Brown leaves on apple trees - Ask Extension
Hello. These photos are from my mature (40 years old) Gravenstein apple tree. The tree is laden with apples, but some of the small branches have brown...
Knowledgebase
Brown leaves on apple trees #837606
Asked June 26, 2023, 1:09 PM EDT
Hello. These photos are from my mature (40 years old) Gravenstein apple tree. The tree is laden with apples, but some of the small branches have brown, withered leaves. What could be causing this? It's happening on other trees, too -- Liberty, Gala. Thank you.
Josephine County Oregon
Expert Response
Hi Liz:
It is difficult to tell from the pictures exactly what is causing the leaves to turn brown. I have a few questions for you.
Have you been able to inspect the clusters of dead leaves for pests or spores on the under side of the leaves?
Are the clusters of leaves detached from the tree from the weight of fruit? I know everyone has a very heavy set this yet, perhaps it is self pruning?
Did this happen after our couple of frosty nights, frost damage perhaps?
Any damage to the trunks or root structure of the affected trees?
A closer picture of the damaged leaves would be helpful in trying to determine the cause.
Thank you,
It is difficult to tell from the pictures exactly what is causing the leaves to turn brown. I have a few questions for you.
Have you been able to inspect the clusters of dead leaves for pests or spores on the under side of the leaves?
Are the clusters of leaves detached from the tree from the weight of fruit? I know everyone has a very heavy set this yet, perhaps it is self pruning?
Did this happen after our couple of frosty nights, frost damage perhaps?
Any damage to the trunks or root structure of the affected trees?
A closer picture of the damaged leaves would be helpful in trying to determine the cause.
Thank you,
Cristi,
I'm attaching some closeups that show examples of the affected leaves. My untrained eye doesn't see any spores or insect activity on the undersides of the leaves. I don't see any correlation between weight of the fruit and the brown leaves. I don't think this happened after the frosty nights -- I think it happened later in the season -- but I'm not certain. Everything else about this quite mature tree looks healthy, including lots of suckers growing out from the base of the trunk (which I try to keep on top of)!
Thank you so much for looking into this.
Liz
Hi Liz:
I am stymied too! Generally fire blight would be my first thought. But from what you have told be about the health of the tree, it doesn't line up. I'm going to send you an informational article on that disease and how to treat it.
Fire Blight
As for the root suckers, you probably already are aware that they compete with the main tree for water and nutrients. They also are a prime feeding site for woolly apple aphids and they are a potential entry point for fire blight. So do keep up with the control of them. Another article that lists all common pests and diseases of the apple tree, just in case you are curious.
Diseases and Pest of the Apple Tree
As it is an older tree, proper pruning, watering and fertilizing will contribute to it's health and lessen it's susceptibility to pests and disease. The article below speaks to successful varieties to plant in Central Oregon. It also has links to further articles on pruning and general fruit orchard care.
Selecting Fruit Tree Varieties for Central Oregon Home Orchards
I would do my best to prune out the affected areas and remove from the area.
All the best to you,
I am stymied too! Generally fire blight would be my first thought. But from what you have told be about the health of the tree, it doesn't line up. I'm going to send you an informational article on that disease and how to treat it.
Fire Blight
As for the root suckers, you probably already are aware that they compete with the main tree for water and nutrients. They also are a prime feeding site for woolly apple aphids and they are a potential entry point for fire blight. So do keep up with the control of them. Another article that lists all common pests and diseases of the apple tree, just in case you are curious.
Diseases and Pest of the Apple Tree
As it is an older tree, proper pruning, watering and fertilizing will contribute to it's health and lessen it's susceptibility to pests and disease. The article below speaks to successful varieties to plant in Central Oregon. It also has links to further articles on pruning and general fruit orchard care.
Selecting Fruit Tree Varieties for Central Oregon Home Orchards
I would do my best to prune out the affected areas and remove from the area.
All the best to you,
Cristi,
Thanks so much for this comprehensive reply. I looked at the link you sent, and based on the photos I saw there, this tree definitely has fire blight!! I will get out my ladder and remove the affected parts that I haven't so far been able to reach. Not sure about spraying it, as I don't have a relationship with anyone who does that, plus the fruit is developing well so I might take my chances and forgo that.
Attached is a photo of a fellow that I found on my Gala apple tree. Is he cause for concern??
Thanks for your work and help.
Have an enjoyable week.
Liz
Hi Liz:
Glad I could help. This looks like a Tussock Moth caterpillar. I wouldn't bother with him, his hairs can be irritating to the skin and eyes. I've attached more information, so you can see the signs of eggs sacs and remove before an infestion occurs. They are usually kept under control by natural predators.
Tussock Moth
Have a great day,
Glad I could help. This looks like a Tussock Moth caterpillar. I wouldn't bother with him, his hairs can be irritating to the skin and eyes. I've attached more information, so you can see the signs of eggs sacs and remove before an infestion occurs. They are usually kept under control by natural predators.
Tussock Moth
Have a great day,
