Kikuyu Patch on Our Fairways

Kikuyu Patch

Kikuyu Patch, the most common fungus attacking Kikuyu grass areas on Golf Courses here on the Highveld, is caused by a simple organism, similar to a fungus that feeds on rotting material or living plants by absorbing nutrients through fine threads in the Kikuyu specie.

 Above: A picture with a harsh infection of the Kikuyu Patch disease. This fungus is called Verrucalvus flavofaciens and is the primary disease of turf and pasture types of kikuyu.

Facts, Identification and Progress of Kikuyu Patch Disease:

·         As from autumn, when a decline in soil temperatures can be expected, this fungus infects the root system and causes severe root rot leading to plant death.

·         The fungus thrives in the presence of high soil moisture.

·         Disease symptoms are consistent and are expressed as a yellowing which becomes circular as the affected area expands from a R5 coin size to the size of a Green!

·         The centre of the circle dies and as kikuyu does not re-grow in the centre, the patch can become suitable for other grasses and broadleaf weed species to flourish.

·         The disease is usually most noticeable just before spring.

The Current Management Procedures used on PCC:  

·         Annually switch-off all irrigation on Kikuyu areas (E.g. Fairways, Tee’s and Green Surrounds) as from autumn (1 May), the excessive moisture encourages the fungus to produce more rapidly.

·         Prevent spread by not mowing infected soils during autumn and throughout winter, thus not transferring the fungus around on machinery.

·         Prevent spread by not moving infected soils and grass to new areas.

·         During our Spring Treatment Programme we scarify, sweep and top-dress these areas with a nutrient rich lawn-dressing and then fertilize with a quick boost Nitrogen fertilizer.

Fungicidal control

While there are currently NO registered chemical controls for the disease yet, it can be masked to a degree by Nitrogen fertilizer applications as soon as the soil temperatures reach an appropriate level.

Even though, we are also experimenting with a few different products to try and suppress the further development and spreading of this disease with great success during the past 4 years.

Above: This picture clearly shows the centre of a Kikuyu Patch circle, where the Kikuyu has died and not re-grown. This infected patch has now become suitable for other grasses and broadleaf weed species to produce.

References

·         Soil-Borne Turfgrass Diseases – by Kaylene Bransgrove

Department of Primary Industries and Fisheries, Redlands Research Station, Cleveland.

·         Kikuyu (Pennisetum clandestinum)- by Geoff Moore,

Department of Agriculture and Food in Western Australia.

·          Syngenta – Greencast