Rhizoctonia spp.

Description:

Often starting as small brown discoloured circles or patches as small as a few centimetres in size. The patch can grow in diameter up to a metre and a distinct grey-brown colour "smoke ring" can be observed around the perimeter of the affected area in the early morning. Infected leaves look water soaked and dark in colour, later dying. The disease can be found on the foliage and or turf root system.

Susceptible turfgrass:

Most warm- and cool-season turfgrass varieties. Symptoms can vary between turfgrasses as seen within the pictures above.

Favourable conditions:

High humidity and warm surface temperatures (>25 degC), excessive soil moisture, poor drainage, excessive thatch and high nitrogen.

Control options:

• Pesticides: See available tabs below for registered products. Although several fungicides are labelled for control of brown patch, effectiveness is much greater when applied before the disease becomes well established. Use as per label instructions.
• Integrated Pest Management (IPM): Use a combination of approaches listed on this page.
• Cultural:
  • To reduce the severity of brown patch, irrigate only when needed and do so early in the morning to reduce having wet foliage particularly overnight.
  • Brown patch severity is directly related to the fertility status of the turfgrass. High nitrogen tends to increase disease severity. Provide a balanced fertiliser program.
  • Reduce thatch levels and improve soil drainage.
• Mechanical: Nil.

Disclaimer:

Turf Finder or its developer accepts with no responsibility for any consequences whatsoever resulting from the use of any information or product(s) listed herein. Products are to be applied as per label instructions.