A DOG, A KID, AND A WALNUT TREE

July 13, 2016: "A dog, a kid, and a walnut tree, the more you beat them the better they be." That's an old Appalachian saying. Let me say, right away, that I DO NOT agree with that . . . at least the first two targets. The third, the walnut, well there may be something to that.

First of all, to be fair to the people of Appalachia, they did not originate this cruel and insensitive adage. It passed to the colonies from Old England and from Europe and varied slightly in that the dog and the kid were sometimes replaced by similarly defenseless targets such as mules, horses, and women. The walnut it appears has never been substituted for anything else over time.

I'm fascinated with how agricultural adages evolved. It obviously starts with observation of results. Along the way, it may be accompanied by insightful or hokey reasoning, but in the end does science eventually back it up? In the case of the walnut tree, it does.(the dog and kid part of it was probably thrown in there by some child beating, animal abusing jerk of a forebear).

Walnut whippingWalnut whipping"Whipping walnuts" was a procedure where the trunks were beaten with long sticks and the result was often greater walnut production the next year. Walnuts were not the only trees to suffer at the hands of trunk mutilators. In the Deep South, pecan growers would take logging chains and beat their pecans trees for better pecan production. In Oregon, some holly growers would shoot their trees with bird shot to increase the next year's amount of holly berries for their Christmas greens trade. Apple and pear growers cut strips of bark off their trees in a process called "ringing" to reduce vegetative growth while increasing future fruit production.

The most commonly held reasoning of the time was that by mutilating the trunk of a tree you "scared" theBark ringingBark ringing tree into producing more fruit. Increased flowering (from which comes fruiting) was the tree's response, a last ditch effort at propagation before the tree mutilator returned. Wow, if trees went to the movies and Alfred Hitchcock was a tree, I can see a whole different, and more terrifying version of Psycho here. But trees don't go to the movies (and it's probably a good thing 'cause you'd never see anything if you sat in the back row) and they don't respond to anthropomorphic (ascribing human qualities to non-human things) reasons such as fear, thinking. or the desire to have some last minute propagation fling. There is physiology behind the responses of plants and it is the science that is behind the adage that is fascinating.

Plants, with the exception of mosses and liverworts, have a vascular system. For that matter, we have a vascular system -our arteries, veins and heart that move blood through our body. Vascular plants have xylem and phloem that move sap through their bodies. The xylem moves water and dissolved nutrients from roots to leaves and shoots. In trees (except for palms) It's located in the sapwood, the outermost and newest laid rings of wood. The phloem moves food (sugars) made by the leaves down to the live growing portions of the trees - the trunk cambium and the root tips. This phloem is located in the inner bark which lies just underneath the outer bark.

So when someone with a big stick or logging chain or shotgun comes up to a tree and whams it upside the trunk, it damages the phloem. Food can then not pass through the injured tissue and more of it remains in the top of the tree, where the new surplus is then put to use in flower buds and subsequent fruit production. The tree will attempt to regrow new tissue with phloem over the damaged area to reconnect the system. This new growth is called callus tissue. Since there are more photosynthates (food) trapped above the damage, there is more callus growth there often causing a swelling above the damage. I've seen this a lot, particularly with unintentional tree mutilation such as tree staking.

Ever plant a tree and to keep it from falling over in a high wind you drive a wooden stake or two into the Girdling due to StakingGirdling due to Stakingground and then tie the stake to the tree trunk and then walk away and forget it? Eventually that tree tie begins to girdle the trunk and constrict the phloem as it expands outward and you have the same effect as whacking it with a chain. If I had a low fat, decaf, caramel macchiato for every customer's tree I removed from careless tree staking, I'd be hanging out in Starbucks for a couple of weeks. Come to think of it, I have noticed an increased growth above my belt line over the past ten years. Maybe my belt is girdling me and it time to switch to suspenders.

Because of the science behind the adage, we can now see that beating some fruit and nut trees may indeed make them better, for fruit production, at least. And, I might further point out, that since dogs and kids do not have xylem and phloem then beating them is patently absurd, most ineffective and without scientific basis.

Observant reader that you are, you're probably wondering whether such trunk torture techniques are harmful to the tree. The answer to that is yes. Those same sugars that are trapped in the crown are not Girdling due to PartakingGirdling due to Partakinggetting to the roots. A healthy tree has a lot of stored food in its roots and may be able to stand it for a year or several, but eventually when it runs out of food the root dies. It also depends on the severity and extent of phloem damage. Is it 50%, 70%, 100% of the circumference of the phloem damaged? Some young apple trees can withstand 90% ring barking once. It also depends of tree species, vigor, age - a lot of variables and from what I've been able to garner there's not a lot of research out there on this topic.

Beware and be aware of the wanton beating of your fruit and nut trees. In the case of old non-producing trees, it may be an alternative to try before the final solution of removal.

F & P