Phytophthora crown rot

Phytophthora crown rot is a disease of tree fruit, most notably apples.  Symptoms include reduced tree growth, which can include yellowing of the leaves.  Trees may die slowly over a year or two or rapidly.  Rapid death usually occurs following excessively wet periods. To see symptoms appearing below the ground at the crown, a few inches of soil needs to be removed.  Underneath the outer bark layer, a red-brown color will be observed on the inner bark.