Hey Rowan,

I am an Apple grower and have little experience with wood testing on our farm personally. The experience I have is second hand from a consultants experience.

My understanding is:

The older the wood the less nutrients you will have access to.

1 year old growth is the the most nutrient dense and thus removing all new growth may be counterproductive.

It is understood that by dormant pruning we are limiting new root growth which limits the availability of nutrient access.

In regards to the differences in wood tests compared to sap testing I imagine this has to do with mobility of nutrients and how micronutrients are stored in certain species.

It would be great to learn more about this topic and understand how different parts of perennial plants store nutrients. We may gain a better understanding of how to unlock stored nutrition(maybe we need to examine endophytes?) and recognize how sap tests relate to the entire sphere of testing.

This article talks about peach tree pruning and macro nutrient removal: https://www.growingproduce.com/fruits/stone-fruit/do-you-know-how-good-your-fertilization-program-is/

Kyle Rasch

Farm Manager-Third Leaf Farm