New Chemistry to Fight Early Blight in Potatoes

Provysol Fungicide  

For potato growers battling early blight, brown spot and black dot, BASF has introduced a revolutionary new disease management tool. Provysol fungicide is the first and only isopropanol azole fungicide, making it a truly unique solution for disease control. Provysol fungicide not only controls key diseases, but also provides a new mode of action to manage resistance and has excellent tank-mixing capabilities.


The uniqueness of the product lies in the innovative molecular structure of Revysol® fungicide, the active ingredient in Provysol fungicide. Curtis Rainbolt, BASF Technical Service Representative, speaks to how it works: “The unique isopropanol azole bridge allows the Revysol molecule to customize its shape for tighter binding at the enzyme site of action for excellent efficacy of even the toughest diseases.” Used as a foundational tool, it can strengthen the overall spray program and reduce risk of resistance development.


Rainbolt shares that Provysol fungicide controls important foliar diseases, including Alternaria, brown spot and black dot. “These are diseases that, at least in Idaho, we can find in pretty much every field.”


Rainbolt explains, “Provysol fungicide is really delivering a level of performance that we haven’t seen in a while. In addition to the high level of control, there is a long duration of control and it tank-mixes well with a lot of other products that growers might use on their fields, so it’s really got a nice all-around fit.”


To determine control of disease pressure from Provysol fungicide, Dr. Jeff Miller, owner and operator of Miller Research LLC, out of Rupert, Idaho, tested Provysol fungicide on his research farm.

Dr. Jeff Miller, owner and operator of Miller Research LLC, discusses trials done on his research farm in Rupert, Idaho, to determine control of disease pressure from Provysol fungicide.

Field Trial Results

Miller Research has been testing Provysol fungicide for several years with positive results. Dr. Miller shared his experience with the product during a BASF field day in August. “We first began testing Provysol fungicide several years ago, and it has been very impressive from the start. There’s only been a few products that have come along that have been very effective at almost eliminating early blight. Provysol fungicide is in that category.”


Provysol Fungicide Spray Timing

Provided such use is permitted by the relevant label, Dr. Miller recommends that fungicides be used preventatively, not as a rescue or a curative treatment. Because of that, Dr. Miller recommends incorporating Provysol fungicide in the early part of the grower’s program with “two applications around row closure to two weeks later,” noting that, “When you look at the level of protection you get from an early application, versus late, you get so much superior disease control, and you have much less blight later on.”


Provysol for Resistance Management

Dr. Miller is concerned that while growers may be rotating products, that does not necessarily mean they are rotating between Fungicide Resistance Action Committee (FRAC) groups, which can lead to resistance.


The SDHI fungicides, which are members of FRAC Group 7, are critical components of many potato growers’ disease management strategy. Recently, there has been a push to use SDHI fungicides not only as foliar treatments for managing white mold and early blight, but also in-furrow and early in the plant’s growth cycle, when plants are six to eight inches tall, to target nematodes.


In speaking about his experience, Dr. Miller shared, “Where I’m using a Group 7 in the furrow, I want to minimize the amount of times that I would put it on the foliage now. So, if I have a different group, a Group 3 fungicide like Provysol fungicide, it would be a perfect fit now to put that in the early part of your fungicide program.”


“With Provysol fungicide we have a triazole, which is in a completely different category of fungicide, which has high efficacy. Now growers have something that they can rotate to, so they don’t have to use the same FRAC groups. They can use Provysol fungicide, which should extend the life of all the fungicides involved, not only Provysol fungicide, but the other chemistries as well,” he added.


As a closing thought, Dr. Miller shared, “When we get access to a really high-quality product, such as Provysol fungicide, we want to make it last as long as we can. We can practice good stewardship principles, and we’ll still get great control.”


For more information, connect with your local BASF representative.


Always read and follow label instructions.


Provysol fungicide is a trademark and Revysol fungicide is a registered trademark of BASF.


About BASF’s Agricultural Solutions division
With a rapidly growing population, the world is increasingly dependent on our ability to develop and maintain sustainable agriculture and healthy environments. Working with farmers, agricultural professionals, pest management experts and others, it is our role to help make this possible. That’s why we invest in a strong R&D pipeline and broad portfolio, including seeds and traits, chemical and biological crop protection, soil management, plant health, pest control and digital farming. With expert teams in the lab, field, office and in production, we connect innovative thinking and down-to-earth action to create real world ideas that work — for farmers, society and the planet. In 2018, our division generated sales of €6.2 billion. For more information, please visit or any of our social media channels.


About BASF
At BASF, we create chemistry for a sustainable future. We combine economic success with environmental protection and social responsibility. The approximately 122,000 employees in the BASF Group work on contributing to the success of our customers in nearly all sectors and almost every country in the world. Our portfolio is organized into six segments: Chemicals, Materials, Industrial Solutions, Surface Technologies, Nutrition & Care and Agricultural Solutions. BASF generated sales of around €63 billion in 2018. BASF shares are traded on the stock exchange in Frankfurt (BAS) and as American Depositary Receipts (BASFY) in the U.S. Further information at