Winter drying is the most common cause of injury to pines. Evergreens keep their needles and continue to transpire water. If the soil is dry or frozen, the plant cannot replace water lost and the result is scorching of the needles. Again, results are confusing, and can be confused with diseases. Call a professional if in doubt.
Crabapples are very susceptible to apple scab.
The scab fungus affects leaves, flowers and fruit. The fungus begins with dark olive green spots on leaves which turn brown and spread causing chlorosis and eventually turning totally brown. The fruit appears rough and scaly. The leaves prematurely drop and will result in loss of tree vigor. After several years of infestation death may occur, or seriously deform the tree.