Here's another picture of the back of the leave! It does not look natural!

Cedar apple rust. There are lots of prior posts on the subject. Basically you need to spray next spring before infection.

It looks something the pictures I was seeing of Cedar Apple Rust. A strange fungal organism that live and develops for part of its life cycle on cedar trees, and part of its life cycle on apple trees. If you think it looks unnatural on your apple tree, you should see what it can look like on a cedar tree ... Like something out of a H.P. Lovecraft story.

{{gwi:122769}}

This post was edited by bob_cville on Thu, Aug 21, 14 at 14:00

Thanks for the inputs. What should I use for spray and what's the right time for doing that?

On a side note, if I do not spray, would this disease have any effect on next year crop?

Are the galls on the cedar tree hard and hollow? Can they live in woodchips or scrap juniper leaves or stumps? I ask because I have seen a couple of single pods poking up through my woodchips this year that look like CAR. I have a couple of leaves on my Bella apple that look like the original poster's pics.

Thanks.

bob_cville,

I have no clue that the cedar rust looks that horrid! For not knowing, I would thought that's some sort of fruit from the tree!

If infection is bad enough it will defoliate the apple tree and reduce the crop. There are big differences in apple cultivar susceptibility, see table 2 below.

Here is a link that might be useful: Cornell fact sheet on CAR

Reading more on the CAR from the forum, now that I know I need to treat it with Immunox at pedals fall.

Two more sprays that confused me:

1. Triazicide for what disease and when?
2. Neem Oil?

Can someone with knowledge help clarify my confusion? Thanks.

Tom

Triazicide is an insecticide for coddlng moth and other insect pests. Neem oil is for both insects and disease but I'm not sure how effective it is or all the pests it controls.

Hi, I have three crabapple trees that have been plagues with CAR for the past four years. Finally after sprays of Immunox and Monterey Fungi Fighter, the CAR is finally disappearing. I spray the Monterey in the spring, mid-summer and late summer. I also spray them with a combo of a turbo sticker spray, immunox and triazicide every three weeks during the summer. I stop these sprays in September.

tomIL: just what MrsG said...Immunox (myclobutanil). I mix myclobutanil with sulfur and have managed to stop and in fact; turn around a case of CAR on my Goldrush. The immunox is systemic and I think the addition of sulfur to the mix aides greatly in the effectiveness of the individual components. I think this because I tried each individually for a while with less than acceptable results.