In the smartphone/Wi-Fi/touchscreen/tablet/Bluetooth era, it’s tempting to think that technology requires a computer chip. But the folks in the labs, where new-and-improved chemical-control products are created, would probably beg to differ. Take today’s fungicides, for example. What might look like just a jug of liquid actually contains a significant amount of technology – and the benefits are many.
Technology and health benefits
“As an industry, we are very much challenged as far as bringing new chemistry out,” says Rob Golembiewski, green solutions specialist with Bayer CropScience. “The EPA’s environmental regulations are only getting more stringent. They have definitely tightened down. It’s becoming more and more challenging to get new fungicides registered.”
Despite these challenges, control products companies are using technology to unveil new fungicides.
For example, Golembiewski says, the industry is increasingly taking a “two-pronged” approach with fungicides designed to improve the plant’s ability to stand up to stress, so that the plant is healthier and less of the active ingredient in the fungicide is needed to suppress or control disease.
Golembiewski expects that trend to accelerate: “I think we will probably see fewer new true synthetic fungicides and maybe more blends or combinations with other additives or ingredients in those formulations that will have a positive impact on plant health and performance, and the ability to mitigate stress, and that this will optimize active ingredient or fungicide in that mix to perform,” he says. In other words, improving the plant’s ability to stand up to stress will make it healthier, so that less fungicide is needed to suppress or control disease.
An example of a fungicide that incorporates these added plant health benefits is Bayer’s newly introduced Signature XTRA StressGard, which uses an existing active ingredient (fosetyl-Al) in a new formulation that’s designed to “enhance plant health and turf quality, while minimizing stress from both abiotic and biotic sources.”
The advent of more extreme weather patterns is, to an extent, behind the development of these new fungicide technologies, says Syngenta technical manager Dr. Lane Tredway.
“One of the newer trends in crop protection is to look not only at the disease control properties of a fungicide, but to also examine the physiology of the plant and [its ability to] withstand heat and/or drought stress,” Tredway says. The prospect of continued climate change and limited water availability, etc., is leading manufacturers to look for ways that fungicides might be able to help the turf, even beyond protecting it from disease.
Tredway doesn’t like using the term “plant health” to describe additional products/benefits that might be incorporated into fungicides. He points out that improving plant health is the whole purpose of applying a fungicide.
“By definition, if the plant is diseased, it’s not healthy,” he explains. “I look at it more as managing key stresses: Disease is a key stress, heat is a key stress, drought is a key stress, etc. The goal is to benefit the plant, not only in controlling the [fungal] pathogen, but in other ways, as well.”
As one example, he cites acibenzolar, a “plant defense activator” that’s an ingredient in some Syngenta fungicides. “It controls certain diseases like anthracnose, and certain pythium diseases, but…we’ve also discovered some very exciting effects in also dramatically improving the plant’s tolerance to these key abiotic stresses,” he explains.
Another example of a product designed to promote plant health beyond controlling disease is BASF’s Lexicon, a broad-spectrum product designed to provide a variety of plant health benefits, such as increased photosynthesis, stronger roots and improved turf vitality.
Colleen Tocci, marketing manager with Engage Agro, points out that there are also alternative natural and biological fungicidal technologies that address disease pressure by improving overall plant health.
“Technologies with modes of action such as SAR (Systemic Acquired Resistance) and ISR (Induced Systemic Resistance) help stimulate the plant’s natural defense mechanisms, essentially helping the plant to defend itself against the pathogen; thereby reducing the plants susceptibility to the disease in the first place,” she explains.
A broad approach
“Golf course superintendents want broad-spectrum fungicides, and they always have,” says Tredway. “If you go back to some of the earliest fungicides ever used, they were very broad spectrum – almost to the point where a superintendent really didn’t have to think about what disease they were trying to control.”
But with the Environmental Protection Agency (EPA) setting high standards for safety and environmental impacts, it’s become necessary to identify chemicals that are targeted at specific organisms. “In doing so, you inherently make the chemical more narrow-spectrum. Over the last 20 years, the trend is that products have become less broad-spectrum,” says Tredway.
One of the goals, he says, has been to find new technologies – like Syngenta’s recently released Velista – that “have minimal impacts on non-target organisms and the environment, while still being broad spectrum.”
Velista is a broad-spectrum fungicide in the SDHI class of chemistry, explains Tredway. The SDHI family is an older class of chemicals – in use back to the 1960s.
“What’s changed is that we’ve been able to apply modern chemical engineering techniques to optimize this chemistry to ensure that it’s absorbed into the plants more efficiently; that it penetrates into the fungal cell more efficiently; and that it binds to the target site within the fungal cell as efficiently as possible,” he explains.
If this sounds like the description of a modern drug advancement, it’s not a coincidence; Tredway says it’s the first time that “pharmaceutical design techniques” have been applied to a crop protection chemical.
Another way that some new fungicides offer broader control is by combining products. FMC Professional Solutions’ recently introduced Fame +T is one example.
“It’s a new combination product for us,” explains Bobby Walls, product development manager for FMC. He notes that the product uses a newer generation of fluoxastrobin together with tebuconazole, which has been around for some time. The combination of these two existing classes of chemistry results in a very broad-spectrum fungicide, says Walls.
He says that broad-spectrum control was a goal in the development of this new product, in part because weather patterns are constantly changing, and disease patterns can change with them.
“In some evaluations this year working with some of the major pathologists at key universities, some were reporting different diseases that they hadn’t seen in a couple of years,” Walls notes. “That’s why I think it’s helpful to look at some of the broader-spectrum products; you may know you have dollar spot and brown patch, or maybe anthracnose, depending on where you are. But you might also see another patch or spot disease that might spring up; if you have a broader-spectrum product, hopefully you can catch some of those.”
Technology and the environment
“I would say that a majority of turf fungicides currently offer a high level of safety to the terrestrial golf environment,” emphasizes Rick Fletcher, technical services manager with Nufarm. “The systemics and local penetrants have plant absorption within four to 48 hours, removing them from further environmental participation, and the barrier protectant products have fairly rapid dissipation, most less than 14 days, which also eliminate them from long-term environmental exposures.”
One key area where technology has been able to further reduce the environmental impact of fungicides is through the introduction of products that can be used at dramatically lower rates than past fungicides. BASF’s Xzemplar (a narrow-spectrum product specifically designed to target dollar spot), for example, was designed to be effective at extremely low rates, says Kyle Miller, senior technical specialist with BASF Professional Turf & Ornamentals.
“One of the things that we’ve been able to do with some of this new technology is that the rates are now down in the two-tenths of an ounce per 1,000 square feet, compared to the days when you had to use products at 1, 2, 3, 4, even up to 8 or 10 ounces,” he explains. “That means there is less impact on the environment.” And, he notes, the EPA is requiring low toxicity, so low use rates are important – a trend he thinks will continue.
“We used to be talking about putting out pounds on the ground; now we’re talking about ounces. It takes less material to do that job,” agrees FMC’s Walls. In part that has to do with new chemistries and new formulations, but it also has to do with advances in application technologies, like spray nozzles, he notes.
“And I think we’re improving our scouting and modeling for when we apply fungicides, because proper timing is key with any product,” Walls says. “If you put it out at the optimum time, you get better control.”
There also are alternatives to synthetic fungicides. “Fungicide technologies containing natural, biological ingredients such as microbials, plant extracts and mineral oils, have contributed to environmentally safer products,” says Tocci with Engage Agro. “Products combining different active ingredients; conventional technologies along with ingredients that are known to be more ‘environmentally friendly’ are also now available, offering more sustainable solutions to turf managers.”
Natural and biological fungicide technologies do not necessarily work longer, says Tocci. But she states that “use of these technologies encourage overall plant health and reduced disease incidence, thereby reducing the amount of chemicals required. In addition, many of these products have little to no known resistance, unlike many conventional products.”
Longer lasting?
One area where it’s been particularly tricky to develop new fungicide technologies – and that researchers continue to explore – has to do with the length of time that the product works.
“The EPA doesn’t really want something that hangs around in the environment too terribly long,” says Miller with BASF. “Any superintendent would love for something to last a long time, but I don’t think that’s going to be an easy thing to hit on.”
“I don’t think we’re necessarily seeing an increase in the duration of control,” agrees Tredway, citing both regulator and practical limitations. “With the environmental impact standards that we all operate under, long residual is generally a bad thing. We’re also dealing with a turfgrass plant that’s constantly growing and constantly being mowed, and therefore the products that are applied are constantly being harvested – so there’s always a limit to how long a product can last.”
Making fungicide products last longer is not always the correct answer anyhow, says Fletcher with Nufarm: “The better question is, ‘Can I have the product in the right location, in the right dose, at the right time for my disease control needs?'”
He explains that both root and foliar diseases present limitations as far as designing products that can be effective for long durations. “For foliar, we must account for plant growth and chemical movement in the equation,” Fletcher notes. “Turf plant leaves develop from bud to maturity and death in a predictable 21- to 28-day cycle. Barrier-protectant formulations often do not allow for relocation of product to newly products leaf areas.” And the duration of a product for root diseases depends on both its solubility and soil adhesion “to ensure a balance between root availability and soil stability.”
Miller says that future fungicides might use micro-encapsulated technologies in order to envelop the active ingredient and release it slowly over time, the same way that some herbicides and fertilizers do today. But Miller says the very nature of fungicides/turf diseases poses special challenges to this approach, too. “It’s hard to get good, even release of the product; you don’t want to have something out there that’s not releasing and you need it to release because it’s dry and you’re not getting disease prevention. But maybe someday that technology will get perfected.”
Other factors affecting fungicides
Many of the advances in the effectiveness of fungicides, and their ability to work at lower rates, is due to work in the lab by control product manufacturers. “But beyond what we do, there have been a lot of other advances in spray equipment, spray nozzles and spray adjuvants,” says Syngenta technical manager Dr. Lane Tredway. He points out that getting the best results from new fungicide technologies also depends on their proper use. It’s up to the superintendent to be sure fungicide products are applied accurately and uniformly; to make sure the product is actually applied on the leaf surface or other target; and that drift and movement of the material off-site is minimized, he stresses.
Essentially, all of the technology that’s been developed in the lab can be rendered useless if it’s incorrectly applied out in the field.
“Thanks to our university turf pathologists, we have such a better understanding of fungal organisms. We understand that, even if we see a certain disease express itself in the summertime, it actually starts from a life cycle in the springtime,” adds Rob Golembiewski with Bayer. “So if we can better time our applications to when that organism is just starting to become active, we can actually decrease our fungicide inputs over a year’s time.”
Improved cultural practices — proper mowing heights, topdressing, verticutting and fertilizing — also are critical in ensuring the best results with fungicide applications.
These practices can not only can reduce the incidence of disease, but maximize the fungicide’s performance when it does get used, says Golembiewski.
The cost of technology
As with any other new technology, today’s advanced fungicides tend to carry a premium over older products on the market. In part, that’s because of factors beyond the control of product manufacturers.
“To bring a new product (to market) is just more and more expensive,” says BASF’s Miller. What used to cost $100 million now costs $300 million. “The EPA requires more studies than they did in the past. As a rule, I think it’s going to cost a little bit more for the new technology.”
Prices of new, high-tech fungicides may seem higher than older products, says FMC’s Walls. But, given the lower rates that many new fungicides can be applied at, he says, it’s important to compare application costs rather than product costs: “You might only have to put 5 ounces into your sprayer, whereas you might have needed two containers of a product in the past.”
One way to keep costs down is to use a rotation of conventional chemistries, in conjunction with some of the newer biologicals, suggests Tocci with Engage Agro: “This helps reduce the overall program cost while reducing disease resistance potentials with alternating modes of action.”
And Bayer’s Golembiewski makes the point that part of the cost of new fungicides, at least with non-generic products, represents that manufacturer’s investment in the design of future products – the next generation of fungicide technology.
White, a freelance writer based in Middlesex, Vermont, has spent several years working in golf maintenance, and over the past several years has served as an editor and writer for numerous regional and national golf publications.
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