Brown Patch / Yellow Patch

Brown rot is caused by two types of pathogens with different temperature requirements. The optimal temperature for Rhizoctonia solani is 25–30 °C, combined with warm nights. Rhizoctonia cerealis, on the other hand, requires a cooler temperature of 10–20 °C.

The symptoms appear as light brown-reddish, irregular spots ranging from 5 to a maximum of 100 cm in size, sometimes with a gray-blue ring around the edges of the affected areas. Rhizoctonia cerealis causes more yellowish, band-like spots. Both the roots and the stems can be affected. The root collar and growing point usually remain intact. For this reason, damaged areas regrow relatively quickly. Only rarely does the lawn die off completely. However, mixed or secondary infections are common.

Factors that promote infestation:

• High humidity, no wind, and dew

• Cut too deep

• Nitrogen Excess and Burst Growth

• Nutrient deficiency

• All types of grasses can be infested

Preventive measures:

• A balanced and consistent supply of nutrients

• Avoiding rapidly soluble forms of nitrogen

• Fertilization with Slow-Release Nitrogen

• Targeted potassium supplementation during the summer months

• Optimizing irrigation techniques; irrigate in the early morning hours to allow the crop to dry quickly

• Remove dew (e.g., by using anti-dew agents and penetrating wetting agents)

• Increase the cutting height

• Reducing Thatch in the Lawn

• Optimize Air Flow