Sapstreak Disease (Ceratocystis coerulescens (C. virescens))

Sapstreak disease can be a serious problem in the sugarbush. The causal organism is one of the most common stain fungi of northern hardwood logs and bolts. It can enter and kill wounded trees. The primary avenues of infection are root and buttress injuries made by skidding or sap hauling (Fig. 103). Recent observations also suggest that trees can become infected through stumps created when sprout clumps are thinned (Fig. 104). Outbreaks of sapstreak always have been associated with logging or with sugaring. There is no evidence that broken branches, insect injuries, or even tapholes are suitable sites for infection to being.

A sparse crown usually is the first sign that a sugar maple tree has sapstreak. Leaves often are one-half or less than normal in size (Fig. 105). Sometimes, trees die suddenly. In fact, trees without symptoms during one year may fail to leaf out the next; others may succumb within a year or so. By contrast, some trees may linger for many years, showing progressive dieback before they die. Some may even recover.

Cornell Cooperative Extension Cornell University Extension Forestry