I bought a few trees on Emla7, which I understand is the virus free version of m7.
For me, they break off at the graft union in our high winds. I think I’ve lost about 5 trees this season because of this. I lost three last night. Here is a pic of one.
What variety of apple? I havent had issues with my M7 trees. Sometimes I honestly believe it has something to do with how the tree was grafted as well, in terms of a bench type graft or T budded.
Last night I lost a Pristine, Blondee and my only Golden nugget. I thought the Golden Nugget was on EMLA7, but actually it was on G11. One of the other trees which snapped at the union earlier this summer was also on G11.
The graft union must be a weak point on some of these rootstock/scion combinations. I’ve never seen a peach break at the union.
My issue with M7 over the years has never been graft incompatibility, although I’ve had a G30 snap at a graft union, which I assumed was a compatibility issue- now I’m not sure because 10 years later same variety on same rootstock is still going strong 30’ from the tree that snapped- and made it through hurricane winds without support. I assume that incompatibility would be consistent between any given cultivar and rootstock- but possibly it can be a reluctance to join tissues that is overcome with time.
The snap of my tree was smoother and cleaner than that in the photo, as I recall. The trees problem in the photo may be a disease issue from the looks of it.
What has been a consistent issue with M7 is poor anchoring, which I believe to be well understood in the world of commercial growing because it was often recommended a couple decades ago, when M7 was still the most used rootstock, that trees on it be planted with heavy metal electric conduit posts. In my experience and before that from what I read, M7 is at greatest danger of becoming dislodged from the soil the first couple of years it carries heavy crop. Eventually, at most sites with most scions, it stabilizes.
I have had a variety of apple trees on a variety of root stocks snap at the graft union in “hurricane force winds” AKA as regularly occurring winds on the Great Plains! Personally I think it is wise to stake any apple and pear tree in a area exposed to high winds until it is well established.
Perhaps that’s the issue, apples are just a little weaker at the union than other fruit trees? I’ve never seen this breakage with other fruit trees at the farm (peach, apricot, cherry, plum).
I suppose that is true to some extent, obviously though older trees on the more vigorous root stocks dont need support at some point. At least I have never seen a 30’ tall tree snap off at the graft union!
Were those two G11 trees that snapped staked or trellised somehow? From what I’ve read they’re not really supposed to be free-standing trees.
I have three G16 (similar sized to G11) trees that I haven’t staked, but they’ve only been in our ground for 5 months. Some say G16 trees anchor pretty well, but I’ll feel better if they’re supported when they start producing.
We also have four M7’s, one of which is a Pristine! Hope I don’t have the same result as you…
Subdood,
They weren’t supported. I know some of these rootstocks recommend support because anchorage can be poor, but none of these trees blew over. They all snapped off.
Olpea,
I’ve had bad luck with most apple rootstocks that are not mm111 or Antonovka. High winds, clay / loam soil, drought, excess water etc. are all normal conditions in Kansas. 111 is great rootstock. The apple trees I got this year did not do very well for the above mentioned reasons.
Horne Creek Farm is having a lot of trouble with their M7 trees tipping over due to the layer of hardpan 18" deep from 150 years of moldboard plowing, which compacts the subsoil. Deep ripping in such instances is needed before planting , not much can be done now other than re-planting with vigorous rootstocks. I got tired of the suckering and lack of vigor in our M7 trees and use M111 now.
I have a similar situation at a former dairy farm, only it was hooves that compacted the clay loam. 7 year old trees would tip and not from the load of crop. It would mostly happen in late fall when the soil would become wet and heavy winds would knock the trees over. I decided to prop tress up and stake them then I would bring about a quarter yard of sand and compost mix and spread it annually under the branch spread. I figured it would eventually create enough ballast to support the trees. It took several years but the stakes are no longer necessary.
