So the east coast has had a lot of rain recently, but it is starting to warm up, so it’s a good idea to keep an eye out for Brown Patch, or Rhizoctonia solani. This is a common issue with Wintergrass, Couch, Bentgrass, Fescues, Kentucky Bluegrass, Ryegrass & Buffalo Grass.
What to look for
- Brown discoloured circular patches, from a few centimetres up to a metre in diameter, sometimes with a smoke ring of mycelium around the edges.
- “ Smoke rings” appear as thin brown borders around the diseased patches appearing in the early morning.
- Infected leaves are water-soaked and dark, later dying and turning dark brown.
- After the infected leaves die, new leaves can emerge
- On wide bladed species like Buffalo, leaf lesions develop with tan centres and dark brown edges.
When it is likely to happen?
- High relative humidity and temperatures of over 28°C during the day and over 15.5°C at night.
- More than 10 hours a day of foliar wetness for several consecutive days
- Turfgrass species are most affected when night temperatures are consistently above 20°C with high humidity or moisture.
What is Brown Patch?
Brown Patch in Buffalo Lawn Brown Patch is triggered in a similar manner and time of year as the Leaf Spot disease.
These times will mainly be in the warmer months when humidity can be higher. However, Brown Patch may not always be seen in the heat of summer, but instead, be most common on either side of summer.
Brown Patch is most active and aggressive during it’s peak growing conditions. This is when excess water continues to sit on the lawn for long periods of time under humid conditions. These peak fungus-growing conditions are usually brought on by ourselves when we water lawns at night time.
Brown Patch will be identified by circular dying patches of lawn, which will continue to grow in size from the size of a dinner plate up to a couple of metres in diameter. Multiple circles of Brown Patch are common on Buffalo lawns infected by the disease.
The brown and dying leaf of the Buffalo grass will also pull away from the grass stem very easily. On inspection, the lower part of the dead leaf will appear as a rotting dark brown colour.
How to Fix Brown Patch in Buffalo Grass
Prevention is the key to stopping all lawn diseases in a Buffalo lawn, and many of the same preventative measures which stop Brown Patch from taking hold in a lawn will also be the cure.
Here are the key steps to treating Brown Patch:
- Water only in the morning.
- Try to reduce watering as much as possible until the disease is gone.
- Aerate the soil in the affected areas
- Aerate the entire lawn to stop further outbreaks.
- Stop fertilising until the lawn is recovered.
- Apply a fungicide if necessary.
- Wash mowers of all clippings after mowing an infected lawn. above 20°C with high humidity or moisture.
Herbicide to fix Brown Patch
If you are still noticing Brown Patch even after the above suggestions, a good herbicide to fix it is: Mancozeb Plus from Yates available at any hardware store or nursery
Application rates for lawns:
Brown patch, dollar spot (VIC, NSW, SA & WA only)
Rate: Mix 5g (l level cap) to 1 litre of water OR 50g (l0 level caps) to 10 litres of water. Agitate regularly during spraying to avoid settling. For lawns, apply 10 litres of spray per 10 square metres.
Following the above should easily solve the issue, but if you are still having issues take a photo and send it to our growers.