Return to the Fruit & Orchards Forum | Post a Follow-Up

 o
New tree with apple scab

Posted by sunnibel7 Md 7 (My Page) on
Thu, May 24, 12 at 12:08

(sorry for the long back story, if you want to skip to the question it is in the final paragrph)

This spring I bought two new apple trees on a semi-whim. Semi because I've been wanting to get started with fruit trees for a long time now, but whim because they were there, I was there and I bought them knowing that the reassurances I was getting that they were appropriate to this region might just be stretching things a little. I'm beginning to think of them as my sacrificial trees, here for me to learn from, but likely to be deceased before too long. One's a Fuji and one's a Gala.

So they are in the middle of a field, with the nearest other Malus about 1/3 of a mile away. They were breaking dormancy when I got them, and I did spray them once with a copper solution for cedar apple rust, but only once since we then went through a real long spell with no rain. Lately I noticed some dark growth on the leaves and then on the solo fruit set that I think is apple scab. One of the trees is horribly infested, like almost every leaf. Reading on scab says that it comes from last year's leaf litter, mainly.

So my question is did those trees come with this disease from the nursery? Or is it somewhere in my local environment at such a high pressure that it could cause such a bad infection so fast?


Follow-Up Postings:

 o
RE: New tree with apple scab

Could be either or- scab is a gypsy fungus and gets around long distances during periods of rain. That's why cultural controls like removing leaves at end of season only get you so far.

Immunox has good kick-back if the disease looks like it might really slow your tree down but by now it may be warming up enough that scab has bout completed its cycle.


 o
RE: New tree with apple scab

If they were breaking dormancy when you bought them, they probably didnt have leaves exposed, so the apple scab most likely came from a source at your home.

I wouldnt worry about it too much, leave them as is, and clean up ALL leaves in the fall. I did the same in the fall last year, and I have no scab so far this year.

-Eric
----------------------------------------------------


 o
RE: New tree with apple scab

If leaf removal was all that affective I suspect commercial growers would consistently blow leaves into a pile and burn or wash quick lime over them.


 o
RE: New tree with apple scab

I did say "so far"... :)
I picked up every single leaf off the ground and put down compost over the top of the ground.
Overwintering of the dropped infected leaf is the cause of spring/summer infection, remove the leaf, remove a majority of the problem.

-Eric
----------------------------------------------------


 o
RE: New tree with apple scab

Recently I saw a Sustainable Ag research project where super-cleanliness was successful with apple scab.

All three of our apples are resistant. The VA extension service says resistant varieties are the only hope in the humid mid-Atlantic.


 o
RE: New tree with apple scab

Planatus, I am surprised to hear that. I have almost no scab in the mid-atlantic and always considered it a more northern disease, our hot summers bake it out. Maybe you are more in the mountains, I see you are in a colder zone than I am. I never spray for it and only one year have I had any scab to speak of.

Re: the original question, I don't see any reason why it could not be on the bark and in the buds. New trees are very susceptible since they are weaker, so only a small amount of scab could go a long ways. Most of the scab overwinters on the leaves since thats where it mostly was, but it could easily shed onto bark etc. Your scab also could have blown in, the original source could have been miles away.

Scott


 o
RE: New tree with apple scab

So, barring death of the tree(s), would extreme cleanliness at the end of the year perhaps ameliorate this? I guess this is a good introduction to the apple diseases in my area... I wish there was a way to sample some of the various other apples that are offered as being more suitable for here. It's hard to say "I want to grow a Liberty or William's Pride" when I don't know what they taste like. A small aside, growing up in Upstate NY we used to find old remnants of orchards everywhere and it was great fun sampling all of the different apples. Sweet ones, tart ones, bitter ones, insipid ones... Some would be so amazing.


 o
RE: New tree with apple scab

I haven't seen the research mentioned above but I would guess that if leaf removal was to be successful you'd need to be in a location where there weren't untended diseased apples nearby. I'd like to see that research to see how far the researched trees were from outside contamination- that would mean everything. However for a homeowner I don't see any reason not to go ahead and be as sanitary as possible.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Fruit & Orchards Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here