Boron and its effect on wood quality
We have found that the trees which were treated with Boron in late 70's and early 80's, and now are being felled, are showing much better sawn timber properties than trees which were not treated.
One of the qualities which are showing up is the extra strength of the timber. Up until now we have been only guessing at the reason. Now we may have a scientific reason for the improved wood qualities.
The following is an article obtained from an overseas journal:-
Crops Rich in Pectin Demand More Boron
Some interesting information about Boron requirements in crops came across our desk recently that may be of interest to some of you. The paragraphs below are from Boron in Agriculture 1996 Vol. 16 No 2 p1
Why do most monocots have low boron requirements?
Why can plants not mobilize boron from old leaves?
Why are cell walls impaired, and tissue often brittle, in Boron deficient plants?
Answers to questions such as these may all be related to the irreversible binding of Boron with Pectin in plant cell walls.
Brown and Hu at the University of California, Davis have extended their studies on Boron physiology by relating the variability of Boron requirements amongst 14 crop species with their cell wall pectin concentration. Their results on asparagus, barley, broccoli, carrot, cauliflower, collard, cucumber, maize, onion, pea, turnip, radish, tomato and wheat are reported in the journal of Experimental Botany 1996, 47, 295, 227, 232.
Primary cell walls of graminoceios monocots contain very little pectin and the species have low boron requirements. In contrast the primary cell walls of dicots contain relatively large amounts of pectin and have high boron requirements.
Onion and asparagus, two non-graminaceous monocots, are pectin rich and have high boron requirements similar to those of - if not higher than- some of the dicots.
It is very likely that the formation of insoluble boron complexes in cell walls of plants is responsible for the immobilization of boron within tissue.
There is thus little doubt that crop species with larger amounts of pectin in their cell walls have higher tissue boron requirements.
These results can be explained in two ways. Firstly, boron may be required for the proper conformation of pectin in the cell walls, secondly, species that are rich in pectin can complex large amounts of boron- there by reducing its availability for other essential roles. Soluble boron would only be present in a potentially available form when all the complexing sites in the pectin have been satisfied.
The ability of pectin rich plants, to immobilize excess boron, may be an important factor in conferring tolerance to boron toxicity.