Take-all patch

Understanding Take-All Patch

Take-All patch, caused by the fungus Gaeumannomyces graminis, is a destructive turf disease primarily affecting cool-season grasses like bentgrass (Agrostis). The disease commonly emerges in mid-spring and early autumn, affecting turfgrass health and appearance, particularly on golf courses, sports fields, and lawns.

Conditions Favouring the Disease

Certain environmental and management practices contribute to the development and spread of Take-All patch. Sterile soil conditions, such as those in newly constructed sand greens, often lack the natural microbial diversity that combats harmful fungi. Poor aeration reduces oxygen availability to grass roots, making them more susceptible to disease. High alkalinity, due to over-liming or irrigation with alkaline water, creates an environment in which Gaeumannomyces graminis thrives.

Identifying Take-All patch Symptoms

Distinctive symptoms make the disease relatively easy to identify. Affected turf shows patches of bronzed or bleached bentgrass up to 30cm in diameter. The centres are often colonised by fescues, Poa annua, or broad-leaved weeds. These patches might also be slightly sunken, further accentuating their visibility. Unfortunately, recovery is slow and laborious, necessitating proactive disease prevention and control.

Preventative Measures

Preventing Take-All patch involves creating an unfavourable environment for the fungus and maintaining vigorous turf health.

• Soil pH Management: Avoid applying lime unless absolutely necessary, and test the water supply for high lime content.
• Nutrient Management: Use fertilisers containing iron or ammonium sulphate to acidify the soil surface and maintain a balanced supply of essential nutrients.
• Cultural Practices: Regularly spike or aerate the soil to improve drainage and increase oxygen levels.
• Disease Monitoring: Be vigilant about early signs of disease, especially under conditions conducive to its development.

Control Strategies

Control is possible with approved fungicides. However, fungicide use should be combined with preventative cultural practices to maintain healthy turf and minimise the likelihood of future outbreaks.