Fungicide Buyers' Guide

Published online: Mar 11, 2022 Articles, Fungicide, New Products
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This buyers' guide appears in the March 2022 issue of Potato Grower.

Black dot. Late blight. Fusarium wilt. Ugly names attached to truly ugly diseases with the potential to completely wreck an entire potato crop.

Over the years, growers, researchers and chemical reps have worked tirelessly to develop sustainable, economical solutions to the problems posed by these fungal maladies. Here, we showcase a few of those solutions.

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.

Vive Crop Protection

(888) 760-0187


AZterknot is the industry’s first three-way fungicide that combines the benefits of a biological with the performance of chemistry and the ease of Allosperse technology. It delivers systemic, broad-spectrum, preventative control of key diseases; induces the plant’s natural defenses to improve plant health and increase stress tolerance; and improves quality and yield.

AZterknot contains two powerful modes of action—Group 11 and Group P5—making for smart resistance management. It also mixes well with liquid fertilizers, hard water and other crop inputs, even in low-volume solutions.

AZterknot contains azoxystrobin and Reynoutria sachalinensis extract, as well as the Allosperse nano-polymer delivery technology. Delivering ground-breaking disease control, AZterknot promotes better plant health and greater ROI.


Huma Gro

(480) 970-7525


Huma Gro Promax is a broad-spectrum, soil-applied fungicide and nematicide used as a preventive and curative agent. OMRI-listed and EPA-exempt, Promax can be applied at any point in the growing season. It doesn’t keep growers out of the field and is not harmful to roots. Promax has no restricted use and no buffer zones, re-entry intervals or residues. It’s compatible with most other inputs, so it’s an ideal product for tank-mix strategies and rotation programs.

With Promax, growers are working toward the long term and not burning out soil for quick results. When a program is implemented that combines Huma Gro Zap seven to 10 days after the final Promax treatment, a beneficial soil biology is stimulated that will sustain fields for future crops.

Proud 3

Huma Gro Proud 3 is an organic-listed crop protection product. It is a safe and effective, foliar-applied insecticide, miticide and fungicide. The mode of action is as a contact killer. As an insecticide, it works best on soft-bodied insects or on juveniles.

Other benefits include:

    • Directly affects soft-bodied insects and mites
    • Provides excellent control against fungal/bacterial diseases in crops
    • Activates natural defense mechanisms in plants 
    • Offers proven control of some human pathogens found on crops
    • Safe for crops, humans and the environment
    • Fungicidal effect against all types of fungal spores
    • Natural chemistry has no documented cross-resistance
    • Zero-day REI
    • Zero-day pre-harvest interval

Oro Agri

(559) 442-4996


PREV-AM is a three-in-one insecticide, fungicide and miticide. It is a contact pesticide that can be applied throughout the season without danger of resistance buildup, and is perfect for controlling pre-harvest insect and disease infestations. With a short REI and PHI, PREV-AM is a versatile alternative to conventional pesticides and is ideal for IPM and sustainable farming practices.

As a fungicide, the PREV-AM spray solution breaks down the protective membranes of the superficial fungal mycelia (hyphae) and spores, allowing the active ingredient to penetrate and destroy the living tissues underneath. This exposes the organism to the drying effect of the atmosphere and causes collapse within two to 24 hours. Plant tissue damaged by the fungus may also dry out and prevent further spread of infection, but healthy tissue is not affected at the recommended application rate.




Potato growers facing post-harvest diseases now have a new option for protection during storage: Archive fungicide from Syngenta.

“Archive is a powerful pre-mix fungicide that will help growers combat the major storage pathogens that threaten their crop,” says Heather Ambuehl, post-harvest lead at Syngenta. “This post-harvest tool is one growers can incorporate into their decay management strategy.”  

This broad-spectrum fungicide, now registered for use in potatoes, combines two unique modes of action for more broad-spectrum disease control and built-in resistance management. Fludioxonil and azoxystrobin fungicides deliver proven, robust protection against silver scurf and Fusarium dry rot—pathogens that are of particular concern while potatoes are in storage.

Fludioxonil (FRAC Group 12) is a phenylpyrrole fungicide that provides proven control of some of the most difficult-to-treat storage diseases, such as Fusarium dry rot. Azoxystrobin, a Qol fungicide (FRAC 11), effective against all four classes of fungi, brings another mode of action against Fusarium and provides control of silver scurf.

Orondis Gold

In potatoes, cucurbit and fruiting vegetables and tobacco, Orondis Gold fungicide combines two powerful active ingredients to deliver preventive, residual and systemic activity that aids growers in hitting a home run against diseases. It is a game-changer against oomycete diseases, protecting crops to maximize marketable yields.

Orondis Gold offers the proven, trusted performance of mefenoxam (FRAC group 4) with oxathiapiprolin, which brings a paradigm shift in active ingredient use rate compared to other fungicides. Orondis Gold is recommended for use in-furrow at planting to defend against pink rot and Pythium link through the growing season and into storage, helping protect an entire harvest and a grower’s bottom line. In addition to high intrinsic activity, oxathiapiprolin has a novel mode of action and is not cross-resistant to any other fungicide.


(888) 462-6822

Blocker 4F

Blocker 4F is an important foundation fungicide that suppresses persistent diseases in potatoes, such as stem canker/black scurf, white mold, black dot and others. Blocker 4F blocks the progression of disease by inhibiting lipid and membrane synthesis of the fungi and halting the sporulation process. By using this unique mode of action, Blocker 4F prevents the disease from infecting your crop. It can be applied via chemigation, allowing growers to get better performance from applications of other fungicides, while helping preserve their usefulness within a resistance management program.


EQUUS 720 SST fungicide is a cornerstone in disease management programs for potato growers fighting black dot, Botrytis vine rot, early blight or late blight. As a Group M5 foundation fungicide, EQUUS provides excellent activity on these diseases and can be applied alone or in a tank mix with other registered fungicides. With excellent crop safety and multi-site modes of action, potato growers will achieve the best results when using EQUUS as part of a disease program based on pest pressure and plant size.

UPL North America

(610) 491-2800

Dexter Max

Dexter Max fungicide controls key diseases with the potential for enhancing yield in key crops, including potato. Dexter Max provides both contact and systemic activity, and two modes of action make it a great fit for resistance management programs. Key potato diseases controlled by Dexter Max include black dot, early blight, late blight, grey mold and powdery mildew.

Bayer Crop Science

Emesto Silver

Backed by a century of potato expertise, Emesto Silver is an innovative potato seed treatment fungicide that controls seed- and soil-borne disease and promotes early crop establishment and plant vigor. Featuring a new class of chemistry, Emesto Silver fights Rhizoctonia, Fusarium and Helminthosporium silver scurf, as well as black scurf, stem canker and stolon canker, promoting higher yields and aiding business success.

Luna Tranquility

Luna Tranquility protects potatoes throughout the growing season, improving plant health for beautiful crops and abundant yields. As a breakthrough systemic fungicide, Luna provides unparalleled control of white mold, early blight and other problematic diseases. It effectively controls all labeled diseases even when applied with chemigation equipment, and offers an excellent rotational fit with other available fungicides for resistance management.

Serenade ASO

Serenade ASO fungicide is a powerful tool designed to protect against the effects of soil and foliar bacterial and fungal diseases. Applied at planting or through chemigation, Serenade ASO quickly builds a disease-protection zone around the seed or transplant. Applied as a foliar spray, Serenade ASO protects crops against diseases; both applications result in higher yields.

Serenade ASO directly attacks diseases in the soil including Pythium, Rhizoctonia, Fusarium and some strains of Phytophthora. It activates natural plant defenses by priming systemic responses, and can be used in programs with other fungicides to help prevent the development of fungicide resistance.

Summit Agro USA

(984) 260-0407


Potato growers now have access to a first-of-its-kind hybrid fungicide, Regev. This is the first product to combine the disease control activity of a botanical ingredient (tea tree oil) with a conventional fungicide (difenoconazole).

Regev controls a broad range of diseases in potatoes including early blight, brown spot, white mold, black dot and gray mold. It even controls bacterial diseases such as leaf spot and soft rot.

A primary advantage of Regev is that it has two active ingredients but only one residue. One mode of action works by cell membrane disruption (FRAC Group 46) while the other MOA affects sterol biosynthesis in membranes (FRAC Group 3). Having these two modes of action provides REGEV with its high efficacy against a wide range of plant diseases.

The natural botanical ingredient in Regev—tea tree oil—delivers activity against both fungal and bacterial pathogens.



(973) 245-6000


Provysol fungicide is the first and only isopropanol azole for potatoes that provides effective and longer-lasting early blight, brown spot and black dot control due to its unique molecular structure and steady translocation, helping growers to control diseases now and for years to come. Potato growers can confidently utilize Provysol fungicide as a foundational element of their spray program and as part of a long-term strategy to maintain the yield, quality and marketability of their crops.


Trident Ag Products

(509) 731-5424

Strike Fumigants

Strike effectively suppresses pathogenic soil fungi and helps manage soil-borne parasitic nematodes, as well as other growth-inhibiting soil pests. Pre-plant soil fumigation treatment with Strik is the first step to a successful soil health and pest management system. It has shown to lead to larger tuber set, improved crop quality, better soil health, and capability for a shorter rotation.


BioSafe Systems

(888) 441-1975

OxiDate 5.0

OxiDate 5.0, known as “the disease disruptor,” destroys bacterial and fungal pathogens such as bacterial leaf spot, early blight, late blight, powdery mildew, potato brown rot and white mold on contact, helping prevent infection and immediately stopping spread of disease.

OxiDate 5.0 is a cost-effective tank mix partner that bolsters resistance management by destroying tolerant and resistant diseases. It oxidizes bacterial and fungal pathogens along with their spores on contact, and reduces spray tank PH to help improve the activity of most tank-mix partners.