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[John Barbowski <jbarbowski@gmail.com>]

More anecdotal and layman's evidence - but -

When I started summer pruning 5 years ago on my three semi-dwarf trees (Mac, R Del and G Del), I believe I reduced my pruning effort by about 50% compared to the normal dormant pruning in previous years. Each winter, I used to take out around 15-20% of the trees, only to have it grow back in the summer - also with minimal apple production. Am I way off base to suggest that the energy stored in the roots of a dormant pruned tree provided that extra burst to stimlate the tree back to what it considered normality?

My idea of a good tree is one that has minimal vegetative production with maximum apple production; namely, less work pruning, more satisfaction imbibing. To get to that state is probably a real art, combining both knowledge and practical experience. (and listening to the discourse by those more knowledgeable and extracting pertinent points that are appropriate to one's environment).

Opening up the canopy allows more light. But would the remaining vegetation absorb a large amount of that light for extra nutrient production and storage? Would the leaves not already be at or close to their maximum absorption capacity? My thought is that there is a reduction of the trees capacity, thereby reducing ultimate vigor. Any new growth late in the season should not offset that which was removed. And if the apple were bearing a reasonable crop of fruit, the new growth would be minimal as the nutrients would be mostly directed to the fruit.

With summer and Lorette systems, you want to stimulate the production of additional fruiting buds. If successful, the increase in these energy hogs would result in a less vegetative tree - and hopefully an equilibrium between veg and fruit. At the same time, the tree is under control. (we hope)

Different trees react differently to pruning techniques in different locales. One must find the appropriate principle for his needs. This is where the real difficulty lies.

With my experience in dormant pruning, I will not be using that method in the near future.


john b

On Thu, Aug 13, 2009 at 8:24 AM, Alan Haigh <alandhaigh@gmail.com> wrote:

My take on whether or not summer pruning will be dwarfing is that if you actually substantially reduce the amount of light harvested you will reduce growth.  If on the other hand you simply remove surplus harvesting capability, essentially reducing shading and enhancing efficiency, no dwarfing will occur.

 

  Sometimes I bring trees in and shrink their range but I would assume that this would be about equally dwarfing whether done winter of summer- at least in the long run.  That's because the ability to harvest that light is not recovered whether branches are pruned winter or summer.

 

One interesting question to me is where harvested energy goes, based on whether the wood is fruiting or vegetative.  Obviously spur leaves are going to send much more energy to fruit production then to new wood (the basis of vigor).  Trees start to slow down once they start bearing fruit but I used to think that annual wood (their leaves, actually) sent more energy to the roots (as well as to new wood) then spur-wood.  Ferree's research seems to contradict this assumption as his moderate summer pruning leaves spurs alone and only removes vegetative wood.  I believe that anything that sends more energy to the roots will increase a tree's vigor.