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. Brown Rot – This is the most serious version. Apple trees (Malus spp.) Phytophthora crown rot on a young apple tree. It occurs where the apples have had physical damage. The disease starts out as small brown spots on the apple, which then get bigger as the apple grows. Remove the soil from around the trunk and look at the crown. 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. 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. Black rot is a fungus appearing on the apples when they are ready to harvest. It causes your tree to decay, dry out, and crumble into pieces. 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. Black rot can stress an apple tree if it strikes the tree year after year, robbing it of leaves and nutrients. Trees that are not irrigated during particularly dry spells. This fungus gets into plum and apple trees through wounds in bark caused by insects, natural stressors, and/or improper pruning. Peel back the bark from the trunk. Bitter Rot. The spots turn brown and then turn black. However, fungi do not always produce fruiting bodies, and fruiting bodies occur less commonly on certain fruit tree … 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 grown in poorly drained soils. 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. I am growing apple trees from seeds, they are about 3 yrs old now in large pots. and other plants in the rose family, like hawthorns (Crataegus spp. Types of Heart Rot When you notice tree rot, then your tree has been attacked by a fungus. The disease appears through the wilt and the brunification of the leaves. 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. Trees infected by fire blight often later develop black rot. Photo by William M. Brown Jr., Bugwood.org via CC 3.0. This can manifest in the following three ways. Apple tree root rot produced by the funguses from the Phytophthora Genus. Your tree may have an obvious decline that could be due to many factors, including fire blight and winter injury. In the basal area of the trunk appears similar lesions with those produced by the crown gall. The trees have the growth slows and dry prematurely. ), 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. 1, 2). The fungus lives through the cold season in the dead bark and the infected apples that stay on the tree. The fungus gets into the apple tree originally via open wounds in the tree from broken branches and cracks in the trunk.