This fungus gets into plum and apple trees through wounds in bark caused by insects, natural stressors, and/or improper pruning. The trees have the growth slows and dry prematurely. Apple trees (Malus spp.) The two most common symptoms of wood rot are the breakage of limbs or main trunk and the presence of fruiting bodies on the bark or wood surface (figs. Peel back the bark from the trunk. It gets inside the tree through the blossoms and through the bark. This disease is found mostly in southern states, since it needs warm weather to thrive. Photo by William M. Brown Jr., Bugwood.org via CC 3.0. Bitter Rot. Apple tree root rot produced by the funguses from the Phytophthora Genus. Remove the soil from around the trunk and look at the crown. It causes your tree to decay, dry out, and crumble into pieces. However, fungi do not always produce fruiting bodies, and fruiting bodies occur less commonly on certain fruit tree … In the basal area of the trunk appears similar lesions with those produced by the crown gall. Brown Rot – This is the most serious version. The fungus gets into the apple tree originally via open wounds in the tree from broken branches and cracks in the trunk. 1, 2). Black rot can stress an apple tree if it strikes the tree year after year, robbing it of leaves and nutrients. Another ominous disease that affects fruit trees in Ontario, black rot is caused when the bark of hardwood fruit trees is infected by the fungus Botryosphaeria obtusa. This can manifest in the following three ways. It occurs where the apples have had physical damage. Your tree may have an obvious decline that could be due to many factors, including fire blight and winter injury. I am growing apple trees from seeds, they are about 3 yrs old now in large pots. The disease starts out as small brown spots on the apple, which then get bigger as the apple grows. The disease appears through the wilt and the brunification of the leaves. Trees grown in poorly drained soils. Trees damaged by drought stress or waterlogged soils are more likely to be affected by black rot, including: Apple trees grown on sandy soils without supplemental irrigation. ), are susceptible to many diseases.The good news is that these diseases are often preventable and, even when they aren't, often cause damage mainly on an aesthetic level. The spots turn brown and then turn black. The fungus lives through the cold season in the dead bark and the infected apples that stay on the tree. The black rot and frogeye leaf spot fungus, Diplodia seriata (Botryosphaeria obtuse syn), covers a wide geographical range, attacking the fruit, leaves, and bark of apple trees and other pomaceous plants. Types of Heart Rot When you notice tree rot, then your tree has been attacked by a fungus. and other plants in the rose family, like hawthorns (Crataegus spp. White rot, also called bot rot (Botryosphaeria dothidea) is a fungus that affects apple fruit and wood with small circular spots that eventually turn orange and peel from the tree. Trees infected by fire blight often later develop black rot. Black rot is a fungus appearing on the apples when they are ready to harvest. Trees that are not irrigated during particularly dry spells. Phytophthora crown rot on a young apple tree. This fungus can cause severe problems to late-season fruit, so you should apply organic fungicides from the spring on if you expect it to be an issue.