Snow Mold Disease Control on Creeping Bentgrass October 2003 - May 2004

Eight chemical and control treatments were evaluated on a 10.5-year-old sward of creeping bentgrass in southern Ontario during October 2003 to May 2004 for grey and pink snow mold control. Separate sets of plots were inoculated with Typhula incarnata or Typhula ishikariensis for grey snow mold, or Microdochium nivale for pink snow mold. The fungicides tested included Quintozene (250 g /100 m2), which is registered and recommended for controlling snow mold diseases of turfgrass in Ontario, plus five other treatments involving chemicals provided by Cleary Chemical Corporation for snow mold control. Spectro 90 WDG pretreatment was applied on 15 October 2003 to three of the treatments, and all other treatments were applied 15 November 2003 over bare ground. Inoculum was applied on 28 November 2003. Biotic plus abiotic injury was assessed as winter injury weekly from 25 March (snowmelt) until 7 May (greenup). After snowmelt and at greenup, all treatments provided excellent results with significant suppression of both snow molds, and with overall winter injury less than 10% area affected. Winter injury results for 25 March and 7 May 2004 are presented.