Dollar Spot: Causes & Treatments
What causes Dollar Spot?
Dollar Spot is a turf disease effecting many different turf varieties. As its name suggests, the appearance of this disease is usually identifiable as dollar sized spots of discoloured grass appearing within your lawn. Up close, the discoloured leaves will have straw coloured lesions with red/brown edges to them. If left to spread the spots will get larger and form bigger patches of affected grass.
Another identifying feature of Dollar Spot is the web like fine threads that form through the leaves of your lawn on colder mornings. These webs will disappear as the day warms up, but these threads are called mycelium threads and are a product of the fungal pathogen known as Sclerotinia Homoeocarpa.
When does Dollar Spot occur?
Dollar Spot occurs when additional moisture is present on warmer days and spring and autumn cool nights. Excessive amounts of thatch build up, poor drainage and watering your lawn too often are common factors that can result in the spots appearing. Dollar Spot is much more common in turf under intensely managed conditions, so is commonly experienced on golf courses.
Humidity
Low nitrogen levels
Cool nights with heavy dew
Dry soil
Treatment
So often with fungal diseases, the best remedy can simply be good lawn care practices
Regularly fertilising your lawn throughout the year will prevent nitrogen deficiency
Regular mowing will help to reduce thatch build up, which can create an ideal humid environment for the disease to grow
When watering your lawn, be sure to do so in the mornings and afternoons only and only water your lawn when it really needs it. A long deep soaking will be of much better benefit than many short watering's
Alongside the above, you can also add the following fungicides to your lawn:
Chlortan 720 is a contact fungicide for the treatment and prevention of common turf diseases in Perth lawns. It is effective against the fungal diseases most likely to affect residential and commercial turf in Perth's mild, wet winters — including brown patch, dollar spot and helminthosporium leaf spot.
As a contact fungicide, Chlortan 720 works by direct contact with fungal spores and mycelium on the leaf surface. Apply at the first sign of disease — brown or yellow patches that do not respond to watering and do not follow the pattern of dry patch are typically the early indicators. Early treatment produces significantly better outcomes than late-stage intervention.
For persistent or recurring fungal issues, rotate Chlortan 720 with a systemic fungicide such as Heritage Maxx to prevent the development of fungicide resistance and to treat disease that has moved below the leaf surface into the root zone.
Reduce watering frequency when applying fungicides — moist leaf surfaces through the night are the primary driver of fungal disease spread in Perth winters. Water in the morning to allow the lawn to dry before evening.
Compatible with all turf varieties. Follow label directions for dilution rates and repeat application intervals.
Mancozeb Plus is a professional grade fungicide combining the benefits of both Mancozeb and Wettable Sulphur.