What influences the thickness of growth rings in trees?

[Chippintuff]

I know that trees that grow faster have thicker growth rings, but there is more to it than that. Also, Osage growth rings seem to be thicker close to the stump than higher up the log.

What I am wondering is what other factors influence the thickness of growth rings, especially the late growth (summer to fall)? My guess is that water, fertility of the soil, amount of crowding and how much fruit is on the tree. I am thinking that the one thing that could be controlled with the greatest ease is the amount of fruit on the trees. If the fruit was knocked off as soon as it got big enough to see, wouldn't that cause the late season wood to grow thicker? If so, a little planning ahead and knocking the fruit off might produce better bow wood. Does anyone have experience with this?

WA

[Hrothgar]

I think you have covered the  main factors- amount of moisture, regularity of moisture, competition for sunlight, soil nutrition-all of which we can't control for a tree in the woods.  Keep in mind that its only the female tree that is producing the hedge apples, but its an interesting thought.

[Morgan]

I cut a pair of hackberry growing side by side. Pretty close to same diameter within 1/2” or so. Very different growth rings. I can’t figure why at all.

[Springbuck]

 Around here you can count the drought years by where the growth rings close down to hairlines on woods like black locust.  It's all about water, sunlight, and genes.

[osage outlaw]

There is more to it than just soil conditions.  I've cut small diameter trees with paper thin rings growing next to large diameter trees with thick rings.  I have no clue what causes it.

[Pat B]

genetics

[PatM]

Genetics first and then epigenetics.

 A tree can have its expression of genes altered by external stimuli.  There is tree in Norway of almost 10,000 years of age which has been a stunted shrub and a tall tree depending on the changing environment over the millennia.

[M2A]

I am thinking that the one thing that could be controlled with the greatest ease is the amount of fruit on the trees. If the fruit was knocked off as soon as it got big enough to see, wouldn't that cause the late season wood to grow thicker? If so, a little planning ahead and knocking the fruit off might produce better bow wood. Does anyone have experience with this?

WA

Interesting question, Made me think. I have more experience with growing trees than making bows.
Fruit thinning has been used in fruit production for years to achieve several outcomes. One being More vegetative growth in a particular growing season. I know from experience that a light fruit load will produce more growth in tree fruits. Now...will this produce better bow wood? I'm not too sure, it could be a lighter SG than it would be otherwise. Sooner you thin the more chance for more growth. Trees do not make up for lost time, if they miss the opportunity to grow its gone. I spent too many days hand thinning fruit years ago, not my favorite thing to do    

Lots of factors, all mentioned above contribute. However I will say...identical trees side by side, same genetics they still grow different(faster/slower), but similar go figure lol.

Now, I just wonder if I started sneaking in osage whips in blank spots in the orchard, how long would it be till someone caught on   

Hope this helps, Mike                   

[PatM]

Marc mentioned cutting an Elm that was forked at ground level and one half was  great and the other half sub-par.