I’ve been checking my trees every couple days this summer and was shocked to see my peach tree, sour cherry tree and bushes as well as most apples had yellow leaves on their leaves nearest the trunk. At first I assumed apple scab but the leaves on the other trees look similar also when looking online the spots on my leaves dont match real well. Anyways I sprayed immunox at petal fall and then every week after for a total of 3 applications. From everything ive read i thought that was long enough? Should I be spraying fungicide until July?
For the apples, It’s probably Alternaria blotch, or Glomerella leaf spot, or this newer diseaseMarsoninna leaf blotch. Some varieties are more susceptible than others. In my climate Liberty seems basically immune, while Goldrush is particularly susceptible. Unfortunately Immunox is not very effective against these diseases.
Not sure about the apple tree but on the other trees it looks like bacterial leaf spot / shot. I have peach, nectarine and plum that have it and it looks the same as your pictures. The brown dots on leaves, sometimes the dots will fall out of the leaf causing the ‘shot’ / ‘hole’, and the leaves will suddenly turn yellow and soon after the tree will drop them.
I too thought it was fungal at first but fungicides did nothing for it the first year I had it. Supposedly the solution is to spray copper at maximum strength starting in the dormant season but my understanding is that it lives in small almost unnoticeable cankers on the trees so it can be quite hard to get rid of, but it is possible
Does it become a big deal for the tree? Can they still go on producing for a long time or do they eventually start to die off from it? I can add copper to the list of things I need to spray for…
Do you think it could be frog eye leaf spot? I did some more research and this looks pretty close to what my non yellowing leaves look like… my liberty seems healthy but I also just planted that this spring, all 15 or so other cultivers are infected to some degree… growing fruit is turning out to be a pretty frustrating hobby…
I think it depends on the tree. My peach and nectarines tolerate it very well and after more than 2 years with it it is not a big deal - a small number of their leaves are affected at any one time. If it didn’t have to treat my plum tree and wasn’t worried about it spread to other trees I could leave it go. My plum tree however defoliated 75% last year from it and has defoliated 50% this year thus far. If it wouldn’t eventually kill my plum it will affect its fruit production for sure
A Chinese study I saw contradicts this and I have good success against Mars. with a mix of myclo and Cap at highest rates first week of July and again a month later. Myclo has some kickback and long residual activity so I decided to run with it and I’m very glad I did. I’ve used it enough to be very confident of the treatment.
I haven’t checked the literature for a while but just a few years ago it was just guesses in this country. The thing is, it isn’t an issue in commercial production because in the east it is usually done by keeping active fungicide on the leavers throughout the season to prevent summer fungus.
I don’t follow that recipe either and have found that I can stop spraying in June and begin again in July if the goal is pristine fruit. This defies Cornell expertise.
After nearly defoliating last year, my Goldrush is getting a lot of one or more of those diseases, or something very similar, despite multiple myclo sprays. I didn’t use any Captan this year so perhaps that’s the key. Other apples are much less affected. Goldrush is the only one I have with Golden Delicious as a parent, so it may be some genetic susceptibility. The recent hot weather we’ve had seems to be accelerating the problem.
Have look here under Disease Management & Production Information (Residential) also Apple & Pear Diseases and Stone Fruit (Cherry, Peach, Plum) Diseases
There’s lots of info that applies to the Midwest region.
