Black Canker Black areas form on leaves and spread to engulf and kill larger woody twigs in the summer. If the weather is wet, pink spore masses form on blackened twig cankers. This disease often occurs on trees with blight, See below. Phyalospora miyabeana Do not plant highly susceptible cultivars in the landscape. Blight or Scab Newly formed leaves and twigs are quickly browned in the spring during wet weather.
Infected leaves fall.
Olive-brown spores form on the surface of infected tissue. Venturia saliciperda Apply a fungicide to protect the foliage of highly valued trees.