Apple trees are one of the most common types of fruit trees found in home gardens, but they come with more than their fair share of problems. That’s due to the fact that apple trees are prone to experience a wide variety of diseases, some of which are directly connected to pests that frequently attack the fruits, vascular tissues, and leaves of plants. To protect your precious apple trees from pests, diseases, and premature death, consider safeguarding your trees by implementing better pest and disease control measures.
Common Types of Diseases Affecting Apple Trees
Many diseases manifest themselves through the resulting rot affecting the fruit of an apple tree. In addition, gardeners may notice leaves that are wilted or discolored, or trees that are generally unhealthy in appearance. These diseases usually occur when bacteria or fungus enter wounds created on the surface of fruits, leaves or other parts of the tree due to the activity of pests such as the leafhopper, thrips, Japanese beetles or flatheaded apple tree borers.
Below are five of the most common apple tree diseases. Though your tree’s susceptibility is largely dependent on the location in which you live, presence of plant pests, sanitation, and the season, by reading this article you will be more prepared to handle the diseases if and when they become an issue within your garden.
This disease affects both the fruit and leaves of the apple plant. It occurs as spores resulting from leaves infected with
apple scab fungus travel through the air and infect the buds of the plants. The infected plant tissue results in misshapen fruits and black spots or legions about ¾ inches wide. Proper sanitation helps control the spread of this disease.
Black Rot and Frogeye Leaf Spot
Like many other apple tree diseases, Black Rot and Frogeye Leaf Spot disease can affect trees by entering through the wounds inflicted by insects. Once a fruit has a wound and the fungus called Botryosphaeria obtuse is present in the environment of your garden, the fungus enters the epidermis of the plant cells, resulting in shriveled, blackened apples that are not fit for consumption. By controlling plant-eating pests in your garden, you can prevent black rot from occurring.
Crown Gall Disease
Crown Gall affects the crown of trees, i.e. structures above-ground that include leaves, branches, and stems. It also affects the roots of the trees. When the disease occurs, wart-like structures begin to cover roots, stems, and branches, disrupting the tree’s supply of nutrients. The bacteria causing this disease will usually enter the plant through damaged or wounds root-dwelling insects inflict. These insects may include microscopic worms called nematodes which feed on the roots of many plants. To reduce your apple tree’s risk of getting this disease, avoid planting infected nursery stock and apply nematode pest control measures that include reduction in moisture levels within the soil or the use of insecticides.
This disease can easily spread through the activities of ants, bees, numerous kinds of flies and other insects. Erwinia amylovora, the bacterium causing the disease, spreads from one blossom to another or to shoots as the insects make contact with these parts of the infected plants. The bacterium may also spread when plant-feeding insects with
piercing mouthparts, for instance leafhoppers, aphids or lygus bugs, wound plant structures. To prevent cankers and other symptoms of the disease from occurring, apply disease control measures that include the use of copper-based products on open blossoms, as well as biological control to prevent pest infestation.
Moldy Core of Apple
Moldy Core of Apple disease affects a variety of apple trees and is often not obvious until a mature apple is cut. The disease results in a moldy core that is brownish-yellow or whitish in color and occurs due to the presence of fungi which enters the plant via its blossoms when they open. The disease may also occur when pests such as codling moths, also known as apple maggots, burrow into fruits and feed on its core while in their larval stages. Susceptible apple tree varieties like Red Delicious can be protected by employing pruning and other practices to reduce moisture on plant surfaces. You may also consider using fungicides or apply pest control measures to reduce codling moth infestation.