The pathology papers are among the most popular at these meetings each year and this year was no exception. As I penned on Day One the the potassium effects on anthracnose was a highlight and it continued with an excellent presentation by Professor Ingugiato from UConn on Summer patch.
Professor Ingugiato investigated the role of compaction, cultivation and Mn applications on Summer patch incidence and severity. It makes sense that a root infecting fungi such as Summer patch would be worse when rooting is further restricted by compaction and theoretically could be alleviated by hollow or solid tine cultivation.
The Mn angle was intriguing as it required one to know that the Summer patch organism that infects annual bluegrass is similar to the Take-all patch organism that infects creeping bentgrass roots. It has been well established in wheat and bentgrass that Take-all patch restricts Mn uptake. However this is not well established for Summer patch.
Interestingly, both cultivations provided some relief from Summer patch yet hollow tine was slightly more effective. Still neither cultivation programs provided the relief afforded by Mn applications. Therefore, a nice simple conclusion, if you have a history of Summer patch, of course work to alleviate compaction, but be sure your Mn applications are consistent.