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Slope affects on apple tree vigor

Posted by Eliza Greenman 
Slope affects on apple tree vigor
October 23, 2014 12:21PM


This photo shows the flush of late season growth (bright green) in the South-facing orchard at Foggy Ridge. I've decided to use fall flush as a visual indicator for tree vigor. For a heavy soil which receive a lot of rain (Appalachia Southwestern VA), I'm starting to believe that slope matters when you’re planting very vigorous varieties (v^3) of apples (and most cider apples on this site with exception of Dabinett and Roxbury Russet seem to have high vigor). Vigor isn’t a good thing in my mind, at least not for apple production in the South. The tremendous amount of vegetative growth this orchard gets makes the trees more susceptible to fireblight and reduces the fruiting potential by putting more energy into veg growth over fruit growth. I want to learn how to better control vigor in order to more organically reduce pressure from fireblight and lack of fruit (there are antibiotics and black magic sprays that address these issues in a conventional orchard).

Check out this picture above: I know it’s a bad picture (I could really use a cool drone for this sort of thing), but you can see the green flush of the upper NE corner and how there is a lot more growth on those trees than the rest. I decided to look at the web soil survey (through NRCS) this morning to see if the soil map complements my theory that slope and aspect (but mostly slope) do have an important effect on tree vigor.

This is what I found!




You see! The difference between a “sloping” loam and a “steep loam” is totally corroborated in the picture that I took.

So what does this mean?

It seems like everyone in permaculture is on the “plant on contour,” “swale,” or “keyline” kick. I’m here to remind everyone that no site is the same. We have a rocky silty loam that is clay-rich after 7 inches down. We get a lot of rain. We have problems with too much vegetative growth and not enough fruit bud growth. Swaling, contour plantings and keyline are silver bullets for certain areas, but not here in Southwestern Virginia where I believe it would cause INSANE vigor that would reduce our crop and increase susceptibility to disease.

Of course, rootstock and variety selections matter as well, and I’m mostly talking about heirloom varieties here which tend to be more vigorous anyway. If you live in an area that has heavy soils, a decent amount of rain, and want to plant fruit trees, I ask you to keep tree vigor in the back of your head. Steep slopes where water isn’t given an opportunity to slowly seep into the soil…might be worth the thought.



Edited 1 time(s). Last edit at 10/23/2014 09:52PM by Eliza Greenman.
Re: Slope affects on apple tree vigor
November 02, 2014 09:18PM
A couple questions--how is the groundcover managed? And do you add any fertility amendments?

Hemlock Grove Farm
Zone 5 in New York
Re: Slope affects on apple tree vigor
November 03, 2014 11:30AM
Hi Eliza,

I am also interested in this topic. Please continue with additional details, as you get them together. I have a portion of our apples on contour/swale plantings and appreciate the potential relevance you are addressing.

Here in the Sierra Foothills of CA, we do not receive much summer rainfall, but I am able to irrigate as needed.

Your statement that "no site is the same" is absolutely correct. Especially when coupled with each growers style, philosophy, ability and willingness to address various issues, within the orchard, and you have a guarantee that one size will not fit all.

Thanks for the photos too!

Gopher Hill Apples
Zone 8 in California
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