South Africa Turf Disease Guide - Take-all Root Rot (Bermudagrass Decline)

Causal Agent:

Gaeumannomyces graminis var. graminis

Susceptible Turfgrass:

Bermudagrass and Ultra-Dwarf Bermudagrass

Symptoms:

Symptoms appear in patches or rings up to several feet in diameter. Patches may coalesce
to form large irregularly shaped areas, especially where turf is stressed from traffic, poor drainage, or shade. Affected turf initially shows symptoms of reduced growth, chlorosis, or leaf dieback. As the turf continues to decline it may turn tan, yellow or orange before collapsing and dying. Roots, stolons, and/or rhizomes are sparse and noticeably rotten in affected areas.

Conditions favouring disease:

The Take-all Root Rot pathogen grows across a wide range of soil temperatures, but most infection likely occurs when the turf is weak or stressed. Low light levels combined with cool temperatures or extended periods of wet weather are the most common triggers. The disease is most severe in poorly drained areas and where soil pH is greater than 7.0. Stress from low mowing, inadequate fertility, excessive traffic, or shade cause the turf to be more susceptible. High populations of plant-parasitic nematodes also contribute to Take-all Root Rot development.

Integrated Turf Management Tips:

1. Maintain soil pH below 7; most turfgrasses perform best when soil pH is between 6 and 6.5.
2. Avoid lime applications unless directed by soil test results.
3. Reduce turf stress by increasing mowing height, providing adequate fertility, and minimizing mechanical wear.
4. Implement a nematicide programme if populations are at damaging levels
5. Cultivate regularly to increase soil aeration and root growth.
6. Improve soil drainage and avoid over- irrigation.
7. Make preventive fungicide applications on a 14- to 28-day interval when conditions are conducive to development.

Just tap the links below to read about other turf diseases. Or download the full free guide at the bottom.

1. Anthracnose
2. Brown Patch 
3. Brown Ring Patch (Waitea Patch) 
4. Dollar Spot 
5. Fairy Ring 
6. Superficial Fairy Ring 
7. Grey Leaf Spot 
8. Large Patch 
9. Microdochium Patch 
10. Powdery Mildew 
11. Pythium Blight 
12. Pythium Root Rot (Root Dysfunction) 
13. Red Thread 
14. Rhizoctonia Zeae (Rhizoctonia leaf and sheath spot) 
15. Rusts: Crown, Leaf and Stem 
16. Spring Dead Spot 
17. Summer Patch 
18. Take-all Patch  and
19. Take-all Root Rot 

If you would like to have a complete copy with all the turf diseases, you can download it on the link below.