Herbicide Buyers' Guide

Published online: Mar 26, 2021 Herbicide, New Products
Viewed 3486 time(s)
This buyers' guide appears in the April 2021 issue of Potato Grower.

Since the day Adam and Eve left Eden, farmers have had to contend with weeds encroaching on their crops’ territory and robbing their precious resources. These days, weeds are smarter than ever, always finding new ways to fight back. With the help of the products in our buyers’ guide, you can keep those pesky plant pests at bay.

Always read and follow label instructions. Some products may not be registered for sale or use in all states or counties. Please check with your state or local extension service to ensure registration status.

Gowan Company

(800) 883-1844


Eptam 7E Selective Herbicide

Eptam 7E is a long-trusted selective herbicide used in potatoes, dry beans, alfalfa and other crops. Where other pre-plant herbicides can reduce your yield, Eptam 7E’s superior crop safety gives you the security to know you’ll get the best yield potential from your potato acres. It has excellent plant-back timing (45 days maximum), so growers have no rotation worries next year.

Eptam 7E has excellent control on annual grasses and key annual broadleaf weeds like hairy nightshade, pigweed, common lambsquarters and some perennial weeds like sedges. 

When incorporated, Eptam 7E forms a barrier in the soil, which disrupts seedling shoot development by inhibiting lipid synthesis and preventing emergence. Weeds that do emerge are weakened and more susceptible to post-emergence chemistries.

Eptam’s application flexibility allows for use as a pre-plant incorporated, post-plant incorporated, or post-emergence layby treatment to control the weed seed bank before they emerge. It can be applied as a ground spray or through chemigation.

Eptam 7E, Group 8, brings a different mode of action to any weed resistance management program, helping to preserve weed control options. 

Corteva Agriscience


Matrix SG

Matrix SG herbicide is an excellent choice as a “foundation” herbicide and not simply a “rescue” herbicide. Matrix is one of only two herbicides used in potatoes that have post-emergent activity (burndown) and pre-emergent activity (residual). Additionally, growers have the option to apply a second application of Matrix in-season. Matrix is also widely-used in light-skinned potato varieties (e.g., Shephody) where metribuzin is not an option.  Weeds controlled include pigweed, volunteer alfalfa, henbit, kochia, volunteer cereals, shepherd’s purse, mustards, chickweed and bedstraw.  Matrix SG can be applied by ground, air and chemigation.

Oro Agri

(559) 442-4996


ORO-RZ Soil Adjuvant

ORO-RZ adjuvant improves the efficacy of soil-applied, pre-emergent herbicides while contributing to better soil health. ORO-RZ improves soil hydraulic conductivity, even in hydroscopic soils, to move the herbicide solution into soil pore spaces.

This lowering of hydraulic conductivity and movement into pore spaces helps lay down a uniform barrier in the top few inches of the soil, where most weeds germinate. Because of the low surface tension of ORO-RZ, the herbicide spreads uniformly, eliminating coverage gaps so germinating weed can’t emerge through the blanket of herbicide protection.

ORO-RZ also contributes to soil health. It has very low surface tension, so it flows within the micropores in the soil, leading to better aeration and water penetration. ORO-RZ even helps penetrate and break up pockets of hydrophobic soil. These improvements to aeration and soil structure encourage microbial and adventitious root growth and, ultimately, a healthier soil environment.

Wetcit Foliar Adjuvant

Wetcit, now with TransPhloem technology, is a foliar adjuvant with great benefits for potato growers from pre-plant to harvest. Used at lower rates, it is an excellent spreader for contact herbicides. Used at higher rates, Wetcit is a superior penetrant that delivers herbicide active ingredients to target sites within weeds, more quickly and in higher concentrations compared to other adjuvants such as crop oils, methylated seed oils, high-surfactant methylated seed oils and non-ionic surfactants. This means Wetcit improves the speed and efficacy of systemic herbicides like Roundup compared to these other types of adjuvants.

Come harvest time, using Wetcit with a desiccant will help ensure a great vine kill to improve potato quality and aid in harvesting. The superior performance of Wetcit with contact or systemic pesticides simplifies choosing the right adjuvant for the job and eliminates the need to have several adjuvant products on hand.


(866) 796-4368


Boundary 6.5 EC

With a combination of the active ingredient metribuzin and Dual Magnum herbicide, Boundary 6.5 EC herbicide delivers hard-hitting pre-emergence control plus long-lasting residual control to keep grass and broadleaf weeds out after potato emergence.

Dual Magnum

Recommended as a pre-plant surface-applied, pre-plant incorporated or pre-emergence application, Dual Magnum herbicide is powerful chemistry that provides excellent control of grasses, nutsedge and small-seeded broadleaf weeds.

Gramoxone SL 2.0

With fast-acting results in as little as 48 hours, Gramoxone SL 2.0 delivers convenient, flexible and dependable burndown of emerged grass and broadleaf weeds. Effective under a variety of conditions, it targets the most difficult-to-control weeds.

Gramoxone SL 3.0

Formulated for optimum efficiency, the increased active ingredient load of Gramoxone SL 3.0 leads to lower application volumes and reduced handling. Backed by knowledgeable Syngenta field sales representatives and agronomists, Gramoxone SL 3.0 provides trusted brand performance against tough grasses and broadleaf weeds.


With fast, effective and long-lasting residual activity, Reflex offers pre- and post-emergence control of a broad spectrum of broadleaf weeds and suppression of yellow nutsedge in potato.


By eliminating troublesome vines and weeds, Reglone allows potatoes to develop a firm skin set, protecting harvest quality for optimal yield. With its flexible application methods, Reglone allows for a more efficient harvest through both conventional ground and aerial sprayers and doesn’t leave harmful soil residues behind.


(973) 245-6000



Outlook herbicide provides potato growers with powerful, consistent control of grasses and small-seeded broadleaf weeds that can impact their crop. The pre-emergent herbicide should be applied between planting and crop emergence to reduce early-season competition and ensure the potato crop gets off to a strong start. Applications before weeds germinate can control a wide spectrum of weed species, including nightshades, lambsquarters, pigweeds and many others.

Aside from providing residual control of weeds, Outlook herbicide also binds more tightly to the soil to minimize leaching, even under the wettest conditions. Additionally, Outlook washes off residue more readily in all tillage systems.

Westbridge Agricultural Products

(800) 876-2767



SUPPRESS Herbicide EC is a safe and highly effective tool for organic and conventional weed management programs. It is registered as a broad-spectrum contact herbicide for post-emergent, non-selective weed control for use in and around all crops. SUPPRESS is also approved as a desiccant and harvest aid in potatoes. Westbridge’s patented formulation is a non-volatile, emulsifiable concentrate that is OMRI- and WSDA-approved for use in certified organic food production.

With nine years of grower-proven efficacy, SUPPRESS consistently provides fast and effective burndown in a wide variety of weeds. It is also an excellent tool to rotate with conventional herbicides to minimize resistance. SUPPRESS is low-foaming, easy to use, and has no pre-harvest interval so it can be applied up to the day of harvest.



Aim EC

Aim EC herbicide from FMC targets leaves and stems for complete potato desiccation. The herbicide should be applied as a foliar to potatoes in the later stages of senescence for desiccation of foliage and vines. Aim EC herbicide also desiccates late-season susceptible broadleaf weeds (including kochia, lambsquarters, nightshade and more) to aid tuber harvest.


(720) 306-6340


Efficax Adjuvant

Efficax is a soil retention adjuvant that helps growers’ spray applications last longer by increasing the coverage, absorption and adhesion of the spray material deposits onto soil particles. This also improves the residual activity of most soil-applied herbicides, ensuring growers get the full benefit of products they’ve purchased for their fields.

Efficax can improve control of early-season weeds by getting more herbicide on target, holding it in place longer, and ensuring herbicide investments are more efficient than ever. Efficax also has excellent tank-mix compatibility and can be used with most preferred herbicides.

Drexel Chemical

(901) 487-6005


Pin Dee 3.3 EC

Pin Dee 3.3 EC is a Group 3 herbicide that controls numerous grasses and broadleaf weeds, including stinging nettle. When used on potatoes, it must be incorporated or rainfall-activated within seven days. The effective mode of action controls many herbicide-resistant weeds.


Quik-Quat is a pre-plant or pre-emergence herbicide burndown herbicide that achieves rainfastness in as little as 30 minutes. With 3 pounds of Paraquat per gallon, Quik-Quat is easily tank-mixed and effective in controlling glyphosate-resistant weeds. It can be applied up to ground-cracking stage, before potatoes have emerged.

Trifluralin 4EC

Trifluralin 4EC controls numerous grasses and broadleaf weeds. It must be incorporated within 24 hours, but disrupts weeds’ growth processes during germination and has excellent tank-mixing qualities.

UPL Ltd.

(610) 491-2800



Rimon insecticide (IRAC 15) is a broad-spectrum larvicide and ovicide that provides excellent control of key pests in potatoes, including Colorado potato beetle and loopers. As an insect growth regulator, Rimon goes after eggs, larvae and nymphs while remaining easy on beneficials.

Manzate Pro-Stick

Manzate Pro-Stick fungicide (FRAC M3) is the preferred option for superior control of early and late blight. Its multi-site action reduces the risk of disease resistance, a benefit difficult to find in other fungicide options. Manzate Pro-Stick has effectively been used for decades without a reported incidence of resistance. Its advanced formulation is built to provide better coverage and adherence to the leaf surface.

Tripzin ZC

Tripzin ZC herbicide (HRAC 3,5) combines two of the most effective residual active ingredients in an innovative formulation. It is designed for pre-emergent and at-planting applications to provide consistent, long residual control of a wide weed spectrum.