Frog-Eye Leaf spot

[diltree]

I looked at a small flowering crab today that was exhibiting blotches on the leafs. If you flipped the leaf over, you could see the other side of the blotch swelled out and had little yellow hairs coming out of the bulge. I'm familiar with apple scab and I have ruled it out. Is this a case of "frog eye leaf spot", I really need a second and third opinion from one of the many great arborists here on arborist site. I wont diagnose a problem unless I'm 100% sure i know whats wrong. Also are there any treatments for this problem??



www.dillontree.com

 

[alanarbor]

I looked at a small flowering crab today that was exhibiting blotches on the leafs. If you flipped the leaf over, you could see the other side of the blotch swelled out and had little yellow hairs coming out of the bulge. I'm familiar with apple scab and I have ruled it out. Is this a case of "frog eye leaf spot", I really need a second and third opinion from one of the many great arborists here on arborist site. I wont diagnose a problem unless I'm 100% sure i know whats wrong. Also are there any treatments for this problem??



www.dillontree.com

I think you'd be looking at cedar-apple rust.

Cedar apple rust

Fungicides will control it, but must be done in the spring as the leaves are coming out. Right now, nothing to do.

Juniper is an alternate host, if there is a juniper nearby, removing it will reduce the incidence of disease. Sanitation by removing dropped leaves will reduce the inoculum on site. It is important to consider that resistant varieties are availible if this is an old crabapple, even rigorous spraying will be only moderately effective.

 

[woodville]

Rust, scab, spot It really doesn't matter what strain of fungi it is on any crabapple thay are all treated the same way at the same time.

 

[woodville]

Diltree, it sounds like a rare case of Sycamore - Anthracnose, but without a picture of the leaf, I cannot identify for sure. It could also be a rare case of Dutch Elm Disease. Is that common in your geography?

I don't think the way Dilltree described the issue has any similarity to anthranose nor is Dutch Elm Disease even possible in a Malus.

 

[diltree]

sounds like a toss up between cedar apple rust and dutch elms disease....thanks guys


www.dillontree.com

 

[Urban Forester]

DED in Malus??? If it has hairs coming out the underside it Cedar-Apple Rust. Apple scab is very different fungus that does not grow in that manner.