How Do You Thin Your Apples (and Why)? (5 replies)

At the recent Berkshire Roundtable (affectionately known as Stump Sprouts) we had a vigorous discussion about apple thinning. There was discussion of seasonal objectives, philosophies, sprays, and economics. This lead to a what I hope will be a good discussion here about about how "you" - the apple grower - approach thinning and why. One of the principle objectives I had was to create an exhaustive list of any material you may have used or thought about using to thin blossoms or fruit. Another was to establish the importance of economics of thinning your orchard. Lastly was to get a broad understanding of your holistic philosophy towards thinning.

Feel free to chime in and I will create a summary of the responses as we go along.
I'll start:

Materials
lime sulfur
fish Oil
bicarbonate
salt
Horn Silica (BD501)
Regalia
Acidic compounds (e.g., vinegar, caprylic acid, etc.)
ProTone (ABA)
Wuxal amino plant (biostimulant) - not organic
Ammonium Thiosulfate (ATS) - not organic
**these last two are interesting in that though not organic, there are other organic biostimulants and fertilizers that could be be tested in research.


Like all HON threads, this is intended to be an interactive conversation. The more we need to know about thinning, the less we actually know since research has been mostly focused on west coast conditions and dessert varieties. It also begs the question about how we can approach thinning; what tools do we have available?

Tools/Resources
Carbohydrate Modeling
Pollen Tube Growth Model
Ploidy
Biennialism
Orchard design and varietal diversity
Fertility Practices
Production History
Fruit Quality Objectivess
Climate and Weather history
Cultural Practices (pruning, hand thinning, mechanical thinning, etc.)