South Africa Turf Disease Guide - Pythium Root Rot (Root Dysfunction)

Disease and Insect Control

22.11.2021

Causal Agent:

Pythium aphanidermatum, Pythium aristosporum, Pythium graminicola, Pythium vanterpooli, other Pythium species.

South Africa Turf Disease Guide - Pythium Root Rot

Susceptible Turfgrass:

Annual Bluegrass and Creeping Bentgrass most susceptible. Bermudagrass and Seashore Paspalum can also be affected.

Symptoms:

Pythium Root Rot is common on highly maintained turf, such as golf course greens. Although symptoms of Pythium Root Rot are typically non-distinctive, this disease can appear as yellow, irregularly shaped patches. The affected turfgrass is thin, off-colour, and slow growing, while the root system is stunted with reduced volume and vigour. Foliar mycelium does not occur.

Conditions Favouring Disease:

Some Pythium species favour temperatures between 0°C and 10°C while others thrive in temperatures between 21°C and 32°C. Pythium Root Rot occurs in areas with high soil moisture, poor drainage, and low light. It also infects locations with low mowing height and excessive wear.

Integrated Turf Management Tips:

Increase the height of cut
Apply optimum amounts of nitrogen, phosphorous, and potash
Reduce mowing frequency and use lightweight mowers
Avoid over-watering
Apply low amounts of nitrogen in the Spring when roots are forming • Minimise the amount of shade
Improve the drainage of the turf
Reduce soil compaction
Apply penetrant fungicides on a preventive basis

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