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balanced crop load

Posted by Michael Phillips 
balanced crop load
June 01, 2020 06:42AM
The bees had a tremendously warm week to pollinate and now the crop awaits revealing. Bloom here was encouraging in that a number of last year's heavy bearers (like Sweet Sixteen) had enough blossoms this year to look promising. Of course there are trees still deep into a biennial funk (like Fortune) but not quite so many as in year's past. I'm pondering how biology and nutrition tie into a balanced crop load.

I came across another way of expressing thinning parameters on a UMass fruit fact sheet on Thinning Apples Chemically:
Fruit thinning is done to increase fruit size and enhance repeat bloom. The fewer fruit that are allowed to develop on a tree, the larger those fruit will be. In general, reduction in the number of fruit to 4 to 6 fruit per cm of limb circumference is required for good size. Good return bloom usually can be assured if fruit density is reduced to 8 to 10 fruit per cm within four weeks of bloom. Therefore, more severe thinning is required to obtain good fruit size than to get adequate return bloom.

I have not appreciated what potassium bicarbonate did to growing shoot tips when I tried the blossom thinning approach. The whole idea of using lime sulfur to "spray thin" just gives me the willies when I think of how important arboreal biology is in a holistic system. And so I will spend this next month handthinning as serendipity guides me to some vareities but not all. Application of photosynthetic bacteria (see Quantum Thinking) is part of the story of improved return bloom. The trees seem to be telling me that a righteous nutrient program helps here too, not just with meristem development for next year's crop, but with balancing crop load in the current year. Wouldn't that be an amazing gift? And why not? Biology and healthy plant metabolism have gotten us this far.

Consider this a purely speculative post awaiting a community conversation.

Lost Nation Orchard
Zone 4b in New Hampshire



Edited 1 time(s). Last edit at 06/01/2020 06:47AM by Michael Phillips.
Re: balanced crop load
June 21, 2020 06:51PM
In the spirit of priming the community conversation pump… I’ve been working through my first season here at this 40-tree orchard. One of the hidden gifts of COVID-19 I suppose. I’ve been out almost daily thinning the trees as a break between my full-time “work from home” job plus other full-time job of having a 7-month old. So not much free time, but being in the canopy of a tree every day sure helps the balance.

I’ve decided I can’t thin them all by hand, at least not in time to help break the biennial bearing. I am still working on a plan to thin most so we can at least have improved quality of the fruit left on the tree, but that leaves my window of thinning open a bit longer. So I’m trying a little control experiment. I have three Duchess of Oldenburg’s in a nice row, and two Sweet16 next to each other, and then three Liberty in a row. My approach has been to hand-thin one of each trees, then carefully “rake batt” the second tree with a padded back end of the rake pole, and leave the third un-thinned. Like all experiments I have a hypothesis which will work best but I’d this isn’t the season for some learning, then when?

I wish there were a circular “tree hoop” net I could encircle each of the trees with to catch both the thinned apples and June drop. Especially for the Sweet16 that bear so many! Ultimately I hope to have an orchard floor that can take them and decompose them fast enough, but we’re just starting to make the transition from grass to wild to “woody duff”. Has anyone invented this type of hoop yet? Thoughts on upsides or downsides if we fashion our own?

Robyn Bipes-Timm
Wisconsin above the Mighty Mississippi
Zone 4b
Re: balanced crop load
June 22, 2020 01:27PM
Nutrient investment that supports fruit bud development really well yet in modest amounts across growing seasons is a better way of articulating this idea. There's really three phases to this:
    * Critical minerals like boron and manganese applied either side of bloom time. Site-specific additions like iron and zinc tie in as well to establish baseline amounts in available form of what's indicated by testing.
    * Recommended foliars like calcium, magnesium, manganese, and silica applied through cell division phase.
    * Summer supplementation to boost photosynthesis with continued Ca and now a tad of K too.
Years of attempting to flip the on-off switch of biennialism with thinning by hand or other means in the on-year have not brought my trees to the promised land. (Truth is I'm never-radical-enough about removing those potential fruit dollars.) That said, there's moderate set on most of my Sweet Sixteens this year after a heavy crop year in 2019. I've been getting more in-depth with foliar nutrients, using plant sap analysis and a pantry of nutrient products to supplement the fermented plant extracts brewed on the farm this time of year. The real work of "thinning the crop" is balancing meristem development in the current year, which in turn becomes next year's bloom, and then making sure that modest set of fruit buds gets full nutritional support to pull through the vagaries of winter and spring. Physical removing of weaker fruitlets after the fact -- whether by hand or with photosynthetic inhibitors like lime sulfur -- are not enough. The trees are telling us to think better than this.

And meanwhile, Robyn, thanks for taking interest and the three-variant trial you have underway. A fourth tree in the rotation where you hand thin as much again and support nutritionally (as laid out above) and this in a fungal duff ecosystem would be the eye-opener.

Lost Nation Orchard
Zone 4b in New Hampshire



Edited 1 time(s). Last edit at 06/30/2020 08:16PM by Michael Phillips.
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