Posted by Jim at 8:53 AM Wednesday, August 12, 2009 Labels: brown patch , dollar spot , fungicides , fusarium patch , gray snow mold , Microdochium patch , Midwest , pink snow mold , Typula ishikariensis
Although the temperatures are on the rise in the Midwest, a couple of superintendents have asked me about snow mold fungicides. So I thought this would be a good time to give a brief synopsis of our snow mold research from 2008 through 2009. Here is the link for our full snow mold reports, where you can view all of the treatments we tested: http://www.plantpath.wisc.edu/tdl/pdf/uwsnowmoldreports2009.pdf. First you need to know where you stand in relation to the map on the upper right hand corner of this post. If you are above the line than you need to consult the report for Wawonowin CC in Champion, MI. If you are below the line than you should consult the report from Sentryworld Golf Course in Stevens Point, WI.
Conditions at Sentryworld Golf Course in Stevens Point, WI were approximately 100 days of continual snow cover. Early applications were applied on October 21, 2008 and late applications were applied on Nov. 25, 2008. Many treatments were highly effective at this site, so please consult the report to see each treatment in detail. Some of the best performing treatments that were only applied late were Trinity (1 fl oz), Trinity (1 fl oz)/Iprodione Pro (4 fl oz), Triton Flo (0.85 fl oz)/Compass (0.25 oz)/Daconil Ultrex (5 oz), Instrata (9.3 fl oz), Quali-Pro TM/C (6oz)/QP Iprodione (4 fl oz)/QP Propiconazole (2 fl oz), 26/36 (4 fl oz)/Endorse (4 oz) and Chipco 26GT (4 fl oz)/Daconil WeatherStik (5 fl oz). Slashes represent tank mixtures and all rates are per 1000 sq ft. By no means is this list all inclusive, so please do check out the full report.
The dominant disease was gray snow mold, but Microdochium patch was observed at this site. If Microdochium patch (pink snow mold, Fusarium patch) is the dominant winter disease you face, typically an application of propiconazole or iprodione tank mixed with chlorothalonil will provide acceptable control.
The conditions at Wawonowin CC were much more severe than the conditions in Stevens Point, WI. There was continuous snow cover on the plots for approximately 170 days. The pressure was so extreme that most of the treatments that were effective in Stevens Point failed. The dominant snow mold pathogen was Typula ishikariensis, yet Microdochium patch was observed at this location. Early treatments were applied on October 2, 2008 and late treatments were applied on October 28, 2008. The only treatments that provided complete control of snow mold at this site were, an experimental from Bayer tank mixed with Triton Flo (treatment 29), 26/36 tank mixed with an experimental from Cleary's (treatment 61) and 26/36/Endorse/CX-28. However a few treatments did provide acceptable control (< 5% disease severity), please consult the reports for more specific information on these treatments.
Again this list is not all inclusive as there were some other treatments that did provide acceptable control. Application timing for snow mold fungicides is critical. It is not necessary to wait until the snow is falling to apply fungicides targeting snow mold. An old adage from one of my predecessors, Dr. Gail Worf, is spot on! Before deer season (rifle) starts in Wisconsin, which is the weekend before Thanksgiving approximately, snow mold applications should be down! Especially for those in areas that receive more than 100 days of continual snow cover. Basically you can use the reports to find a fungicide or fungicides that fit for your courses budget and situation.
Presentely the weather has warmed up in the Mid-West and dollar spot has started to surge. Brown patch is kicking back into gear and anthracnose has finally developed in a few places. It appears that the weekend is going to be warm, but not very humid so brown patch may not linger for very long. The Turfgrass Diagnostic Lab has been fairly slow the last month or so because of the extremely cool July we experienced.