Start Early to Control Pythium Root Rot In Cool-Season Greens

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Pythium root rot (PRR) can be a major problem on cool-season putting greens. Though most are working with limited staffs with COVID-19, PRR is one disease that preventative controls employed soon can save potential serious damage if and when the summer brings hot and wet weather.
  • Symptoms
    • Chlorotic, yellow to orange patches or streaks in drainage areas, or thinned areas especially during periods of extended rainfall and high heat
    • Can also be a problem in water-logged soils in the spring or during cool, slow-growth periods.
  • Cultural control – any practice to keep the profile as dry as possible will reduce PRR.
    • Improve internal drainage.
    • Regular aerification and topdressing.
    • Reduce irrigation with hand watering and using moisture meters.
    • Reduce stress by using rollers to reduce mowing frequency and potentially raise the mowing height.
    • Recent research from University of Florida strongly suggests that nematodes enhance infection and damage from Pythium root rot.
  • Preventive fungicide programs
    • Start when 2" soil temperatures average 60°F for five consecutive days.
    • Water in the products after application to depth of root system.
    • Start with applications on 3-4 week intervals until summer heat starts, then move to 14-dayintervals.
    • Rotating modes of action is critical to limit the chance of resistance as well maximizing control over the wide range of the over 30 Pythium root-infecting species reported to cause PRR.
  • Fungicide Solutions
    • Many start with spring applications of Banol® at 2-3 oz./1,000 sq. ft. (Banol First Program).
    • Ensuing rotational applications include Signature® XTRA Stressgard® alone or in combination with Banol for Pythium control and to maximize plant health.
    • Segway® (Ishihari Sangyo Kaisha, LTD) is an effective rotational fungicide.
    • Many fungicides with the QoI mode of action (FRAC code 11) are also effective in the rotation.
  • For more information – See the attached Green Solutions Sheet below for more information, and contact your Bayer area sales manager if you need assistance.

Pythium oopsores infecting roots can result in long-term turf decline (Bayer)

  Bayer Solutions - Pythium Root Rot
Zac Reicher

by Zac Reicher , Ph.D., Green Solutions Team Specialist

Sunday, March 29, 2020

Rob Golembiewski

by Rob Golembiewski , Ph.D., Green Solutions Team Specialist

Sunday, March 29, 2020