South Africa Turf Disease Guide - Summer Patch

Disease and Insect Control

22.11.2021

South Africa Turf Disease Guide - Summer Patch

Causal Agent:

Magnaporthe poae

Susceptible Turfgrass:

Fine-Leaf Fescue, Kentucky Bluegrass and Poa Annua

Symptoms:

Summer Patch appears as circular or irregularly shaped patches that measure from several inches to several feet in width. Initially, patches appear as slow-growing thinned or wilted turfgrass. Mature patches are brownish-yellow to straw-coloured and can coalesce as they increase in size. The leaves of the plant turn yellow to brown from the tip to the base. The roots turn moderate to dark brown. Summer Patch can exhibit a ring-like appearance where a less susceptible grass species survives inside the diseased patch.

Conditions Favouring Disease:

Root infection is initiated when soil temperatures exceed 18°C; however, foliar symptoms of Summer Patch are favoured by temperatures over 29°C during the day and over 21°C at night. It is also commonly found in areas that are sunny, exposed, and with high soil moisture, high soil pH, compaction, poor drainage, and low mowing height. This disease is typically more severe in turfgrass that has been fertilized with nitrate-nitrogen.

Integrated Turf Management Tips:

Use acidifying fertilizers
Increase the height of cut
Reduce soil compaction through aerification and use of lightweight equipment
Syringe when the temperature is over 29°C
Improve the drainage of the turf
Convert to resistant species, such as tall Fescue, Bentgrass, or Perennial Ryegrass
Apply fungicide preventively in Spring

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