Geneva Rootstock Bark


#1

During the summer, I’ve noticed that the bark around my 3 year old apple trees is cracking and peeling. All four trees have Geneva rootstock: Zystar G-11, Goldrush G-11, Liberty G-16, and Enterprise G-41. Any ideas what the cause of this is? Is this detrimental to my trees? Does anyone else have this issue? What should I do?
Thanks for your help.


#2

I’d call that normal. Nothing to do.


#3

My Geneva rootstocks g30, g11, and g41 have all done the same. The cracks seemed to serve as an entry point for fireblight on two trees, killing them. Wish I knew some preventative action I could take.


#4

I doubt that those type cracks are an entry point for fb. That’s just the outer bark cracking and peeling off. There is a full compliment of intact bark underneath. The outer bark on most trees cracks in one form or another. It just looks different. Most of the Geneva rootstocks are fb resistant.


#5

It was a brutal year for fireblight here, with the wettest spring in years. Resistant varieties like Goldrush suffered mightily, despite the trees being pruned to a very open style, quickly pruning out strikes and sterilizing in-between, and very little nitrogen.

The reason I went with G30 a few years ago was its fireblight resistance. Nevertheless, I think it was fireblight that killed two trees on g30 this year. Here’s a picture of one of them right after I cut it down. My toes are right at the swelling where the graft was, and the bark cracked, and this canker appeared. If this is not fireblight, can somebody tell me what it was? Im pretty sure it was not collar rot, which I’m unfortunately also familiar with.


#6

Haldog, that looks nasty! It’s funny that also this year the only tree I have that had a possible fireblight strike was also my Goldrush on Geneva. The strike was not by the graft, but on some fairly new growth and I was able to prune it out without losing the tree. I also bought my trees with fireblight resistance in mind. I’m relieved to hear from Fruitnut that my bark split may be something not to worry about. One thing off my list of worries.Thanks.


#7

The bark that’s splitting and sluffing off is like our skin cells that sluff off. There’s live intact skin underneath.


#8

I have had many G-something roots looking like that. They might be a bit more prone to FB infection right after a piece of bark comes off as the under-bark is thin at that point. Kind of like how a crab is vulnerable when it sheds its old shell to grow a bigger one. My recollection is I have gotten a few strikes at the flaking bark area, but not a plague of them.

@haldog, that looks like fireblight.


#9

I have four Geneva apple rootstocks that did the same thing last year. We had 5" of rain in about three to four day period after a 6-7 week drought period. The Geneva rootstocks were the only rootstocks out of the 28 other apple trees( basically the same age as the Geneva rootstocks) did split or crack. The rest of my apple rootstock varieties that were not Geneva rootstocks did NOT split or crack. Actually the rain did not affect rest of the apple rootstocks at all. They looked fine.
I do not believe it is fireblight. I contacted Cummins Nursery and sent them pictures. I received two different answers from them.

  1. paint the tree with white wash to protect it from the sun
  2. wrap the tree with some burlap mesh to protect it from the sun

Neither answers seemed correct. Cummins said these trees would either recover or slowly die in a few years. They never did answer why the rootstocks split and cracked like that. Comforting!

I will not buy any more Geneva rootstock products. I do not want any more trees to end up like this.


#10

Mike that sounds different than what is in the above pictures and what I saw on my trees. On my trees it was dead bark flaking off; there was always young bark underneath when it flaked off. Your problem sounds like there was an actual split in the wood with “wet wood” out in the open. I never saw that on my trees.

In any case what you have doesn’t sound good. Any time you get a “new, improved” rootstock be prepared for downsides that have not been consistently observed yet. I still buy Geneva stocks but I don’t prefer them.


#11

Mine actually look like the pictures. I just have never had any fruit trees I have been growing ever do this over the 40+ years of growing fruit. The only trees to have done this are the Gevena varieties. I will see if these trees survive. I did use different rootstocks and start replacing those particular varieties with stock from other nurseries. I hate to lose these trees 3-4 years from now and not have started a replacement program to enjoy the apples I have on the Geneva rootstocks. I appreciate your reply.


#12

As Scott said the pictures in post 1 are just old dead bark flaking off. Can you show us a picture of the live bark splits?


#13

I am not sure how to post pics here. I do not see a link to attach a picture.


#14

@MikeC
When you reply, you’ll see several symbols right under your handle name. Click on the symbol that has an arrow up on top of a line. It’s the picture link.


#15

Here’s a couple pictures of the inside. It’s getting a little dark. I’m not able to pull back the bark. Everything is stiff and hard and would snap if I pulled it back. This is the picture of my Goldrush.


#16

I have two trees on G935 that are doing the same thing, cracking with very young green tissue underneath.

Could it be incompatibility or a virus issue?


#17

I don’t know what it is but I would guess that it is FB. I have had a few trees with the bark peeling and I was concerned that borers was causing it. I sprayed it a few times with neem/water. The trees survived and once the bark adjusted to being exposed they look okay. In my case I think they just needed a little time to adjust to the rapid change in bark. Most all my trees are on M111/Bud9 which is suppose to have some FB resistance. I had a few FB strikes this year but as of now none got into the roots.


#18

That stiff hard stuff is dead bark. Bark dies and peels off. The light brown stuff underneath is healthy live bark. There are a couple of minor cracks in the live bark. But I still don’t see anything to be concerned about.

The same thing happens on grapes. They peel off huge strips of dead bark. Underneath is smooth live bark that looks very much like those apples.


#19

Here are the few rootstocks I have that are Geneva variety. My question is why would I get fireblight in just the four Geneva rootstocks right after we had 5" of rain in a few days time? The rain was in in late August. Why would just the same area of each tree get the “fireblight”? Fireblight gets black, these were just like that area was swollen and the bark cracked or split not blistered.
These pictures I just took today. the other pictures I took were when it happened last year and are on my phone. I have to figure out how to get those downloaded to my computer then post them here. My trees last year looked just like the pictures bchiker has taken.


#20

Because most of what I’m seeing isn’t FB. POst 19 pictures are more complicated. I do think there is a couple areas where the bark has been damaged. Could it be FB, maybe, but it could also be physical damage.

IMO the stuff going on in post 1 pictures isn’t FB.