Friday, January 29, 2016

The cull list

There are two parts to breeding livestock or any other "farm" enterprise.  One is the choice of parents.  That is the fun part.  The other part involves "culling" and is often neglected because it is not as much fun.

Some types of purebred livestock enterprises involve saving a large percentage of the females as replacement dams.   Dairy cows are an example of this type of enterprise.  Heavy milk production limits breed-back, they have only one calf at a time and they do not have a very long production lifespan.  Beef producers will typically keep about 1/3 of their heifer calves because a typical beef cow will only produce six or seven calves in her life time.  That still limits the amount of selection pressure a producer can exert on his herd.

Plants, on the other hand, produce hundreds-to-millions more progeny than "replacement".  That allows the grower to exert much higher selection pressure.  A serious tree grower does not need much of a reason to cull a tree, and the sooner it is done the sooner the neighboring trees are released from the competition.

Three Quercus robur, European Oak, the oak of Robin Hood, Sherwood Forest and all of that.  The one on the left will be culled because the other two trees have better geometry.
Trees that have branches that are perpendicular to the trunk are less subject to ice damage and produce better trunks for lumber.  Narrow crotch angles tend to develop regions of ingrown bark.  That bark interrupts the grain and weakens the branch.  It also becomes an area where cankers as disease  organisms like Nectria thrive.  Finally, branches that are perpendicular to the truck develop less size than upwardly oriented branches.  Smaller branches means smaller knots in the lumber.

This tree is not a dogwood, it is a Red Maple.  It never developed interesting fall color.  I will replace it with Q. lyrata hybrids because I like Oak trees.
These Norway Spruce will be thinned out.  I noticed that many of the spruce trees in Eaton Rapids are in decline, most likely due to Phomopsis.  Engelmann and Blue Spruce are most vulnerable but it is hammering the Norway Spruce as well.  There is little the owner can do except to try and keep the tree(s) in a robust state of good health and to maximize airflow.  Reducing crowding accomplishes both.
You can see that I get a lot of help from the dogs.  Marking trees is their specialty!!!  This is a chestnut tree that winterkills during severe winters.
There are two kinds of trees:  Trees that pay their rent and put money in your pocket and trees that don't. 

Life is better when you have more of the first kind of tree (or cows or sheep or hogs....) and none of the second kind.


  1. Those roburs have better looking form than most I see. I think robur suffers from poor genetics here, especially from nursery cultivars.

    1. I suspect that the nursery robur oaks come from a genepool that has been strongly selected for "fastigiate" form.

      I think it was Oscar Wilde who wrote, "Fashion is a form of ugly it must be changed every 6 months." Unfortunately, the damage done by "fashion" lingers on much longer than six months in the tree trade.

  2. Hadn't thought through it from the perspective you had in this post, but it makes sense. In the southwest/midwest/west, you wanted a line of spruces or similar as a windbreak for your house and barns. The closer together the better...


Readers who are willing to comment make this a better blog. Civil dialog is a valuable thing.