Testing … 1, 2, 3

Researching new products for the turfgrass industry requires curiosity and cooperation. Sometimes the process also involves the act of finally lifting a veil.

In early June, university researchers learned the identity of three solutions they had been studying for years: Posterity XT, Posterity Forte and Ascernity. Syngenta is responsible for introducing the trio of fungicides, which offer control for diseases on cool- and warm-season turf. Their development provides insight into the methodology behind researching new products. Testing desires and procedures vary by company. Syngenta uses blind tests for new products.

“We give researchers a product with an ‘A’ number and say, ‘Please test it,’” longtime Syngenta senior technical manager Dr. Mike Agnew says. “We want to get good early data to give us an idea of how good a product is going to be in the marketplace. We do the ‘A’ number so it’s a true blind test.”

Dr. Bruce Clarke and the Rutgers team have studied Ascernity (SOLATENOL technology [benzovindiflupyr] and difenoconazole) and Posterity XT (ADEPIDYN technology [pydiflumetofen], propiconazole and azoxystrobin) since 2011 and 2017, respectively.

Dr. Jim Kerns and the NC State team have studied Ascernity and Posterity Forte over the course of multiple years. “One thing I want to reiterate,” Kerns says, “is that we had no earthly idea of what we were working with until June 1.”

What did Clarke and Kerns — along with Agnew, who helps facilitate trials — learn through the extensive testing? The trio spoke with Golf Course Industry about testing procedures and their work with the new solutions. The conversation has been edited for length and clarity.

As educators and researchers who enjoy learning, how exciting is it to test something new?

Kerns: It’s always exciting to be able to hopefully deliver new tools to turf managers. The issue when you see something is that it may not make it. But the past three or four years have been a really nice time for fungicides, because there’s a lot of new testing.

Clarke: In the late ’80s, we started seeing a reduction in the number of products available in the marketplace and a lot of people were really concerned that we wouldn’t have many products left if we didn’t see new chemistries released in the future. The companies have really put a strong effort into brining new chemistries to market. It’s exciting working with them to see what’s coming out and how it’s working into the various programs with superintendents in our area. Working in New Jersey is very similar to working in North Carolina. There are a cornucopia of diseases and perfect conditions for diseases. It’s heaven for a plant pathologist to work in an area like this.

What’s your reaction when you finally discover what you are testing?

Clarke: When you find out what a new product is and that it’s actually coming to market, that’s when I go back and intensely look at our past data. It’s quite amazing how good some of these new products are, but because they have been coded during several years of evaluation and there are so many different numbered compounds, you don’t have time to put it all together until you know that a product is actually going to be released.

What diseases did you test Posterity XT for and what did you see in those trials?

Agnew: We have tested it on several disease, including dollar spot, brown patch, summer patch and even anthracnose. Another one that’s critical from North Carolina all the way to Rhode Island is gray leaf spot.

Clarke: We focused on brown patch control and it’s outstanding for that disease. It also did exceptionally well on dollar spot and gray leaf spot, which are difficult diseases for us to control. For gray leaf spot, we usually test it on a fairly susceptible cultivar. Spores of the pathogen blow in from the south, especially when tropical storms move up the east coast. It doesn’t really overwinter here to my knowledge and It can devastate ryegrass areas.

How will Posterity XT fit into an agronomic program?

Agnew: Posterity XT is No. 1 for fairways. We need broader spectrum and long-lasting materials on fairways. It provides very good dollar spot control and is a very good Rhizoctonia material. It’s a summer application for the control of dollar spot and anthracnose. You have two active ingredients that can control dollar spot and you have one active ingredient carrying the load for brown patch. We’re also looking at it for gray leaf spot on fairways and for a summer patch application.

Clarke: The beauty of combining multiple active ingredient into one product is that it broadens the spectrum of activity for many of these diseases that occur at the same time. It not only makes it easier for a superintendent to put one product in a tank, but it helps guard against resistance issues and gives them very good control against major diseases in the summer like brown patch and dollar spot.

What have you learned in your work with Posterity Forte?

Kerns: Four or five years ago, we saw that Posterity worked really well against spring dead spot. One of the unique things with some of these new active ingredients is that the control spectrums can be unique and this one is pretty unique. When you take Posterity with dollar spot, fairy ring and spring dead spot control … nothing really links those three together all that much. We have looked at (Posterity Forte) for spring dead spot and take-all root rot and we have had it in fairy ring trials, all on ultradwarf Bermudagrass and it performed exceptionally. When we are spraying for spring dead spot, which typically happens at about a 70-degree soil temperature, we’re also hoping to get take-all root rot control on Bermudagrass. On a putting green, Posterity alone wouldn’t do that and that’s where the Forte is really going to come in handy for us down South, because we have seen very good results on take-all root rot. Agnew: Posterity Forte is unique because it contains the full rate of ADEPIDYN but a reduced rate of propiconazole to make a little bit of difference and it also contains a lower amount of azoxystrobin than Posterity XT, so it’s really geared toward those southern turf were superintendents prefer lower rates of DMI fungicides. Kerns: That’s a good point. DMI fungicides can be a no-go zone on ultradwarf Bermudagrass. We have not seen phytotoxicity with Posterity Forte. I do want to make the point all of our treatments were watered in. Even good-ole Banner (Maxx II), if it’s watered in, it’s relatively safe on the ultradwarf Bermudagrasses.

How do you view Posterity Forte fitting into an agronomic program?

Kerns: The nice thing about this is that we have found with take-all root rot that we need to start spraying in July and continue all the way into the fall. We now have multiple products that you can fit into a rotation, but the Posterity Forte can fit right at the end and give you both (control of spring dead spot and take-all root rot). When you have multiple active ingredients, it gives the consumer flexibility of where they want to put it based on the disease.

Agnew: In the North, it’s a product you can put out if you’re in a heavy dollar spot time period when brown patch happens. We have seen a lot more September and October brown patch activity. I like it sometime in the summer for northern climates, where you might get a little bit of brown patch, to those areas in the Mid-Atlantic where you get a significant amount of brown patch in that September and October period.

What have you learned in your work with Ascernity?

Clarke: We have done more work with Ascernity than the other two products. It’s a very strong dollar spot material. We have also had very good anthracnose control and those are two really big diseases for us in the Northeast and Mid-Atlantic region. We have done a little work with brown patch and had good results with that disease as well. It’s broad spectrum. The nice thing about Ascernity is that it has difenoconazole it in, which is a DMI that we haven’t seen any phytotoxicity with, which is always a concern of superintendents in hot weather. And because it has two different active ingredients, it’s good to use for resistance management.

Kerns: Ascernity was pretty new for us. It was already registered as part of a snow mold solution. We had it in a curative large patch trial this spring and it was outstanding. We have worked with the two active ingredients for a long time. We had done screening for large patch isolates because we see some really interesting dynamics that some folks have questioned and, in turn, we screened SOLATENOL and our isolates were the most sensitive to it. It is going to be a nice large patch material for us. We think of it being used on zoysiagrass fairways, but there’s more and more talk of these new elite zoysiagrass putting greens. Large patch is going to be the major issue with those and we’re going to need something to use there. The difenoconazole has been a staple on ultradwarf Bermudagrass putting greens. Part of the reason is that it’s a DMI and there’s no phytotoxicity. I suspect this is going to have one of the broadest labels for Bermudagrass because of these two active ingredients.

Agnew: It has a very broad label. There are new diseases we are finding out with it every day. With a product that has SOLATENOL and difenoconazole, I’m starting to expect the unexpected these days. We’re going to put it on a greens programs for control of summer patch, brown patch and anthracnose. It contains one of only two SDHI active ingredients on the market that can control anthracnose – the other being Velista. We also look to segment products to different areas of the golf course. It’s a heck of a product on fairways.

What we have your learned about length of control and intervals with these products?

Kerns: It depends on the disease. For something like large patch, we’re looking at a 30-day interval. For take-all root rot, people want it for 21 days to a one-month interval, but that isn’t happening. It’s going to be more of a 21-day interval. Spring dead spot is also monthly.

Clarke: Most superintendents are looking at 14 days of control with products on greens. With fairways, they would really like to get 21 to 28 days. When conditions for dollar spot are conducive, I think you’re really hard-pressed for any product to last more than 21 days. From that standpoint, Ascernity fits into a rotational spray program very well. There’s no problem getting 14-day control and, in many cases, 21-day control. In certain cases, where the weather is not conducive to dollar spot, you may get more extended control. But 14 to 21 days is pretty much what superintendents are expecting and I think that’s what they will get with this product. Agnew: The great thing about Posterity XT for fairways is that it controls over 20 diseases for up to 28 days. It is not common to get such long control of so many diseases with one product.

What is your role after a product reaches the market?

Clarke: Once a product comes to market, our work isn’t done, it’s only beginning. We get a lot of questions from superintendents about new fungicides. You have to put information about these products in perspective in comparison to current standards in the market. We have five or six years of research data from our trials before something is released. That gives us a lot of comfort in terms of being able to make a recommendation — or at least a statement — of how effective a product is under a variety of conditions. Kerns: It’s been easy to this point. Now that they have opened Pandora’s box, that means the questions will start … and rightfully so. Once superintendents learn about pricing, then there are a lot of questions. Clarke: Working at a university, we don’t have to worry about price, just efficacy. We let superintendents know how effective something is and they decide whether it can work in their budget.