Apple Scab

What is apple scab? Apple scab is a disease to Malus trees (apple and crabapple trees). This disease is caused by the ascomycete fungus Venturia inaequalis. I know you are thinking...WHAT? When we think of apple scab in Michigan we think of an apple that has the brownish black dents in them or the crabapples that look bare and sickly by mid-July. But, apple scab is much more than this. Apple scab can affect tree leaves, buds or fruits. This disease is not a serious threat to these plants. However, if the tree is infected numerous times it may become very weak and become more susceptible to other insect or disease pests.

Apple Scab is dependent on cool, wet weather and infects tree leaves in the spring. In the late summer to early fall, apple scab infections can produce secondary spores and create new infections which will continue to infect the tree during wet periods. Wind and rain carry apple scab spores from infected leaves to new growth on nearby trees where new infections begin.

Owen Tree Service offers fungicide treatments to ensure your trees will be protected from apple scab. If you think you may have an apple scab problem give Owen Tree Service a call. Fungicide treatments are applied as new leaves are developing in the early spring. These treatments are started in April and continue through early June to ensure your chance of having apple scab is minimal. Apple scab not only ruins perfectly good apples it also takes away the beauty of your ornamental crabapple trees. When crabapple leaves start turning a dingy brown, black color it’s hard to admire the beauty of these ornamental trees. We spend tons of money making sure our yards, trees, and plants look stunning, so why take the chance of having your crabapple trees bare for half of the summer.