I have a Late Duke cherry on Krymsk 5 rootstock. Dukes are tart/sweet hybrids. I planted it last year and it did okay until the middle of the Summer. I then noticed the leaves yellowing on their margins. As time passed the entire leaf would turn yellow. The entire tree was effected. The Krymsk rootstock had suckered and for awhile the only green leaves were the leaves on the sucker.
The tree leafed out normally this year and looked good until around 7/3/2021 when I noticed the margins of the leaves started yellowing again. It was after some heavy rains. I have tart and sweet cherries nearby on various rootstocks including Krymsk 5 and none of them show these symptoms- all of them look completely normal.
Here are some pictures that I took today 7/30/2021-
A picture of the leaves of the Krymsk 5 rootstock sucker.
I have considered several possibilities.
Captan spray burn
I don’t think this is the problem since no other cherries are effected and the last Captan spray was 5/30/2021.
Too much fertilizer
I think this was a possibility the first year but this year I was pretty careful and I fertilize fairly early in the Spring so I think this is also unlikely.
Virus in the tree
I think this is a possibility. I contacted @JamesN . He bought the exact same cultivar/rootstock combination from the same supplier in the same year I did. His tree shows no symptoms like my tree. However, his climate is very different and probably less stressful than mine.
Some type of root disease
I haven’t done any digging to inspect the roots yet. I wouldn’t think it would explain why the rootstock sucker is less effected but who knows.
So at this point I am looking for ideas as to what is causing this. Any suggestions would be appreciated.