Cold-induced cankers and associated fungi in a sycamore seed orchard

Abstract

Of the trees in a 6-year-old sycamore seed orchard in Carlisle County, KY, 66 percent developed obscure vertical cankers in the spring of 1990. A variety of wound-invading saprophytes, including Hyalodendron sp., Stachylidium sp., Botrytis sp., Phialophora sp., Trichoderma sp., and Fusarium sp., were isolated from canker wood. Weather records indicated that trees were subjected to abnormally low temperatures from December 15-25, 1989. Five clones demonstrated an apparent tolerance to the cold damage, but there was no correlation between clone response and geographic origin of the clones. The consistent southern orientation of cankers, record low temperatures in 1989, and apparent absence of virulent pathogens strongly suggest that the cankers resulted from freeze damage.