Root Pathogens in Bermudagrass Greens in the Shoulder Seasons

Maintaining healthy ultradwarf bermudagrass greens can be difficult in summer due to a combination of several biotic and abiotic stresses.

• Mechanical stress
  • Low heights of cut contribute to shallow roots on golf course putting greens
  • Cultivation from aggressive core aeration and verticutting create additional root stress, as the turf converts energy from stored carbohydrates in roots for recovery
  • Even though bermudagrass thrives in summer, photosynthesis of warm-season grass starts declining in temperatures above 90oF. High temperatures combined with reduced sunlight (continual cloudy weather) can dramatically reduce photosynthesis while increasing respiration
  • Hot and cloudy summers followed closely by cooling weather in the shoulder season can compromise bermudagrass throughout the winter
• Root pests/pathogens
  • Weakened roots are more susceptible to nematode damage, which creates more potential openings for root pathogens such as Pythium
  • Research from the University of Florida shows sting nematodes amplify Pythium infection versus roots inoculated with Pythium by itself
• Cultural solutions
  • Raise mowing height incrementally or alternate mowing and rolling
  • Sand topdress regularly to help raise “effective” height of cut
  • Vent with solid tines to improve drainage and increase soil oxygen
  • Reschedule cultivation programs if cloudy, wet weather persists, especially during mid-summer heat
  • Consider less aggressive cultivation alternatives
• Envu solutions
  • Tank-mix Signature™ XTRA Stressgard^® (2 oz/1000 ft2) + Banol^® (2 oz/1000 ft2) +  Indemnify^® (0.2 oz/1000 ft2)
  • Signature XTRA Stressgard – Cornerstone of a greens program, backed by years of research, proven Pythium control and Stressgard’s ability to:
    • Increase photosynthesis
    • Increase root growth
    • Increase chlorophyll
    • Increase cellular membrane stability of stressed turf
  • Banol - Provides highly effective Pythium root rot control, especially when combined with Signature XTRA, and no documented history of resistance
  • Indemnify – Highly effective nematicide providing excellent sting and root-knot control
  • Watch for Envu’s new Resilia™ this fall that will eliminate the need to tank-mix to control root pathogens
  • If mini ring is an issue, Envu’s Deniscor^® is highly effective on mini ring as well as fairy ring and take all root rot, while affording excellent turf tolerance
  • Though applications for take all root rot should have been started in mid-summer, DMI fungicides like Mirage^® Stressgard, Tartan^® Stressgard, or Deniscor should be continued in to the fall for take all
• Need more info? – Always follow label instructions and contact your Envu area sales manager if you need assistance

Stress factors such as nematodes, pathogens, mechanical stress plus poor weather can weaken roots when left unprotected with nematicides and fungicides (right) (Envu).