Reaction of Bentgrass Cultivars to a Resistance Activator and Elevated CO2 Levels When Challenged with Microdochium nivale, the Cause of Microdochium Patch

Abstract

Climate change prediction models forecast increased CO2 levels and temperature changes. Microdochium nivale is a common pathogen of turfgrasses in temperate climates, and these changes may increase Microdochium patch disease severity. This research involved experiments on cultivars of Agrostis spp. and Poa annua inoculated with M. nivale and incubated under two CO2 concentrations. The efficacy of a resistance activator, Civitas + Harmonizer, was tested on eight cultivars that were grown under 400 or 800 ppm of CO2 during a 15°C/10°C (day/night), 16‐h photoperiod. The grasses were treated with water or Civitas + Harmonizer and inoculated 1 wk later with M. nivale. Disease severity was lower at 800 ppm than at 400 ppm of CO2, and the application of Civitas + Harmonizer decreased disease symptoms. This research will be useful for recommendations on turfgrass cultivars for northern temperate zone golf courses and on sustainable management practices to face the challenges of climate change.