DISEASE

NAME
Dollar Spot
Various Dollar Spot Species

Description
This is a fungal problem in fine turf grasses causing dead patches. There are several species of fungus involved including Sclerotinia homeocarpa.

Symptoms
Mottled dead patches or spots appear in lawns up to 90mm across and under severe cases they coalesce forming large irregular dead patches. As the leaves rot they become slimy and the surface may have a fluffy appearance when fruiting bodies appear. On closely mowed lawns smaller areas mycelium may be observed as white webbing early in the mornings when the dew is still present.

     Agrostis palustris


The fungus overwinters in the crowns and roots of the turf becoming active when temperatures range from 16 şc to its peak at 27 şc particularly in humid conditions.

Source and Dispersal
The fungus is commonly found in most soils and is dispersed by wind or water. The mycelium produces sclerotia that develop funnel-shaped ascocarps.

Favoured Conditions
It is more prevalent in areas that have heavy dews from late spring and is more widespread in early autumn during wet weather, preferring compacted soils that have low nitrogen content.

Affected Plants
Fine turf grasses that are susceptible including, Festuca, Zoysia, Stenotaphrumand Eremochioaspecies.

Agrostis palustris     

Agrostis palustris(Bent) is particularly infected by this fungal disease.

Non-chemical Control
Apply a nitrogen fertiliser to the affected areas and aerate by spiking the soil or improve the drainage.

Chemical Control
Areas may be sprayed with a fungicide such as traidimefon or carbendazium.
Note
Always read the label for registration details and direction of use prior to application of any chemicals.