Updates from university turf specialists
PROFESSORIAL INSIGHT...
Updates from university turf specialists
Source: Turfnet Monthly www.turfnet.com
Dr. Bruce Clarke, Rutgers University, New Brunswick, NJ:
"From a disease, heat and overall summer stress perspective, this has been the worst summer in this area since the late 1980s. Intense heat stress combined with excessive moisture from localized thunderstorms rendered many curative spray programs ineffective. Preventative programs were the only hope this year for diseases like anthracnose and summer patch.
This season also disproved the theory that annual bluegrass only dies from heat stress, as most areas that were properly treated for anthracnose and root diseases were able to survive the heat. For areas that were not preventatively treated for these diseases, the double whammy of intense heat and disease pressure simply took the annual bluegrass out.
Early season moisture allowed for significant summer patch infection of roots that plagued plants all season. Follow-up fungicides only arrested the infection and typically left less than 50% of the root system intact. Fertilizer and curative fungicides such as thiophanate-methyl should help slightly in recovery.
A light frequent Primo program (0.1 to 0.125 oz per 1000 every 14 days) can provide significant health benefits and reductions in anthracnose and summer patch of annual bluegrass. Turf treated with Embark and followed up with Primo every two weeks has reduced disease occurrence by 50% beyond that attributed to Embark alone. The full effect typically is not seen until the second year of the program, so it is important to stay the course into the second season."