CRABAPPLES LOSING LEAVES?

A common ornamental tree disease arborist’s encounter in Michigan is apple scab. This foliar disease infects crabapple leaves in the spring, but does not make itself apparent until later in the summer. After the apple scab fungus has infected enough of the crabapple leaf the leaf will fall from the tree.

Crabapple trees infected with apple scab usually start to show the effects of the disease between mid-June and early July. By August some crabapple trees may have even lost most of their leaves.

If your crabapple tree has lost a lot of its leaves from apple scab it is really not worth spraying the tree with a fungicide at this time. The disease is already in the leaf tissue and further apple scab infection is not going to be significant in the warmer and drier months of the year. Make sure the tree is receiving ample water and you may want to consider fertilizing in the fall to assure adequate nutrients are available to the tree.

The best way to prevent apple scab in the future is to apply a foliar fungicide spray in the early spring. Crabapple spraying for apple scab should start soon after the leaves begin to emerge. A couple follow up treatments will give you the best level of control.

To learn more about controlling apple scab click here:
http://www.owentree.com/Apple_Scab.php

Apple scab infection

 

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.

APPLE SCAB CONTROL

Apple scab is a frequent problem for any Lapeer, MI landscapes with crabapple trees. The apple scab fungus may be found growing on the crabapple fruit itself, the leaf, leaf and fruit stems, or the green twigs of the crabapple. I’m surprised at how many Lapeer homeowners I speak with that are unaware that apple scab is a tree disease that can be controlled with the right treatments.

Apple scab is easy to diagnose, especially if it is on the leaves or the fruit of your crabapple tree. Anyone with a computer can find numerous photos of apple scab infected leaves and confirm that their crabapple tree has apple scab.

As a resident of Lapeer I see numerous examples of crabapple trees infected with apple scab fungus. Apple scab is caused by the fungus Venturia inaequalis, which also can affect apple, hawthorn, mountain ash, and firethorn. Because apple scab is a fungal disease, fungicides are used to control it. Apple scab can be hard to prevent if fungicide treatments are not started at the right time. To control primary infections you want to start the fungicide program shortly after the crabapples start to leaf out, which is usually around mid-April in Lapeer. I’ve found that the best control of apple scab is obtained when at least three fungicide treatments are applies throughout the spring.

Apple scab spores are always present in our environment, so it would be necessary to have these fungicide treatments applied every spring. If you need more information on apple scab call us at 800-724-6680 or you can find out more information about apple scab at: http://www.owentree.com/apple_scab.html