Daylily Rust

Allen Park, MI(Zone 6a)

Daylily rust has arrived

Jan Byrne, Diagnostic Services
Daylily rust is a new disease on daylilies, and in the last week it was found at two locations in Michigan. The disease was first found in Georgia in August 2000 and, shortly thereafter, was confirmed in Florida, Alabama and South Carolina. The disease has continued to spread and, this year it has been confirmed in at least 24 states including the nearby states of Illinois, Pennsylvania, Ohio and Indiana.

The disease caused by the fungal pathogen Puccinia hemerocallidis, is a major concern to propagators, nurseries and home gardeners. The disease causes lesions on the foliage and completely kills foliage on especially susceptible cultivars. Researchers do not know whether or not tubers can be infected. Once the disease is established, intensive scouting, removal of infected foliage and regular fungicide applications are all needed to control the disease. The Michigan Department of Agriculture is likely to invoke quarantines restricting the sale of infected plant material at nurseries.

There is not a lot of information known about the biology of this pathogen. The fungus has a short incubation time, spores are produced within 7 to 14 days after the foliage is infected, and the spores are then spread by wind. The pathogen has other hosts (Patrinia spp. and possibly Hosta spp.) but does not need them to complete its lifecycle. The ability of the pathogen to overwinter or survive on infected plants throughout a Michigan winter is not known. More information about the disease and images of the symptoms are available at two web sites:
www.ces.uga.edu/agriculture/plantpath/daylilyrust.html and
www.aphis.usda.gov/npb/daylily.html

Chemical control of the disease is still under investigation. Trials conducted by Dr. Williams-Woodward at the University of Georgia found that Daconil Ultrex (chlorothalonil), Fore (mancozeb) and Heritage (azoxystrobin) applied with a surfactant are effective when applied prior to inoculation. The number of times Heritage can be applied is limited, so this product should be rotated with other effective products – consult the label for more details. Plants suspected of having daylily rust can be submitted to Diagnostic Services (517-355-4536). This disease can be confirmed relatively easily and results are usually faxed back on the same day that samples are received.

Toadsuck, TX(Zone 7a)

I'm bring this back up due to our Day Lily CoOp...just to remind ourselves.

"eyes"

Post a Reply to this Thread

Please or sign up to post.
BACK TO TOP