Instrata (Chlorothalonil + Propiconazole + Fludioxonil)

Instrata is another fungicide that combines different active ingredients into a single product. Instrata has chlorothalonil (Daconil and many others), propiconazole (Banner MAXX and others) and fludioxonil (Medallion). Instrata quickly became the gold standard for snow mold control in northern climates like the Upper Midwest. Interestedly the formulation of this product combined suspended particles with a microemulsion that Syngenta calls a suspomicroemulsion. I really don't know what that means for golf course superintendents, but you have to admit it sounds cool! All kidding aside, we typically suggest that active ingredients should be mixed in order to achieve acceptable snow mold control. With Instrata you have three active ingredients that when combined do provided excellent snow mold control. Chlorothalonil is a contact fungicide that has activity on all three snow mold pathogens (Microdochium nivale, Typhula incarnata and Typhula ishikariensis), but is strongest on M. nivale and T. incarnata. Propiconazole is a DMI fungicide, which are known to have excellent activity on T. ishikariensis and fludioxonil seems to have activity on all three snow mold pathogens too.

For those who manage golf courses in areas that receive intense snow cover will likely experience all three snow mold pathogens at one time or another. I think the reason Instrata is a successful fungicide for snow mold control is golf course superintendents don't have to worry about predicting the weather because all the product works on all three snow mold pathogens. With respect to efficacy of Instrata, I have posted a few figures highlighting how well this product works. We do see breakthrough at our site in the UP, which has intense snow mold pressure. Yet, for the last two years we observed that 70 % of the products break down under that pressure. Even under that pressure, a single application of Instrata keeps disease severity levels between 15 and 40 %. Anyone that experiences such snow mold pressure should make two applications for snow mold and we observed that two applications of Instrata at 5.5 oz worked better than a single late application of Instrata at 11 oz at our UP site. For most golf course superintendents however, the 9.3 oz rate will work beautifully! A word of caution about the product, do not skimp on the rate in areas of high snow mold pressure. We have observed that reducing the rate to 5.5 oz in some environments may result in significant failure.

In summary, Instrata is an excellent combination fungicide for controlling snow mold diseases. It also has activity on other diseases too, which is obvious based on the active ingredients in the product. Instrata is an excellent choice for putting greens and tees and if the budget allows high value approaches and maybe even fairways. If you are interested in this product and have not used it before check out the label and Syngenta's website for more information.

Snow Mold Rating Season Has Begun!!

Whoopee! Snow mold rating season is in high gear for us. The first site we visited last week did not have a lot of activity, but our site in Stevens Point, WI was fantastic! The non-treated controls averaged 90% disease and a few products had some break through. For the most part however, most treatments did a good job preventing snow mold. We have not had a chance to enter the data and analyze it, but mixtures did exceptionally well. Products like Instrata at 9.3 oz, mixtures of Trinity/Insignia/Iprodione, Interface/PCNB, Chlorothalonil/Myclobutanil/Iprodione were just a few examples that performed exceptionally well. Interface is a new product from Bayer that will hit the marketplace some time this summer. Typically most products do well at our site in Stevens Point WI, but some of the excellent products and mixtures break down under the intense snow mold pressure at our site in Marquette, MI. We really do not know what to expect at our sites in Minnesota this year. I think both sites had substantial snow fall and cover, but one site is new and snow mold development at the other site is variable.



We do exhaustive testing of products for snow mold control and the main lesson is to combine fungicide families to achieve excellent results. Using just a single product with a single active ingredient is asking for break through. At least that is the case in the Upper Midwest. We do not have a single answer for what to apply for snow mold control because it depends on the pathogen normally observed, the courses budget and the threshold for damage. Since we do not have crystal balls to forecast the amount of snow during the winter months, combining active ingredients will ensure protection against Microdochium nivale and the two Typhula species. Combining a.i.'s usually works very well in our trials, especially those combos that are strong on ascomycetes and basidiomycetes. Pre-mixed products like Instrata and Interface usually accomplish this strategy. Chlorothalonil, propiconazole and fludioxonil are the a.i.'s in Instrata and Interface is a mixture of iprodione and trifloxystrobin, both mixtures have good activity on snow mold fungi. Pre-mixed products are not necessarily the best and golf course superintendents can develop their own mixtures. We have last year's snow mold data posted on the Turfgrass Diagnostic Lab's website, but if you are interested please check back in a couple weeks to see this year's data! For those in the Upper Midwest, we will be conducting Snow Mold Field days on April 14th (Minnesota??), 15th (Stevens Point, WI) and 16th (Marquette, MI). Please contact me (jkerns@wisc.edu) if you would like to attend. We do not charge for the events and we will have the specifics after next week. Stay tuned for photos from our more northern sites next week.