I have Pythian blight and in another area of the lawn a rust that has formed on the turf. How can I get rid of I it before it destroys the lawn?
Both lawn diseases, Pythium blight and Rust, have most likely developed due to the hot and humid weather conditions that southern Ontario has been experiencing this summer. Although treatment for each includes minimizing and controlling the amount of moisture the turf receives, improving air circulation to dry the turf is also an effective control. If there are trees and shrubs that shade your lawn, pruning them would help to promote air circulation and allow for better light penetration. Good soil drainage will also minimize the persistence of these lawn diseases, especially during periods of hot, humid weather.
Interestingly, increased levels of nitrogen are often a cause of Pythium blight, whereas Rust is often caused by low nitrogen fertility in the soil. If your lawn is being fertilized on an annual basis (usually in the spring and/or the fall), perhaps some areas of your lawn will require different levels of fertilizer to maintain good health.
For more information about Pythium blight, please see: www.guelphlabservices.com/files/PDC/041TurfPythium.pdf and https://www.extension.purdue.edu/extmedia/bp/bp-109-w.pdf
For more information about Rust, please see: https://extension.illinois.edu/lawntalk/weeds/rust_diseases_in_home_lawns.cfm and https://www.extension.purdue.edu/extmedia/bp/bp-110-w.pdf
Recommendations for managing and preventing the spread of these diseases include:
- Water infrequently but thoroughly, when necessary, early in the morning.
- Increase the mowing height and mow more frequently–may reduce severity of problem.
- Reduce shade and improve air circulation.
- Plant resistant varieties of turf grass
If the problem cannot be managed by using the above cultural controls, perhaps you should contact a reputable lawn service. However, if you can prevent these diseases from spreading in the short term, cooler and less humid weather should help to minimize any further damage to your lawn.