Driving along Kauffmans Mill Road behind the White House property one spring afternoon, I noticed a bizarre golf-ball sized thing resting in the branches of a cedar tree next to the road. A weird brown sea anemone, tentacled and soft-bodied, had attached itself to the dark green needles, and was swaying lightly in the breeze. What strange biology would have allowed this small ocean dweller to have taken flight and made its way to the Page Valley?
I got out of my truck to better examine its numerous little fleshy arms. Seeing no evasive movement as I got closer, I slowly touched its cool moist body. For the record, I do not recommend the touch-it-to-see-what-happens approach when encountering the unknown in the outdoors. Many a camper has been surprised at the viciousness of doing exactly this with stinging nettles, poison oak, various caterpillars, etc.
Research revealed that it is called cedar-apple rust and is a disease caused by the fungus gymnosporadium juniperi-virginianae. The orange-brown gelatinous sprouts appear in
the spring following periods of rain from a hard gall on a host in the juniper family. These hosts include eastern red cedars which grow extensively in Page County. There are many types of rust but those in this genus also need a host in the rosaceous family to complete their life cycle.
The orange-brown growth spreads spores which then cause lesions on the leaves of apples, pears, crabapple, hawthorn, quince and serviceberry. On the underside of the affected leaf, fruiting bodies called aecia develop from the lesions, spreading more spores, sometimes for miles, to the next juniper host where the cycle is repeated. The rust does not harm the juniper, but on its secondary host – particularly apples – can cause leaf loss, retarded growth, reduced quantity and quality of fruit and sometimes kill the tree.
The effects of cedar apple rust can be significant on commercially grown fruit trees and ornamentals. Disease resistant varieties have been developed and some growers use registered fungicides to control the problem. We will keep you posted if we see any of the lesions appear on the apple trees which were just installed in the heirloom fruit orchard at the farm.
Otherwise, in the wild, these odd formations just serve to remind us of the interesting interactions between plant species and the diseases which affect them.
– Chris Anderson, WHFF Executive Director