Anthracnose lawn disease

Anthracnose is caused by the fungus Colletotrichum graminicola. It can attack most species of grass on the lawn butannual meadow grass (Poa annua) is very susceptible (hence the previous name of this disease was 'Basal rot of Poa annua'). Antracnose is a stress disease attacking grasses that are under stress due to environmental factors.

Identification of anthracnose

Anthracnose usually appears on the lawn during the late summer and can persist well into winter, even into the following spring. Be vigilant and look for annual meadow grass plants that are starting to turn yellow, with the youngest leaf turning an orange to red colour on infected plants. As the severity of this disease increases the patches can grow to 150mm in diameter and the base of the infected area turns black.

Causes of anthracnose

As we previously mentioned anthracnose is a stress disease so pay attention to keeping the lawn in a healthy condition with good lawn care practices.

• Ensure the lawn receives adequate nutrition, (however it is important not to over apply nitrogen during the late summer and autumn as it may lead to problems with fusarium patch disease).
  
• Soil compaction can also influence anthracnose.
  
• Prolonged leaf wetness will encourage anthracnose to spread.
  
• Hot and dry conditions leading to drought stress, will encourage anthracnose.
  

How to prevent and cure anthracnose

To put it simply pay attention to remedying the causes of anthracnose

• Ensure the lawn receives adequate nutrition to keep the grass in healthy condition.
  
• Relive compaction with aeration, in the form of slitting, spiking or even hollowtining.
  
• As anthracnose predominantly attacks annual meadow grass reduce the amount of this grass in the lawn by encouraging disease resistant grasses with good lawn care management practices.
  
• Raising the height of cut on the mower will also help reduce the stress levels of the grass and help combat the spread of anthracnose.
  
• Reduce the time that the leaf surface remains wet by removing early morning dews.