Diseases Diseases

Most Common Apple Tree Diseases

Published at 03/12/2012 04:44:45


The apple tree can be subjected to a multitude of different apple tree diseases that can have an effect both on the fruit and tree. 


Apple scab is one of the most prevalent of the apple tree disease, and it affects a vast portion of the tree. It can infect the new growth, foliage, flowers/blossoms and fruit. This apple tree disease usually manifests around early mid-spring, especially when there has been a high level of rainfall. The fungus that causes the manifestation of this disease is Venturia inqequalis. The fungus resides in leafs that have fallen over the Autumn/winter months. During the spring months spores are released, which are blown onto the healthy new leaves that the apple tree has produced.

There are palpable signs that your tree has contracted apple scab, these are small, olive-colored lesions on the undersides of the leaves, a defoliated tree, and young leaves will become curled and distorted. Additionally, the apple trees fruit will be of a smaller size, and the fruit will develop black or brown scabs on the surface area. To prevent your apple tree from acquiring this disease, be sure to rake the surrounding leaves and debris, and then dispose of them. Additionally you can spray the infected tree with a fungicide in early spring, such as lime sulfur, sulfur or captan. 



Fire Blight; This is a bacterial apple tree disease that can affect the blossoms, shoots, limbs, and, sometimes, entire trees. Fire blight is an extremely erratic and destructive variant of apple tree disease, thus making for an difficult and costly disease to control. The symptoms for Fire Blight are, depressed areas of discolored bark, cankers on tree limbs,wilting,dying and black blossom clusters, young shoots will wilt and become crooked, leaves will turn brown/black and wilt, and twigs and branches may turn brown or black. Fire Blight usually manifests around spring time, when it is warm with high moisture levels. There are a few procedures that you can undertake to both prevent Fire blight from occurring and to reduce the symptoms of Fire Blight. These include pruning affected areas of the tree, antibiotic sprays can help with affected blossoms, and if need be you may be required to remove the entire infected tree from your property to prevent it from spreading. 

The last of the apple tree diseases that we will discuss is Powdery Mildew. This apple disease is characterised by white-grayish spots on the underside of the leaves. These spots will have a fealty, talcum-powder like appearance and feel. Additionally the apple tree will have wilted leaves, stunted growth, and small black spots on the leaves and twigs. To prevent your tree from becoming infected make sure to plant it in a area that has good air flow, and to spray your trees with either myclobutanil, lime sulfur or sulfur.

Tips and comments

An easy way to prevent the appearance of a few of these apple tree diseases is to keep the tree and surrounding areas clean and clear of leaves/debris. These are only a few of the many apple tree diseases out there. Be sure to conduct your own research to determine what your tree has been infected with.