Professionals only: Rust/dollar spot thriving in lawns – Turfgrass Science at Purdue University

Professionals only: Rust/dollar spot thriving in lawns

The diseases rust and dollar spot are thriving in Indiana lawns right now, which is fairly typical for this time of the year. These are both low nitrogen diseases, so are almost inevitable as we try to keep lawns on the lean side during the summer to minimize devastating damage from pythium, brown patch, heat and/or drought stress, which are all more damaging under lush high nitrogen conditions. Plus with the cool summer and fairly frequent rains encouraging above average growth and nitrogen use, and the economy forcing lower nitrogen rates, and it is no surprise that these diseases a running amuck. Following are more turf tips with details on life cycle and management. In a nutshell, immediate satisfaction on a home lawn can be achieved by a single application of a fungicide. This will provide maybe 14 to 28 days of control and even though we almost never recommend fungicides on a home lawn, it may be justified with the most adamant of homeowners. Your fall fertilization is still a couple of weeks away, but these applications could probably moved up on your most troubled lawns as long as temperatures stay in the lower to mid 80’s and irrigation is used. However, the long range forecast is for high 80’s and 90’s and thus this strategy might get risky. To maximize safety of fertilizer applications, reduce the overall rate of N and maximize the amount of slow release N right now. Applying 0.75 lbs N now with slow release N source should help reduce the diseases with little risk of negative effects. In the longer term, increase the annual amount of nitrogen to your lawns most troubled by rust or dollar spot. Adding another application of nitrogen in the late spring or summer and/or increasing each scheduled application of nitrogen by another 10-15% should help reduce these late summer diseases.

 Categories:

Share This Article
Disclaimer: Reference to products is not intended to be an endorsement to the exclusion of others which may have similar uses. Any person using products listed in these articles assumes full responsibility for their use in accordance with current directions of the manufacturer.
Turfgrass Science at Purdue University - Horticulture & Landscape Architecture, 625 Agriculture Mall, West Lafayette, IN 47907

© 2024 Purdue University | An equal access/equal opportunity university | Copyright Complaints | Maintained by Turfgrass Science at Purdue University

If you have trouble accessing this page because of a disability, please contact Turfgrass Science at Purdue University at ashbreed@purdue.edu | Accessibility Resources