Michigan State University Extension
Ornamental Plants plus Version 2.0 - 00000009
01/01/98
Needle and twig blight caused by Rehmiellopsis balsamae results in the shriveling and reddening of the new growth. The needles of current seasons growth are curled and dead. Terminal growth and some laterals may be killed.
Pine Twig Blight caused by the fungus Cenangium ferruginosum is a problem on stressed trees. The fungus will not ordinarily be a problem unless the host plant is weakened. The infection usually begins at the terminal bud near a branch tip. Infection takes place in late summer and the disease progresses down a twig into a node. At times the infection may go into 2 year old wood. Needles on infected branches turn reddish then die. Cut off and destroy infected twigs.
Several different fungi cause cankers on the trunks and branches of firs. Cankers are sunken areas in the bark that gradually get larger. When the stem is completely encircled the part beyond the canker dies. There is no chemical control for canker diseases. Keep the plants healthy by fertilizing and watering during dry weather. Cankers can be prevented by avoiding plant injury.
Root rots caused by several fungi kill roots and rot wood. Little can be done to control the diseases other than to keep trees healthy. Maintain tree health by regular fertilization and watering during dry weather.