied postemergence also may stunt growth and cause leaf malformations. Potatoes recover within 7 to 15 days. To reduce potential injury, apply only if the weather has been sunny for at least 3 successive days. Do not use on seed potatoes unless permitted by a supplemental label.
Site of action Group 2: acetolactate synthase (ALS) inhibitor
Chemical family Sulfonylurea
sethoxydim (Poast or several trade names 1.5 lb ai/gal; Poast Plus or several trade names, 1 lb ai/gal)
Foliar active, only
Rate 1.5 pints/A of the 1.5 lb ai/gal; or 2.25 pints/A of the 1.0 lb ai/gal formulation (0.28 lb ai/A)
Time Apply to actively growing wild oat up to 4 inches tall.
Remarks Always add a nonphytotoxic oil concentrate to the spray tank at 2 pints/A or methylated seed oil at 20 oz/A or Dash HC at 16 oz/A. Depending on the crop, the addition of ammonium nitrate or ammonium sulfate is recommended. Sethoxydim can only be tank mixed with metribuzin in potatoes.
Caution Control may be erratic on grasses stressed by drought, temperature extremes, insect damage, herbicide injury, and other factors. Do not apply if rain is expected within 1 hour after applying. Do not cultivate within 5 days before or 7 days after applying. Preharvest interval is 30 days. See previous entries in this section for application and incorporation methods, remarks, cautions, re-cropping and rotational cropping restrictions specific to this herbicide.
Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family Cyclohexanedione