Maximizing Nematode Control: Practical Advice from the Field

Newer nematicides like Indemnify® have dramatically reduced the damaging effects of nematodes across the country in both warm- and cool-season turf. Here’s some practical advice from the last few years of on-course use.

  • Every course/playing surface is different – On most golf courses, only some greens or portions of some greens have high enough populations to cause visible symptoms or decreased performance.
  • The straw that breaks the camel's back – Greens with visible nematode symptoms tend to be the same ones each year, likely due to underlying agronomic or environmental issues that enhance the root-feeding stress by nematodes.
  • Symptoms may not be clearly visible – Turf performance that is slightly lower than expected or “just doesn’t fit” is typical under limited stress, but symptoms often amplify quickly when stress increases.
  • Nematodes are often confirmed after all other problems are ruled out – Since nematodes may not be the primary cause of symptoms, symptoms are commonly first diagnosed as stress diseases or other abiotic problems.
  • Initial soil sampling is important – Soil sampling determines if nematodes are present and if so, their levels and species.
  • Symptom alleviation trumps post-treatment nematode counts – Users report an improvement in turf health after application of a nematicide. However, post-treatment nematode counts are frustratingly complicated by inconsistent populations, variable sampling, overlapping lifecycles, competition between nematode species, and the ability of a healthier root system to support more nematodes. Occasionally post-treatment nematode samples show higher populations than pre-treatment samples even though the turf shows marked improvement after application.
  • Indemnify effectively controls most species of plant parasitic nematodes nematodes including root-infecting species like sting, root knot, and ring, and foliar-infecting species like Anguina.
  • Lance nematodes are tough to control – Lance nematodes are a migratory nematode, spending their life cycle both inside and outside the plant. University researchers agree that no currently labeled nematicide will consistently and effectively control lance nematodes.
  • Effective curative control – Curative control is well-documented with the high rate of Indemnify (0.39 fl. oz./1,000 sq. ft.) providing positive visual effects in as little as 2-7 days after application. Additionally, Indemnify provides effective preventive control when applied prior to symptoms of nematode feeding.
  • If using Indemnify to control nematodes:
    • Improvement may be seen in days or weeks, and speed of improvement is directly related to environmental conditions and growth rate of the warm- or cool-season turf.
    • Most effective control of root-infecting nematodes is usually seen with two applications at the high rate (0.39 oz./1,000 sq. ft.) timed 14-28 days apart.
  • Do your due diligence before implementing a management program – Control decisions are highly specific to each course depending on expectations, budget, degree of damage, species and size of populations, etc. Contact as many sources as possible to help with this decision.
  • For more information – See the linked Indemnify Best Management Practices and Indemnify Product Information Sheet below, and contact your Bayer area sales manager if you need assistance.

Symptoms of nematode damage can vary widely across a playing surface. Pictured are two samples taken just a few feet apart on an infected green. Photo: Bayer Green Solutions Team.

Indemnify Best Management Practices
Indemnify Product Guide
Nematode Solutions – Cool-Season
Nematode Solutions – Warm-Season
Zac Reicher

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

Monday, February 4, 2019