Also, should I use the concentrated weed killer, or use the regular diluted one? I currently use the Round-up Brsh killer, "ready to use". I do not know yet how effective it is.

"Not only is a copper nail not only not going to kill the tree, but it is a primary components of many fungicides."

Inconclusive, irrelevant and unscientific for several reasons.

The applications are entirely different. They have not presented any evidence that the copper present in fungicides, which are applied to the outside of the plants even migrates in to the plant, nor have they established the quantities of copper and how they relate to each other. Toxicology is as much about quantities and their applications as it is the material in question. Also, I fail to see why they took fungicides as their evidence. Surely the fact that copper is present in both soil and plants, and that plants purposefully asorb it and use it for biological processes is more revelevant and compelling to the issue?

However, their comparison is particuarly illogical as the copper in fungicides is part of a different compound to the copper in nails. The importance of different compounds is hard to describe without an example. Hydrogen, carbon and nitrogen are a good example. Collectively they form some 31% of the human body's mass, and they're exceptionally important materials without which we could not exist. However, they may form a number of different compounds, one of which is hydrogen cyanide, a very potent toxin that can be fatal in tiny doses. For similar reasons the copper was never the issue, but rather the form it takes.

They have failed to convince me that the copper in fungicides have any relation to the copper in nails, shown no evidence that copper in fungicides even passes through the plant's surface, and they haven't shown any comparisons between the dosage. It may be that the copper in one nail could make several thousand gallons of fungicide, I simply don't know and get the impression they haven't any idea either.

It may well turn out that I'm wrong and they're right about the main issue, if copper nails kill plants, but I would like to base my opinion on more compelling evidence than this.

Now the problem is the strong root system of the pear spreading everywhere under the ground and poping up all over with small new twigs and leaves on the earth surface. I cut the twigs with a bush cutter once a while. But they will become more, thick and stronger. Will they continue to grow, causing nearby concrete damage and messing
up my flower bed and grass? How to kill those twigs and roots, without damaging the surrounding bushes, trees and grass?

Any advice is helpful. Thanks a lot.

Yangming Cao,
Fresno Ca.

As I said, the stump of the pear tree was removed. I had to deal with the strong rooting system producing twigs on the surrounding ground everywhere. The more I cut, the worse the new twigs. The chemical I used was Roundup concentrate plus. The detail is "Kill the roots guaranteed. Roundup weed & grass killer. Concentrate plus. Net 32 fluid oz. made by Mansanto Co, Missouri, 2009". I bought this from Home Depot or Lowes or OSH, (don�t remember detail, probably Home Depot). The cost is about 10-30 US dollars (don�t remember detail). Again it should be Concentrate plus. Also need to buy a pair of gloves that are resistant to chemicals (I bought a pair of black rubber gloves long enough up to my upper forearms). The face mask is optional if wind is not strong. Also needs a clean rag or sponge (I used a small piece of cloth rag). Also needs a porcelain bowl.

Weather and timing: midday, like noon when sun is shining, is the best and when the twig are actively growing. The twig foliage should be dry without being watered or irrigated, (otherwise the chemical is diluted by water). The height of the twigs is best at 1 � 2 feet. Make sure not to spill any chemical onto the vegetable or other surrounding useful plants. If necessary, may need to separate by a cupboard. Chemical is very strong. Protect yourself. From my experience, the killing will be successful, but don�t injure yourselves.

Ready?

Now wear appropriate garment, mask and gloves. I pour the Roundup chemical into a bowl (to facilitate the handling). Wet / soak the rag in the bowel with chemical. Then rub the rag against the leaves (both sides of leaves) and twigs (all around the twigs) until they are totally wet, from the leaves all the way to ground (don�t let rag touch the earth, because the chemical is immediately inactivated by soil). Make sure do this to all the twigs. In a few hours, you will see the change. Usually by 2 weeks, all leaves and twigs die. If there is residual living twigs or leaves, may apply more chemical in 1 -2 weeks to those surviving twigs. And may apply more even some time later until they are totally die, if needed. Even with that, sometimes you may still see one to two twigs coming up the next spring. Use the chemical again. For some superficial roots, you may just dig it out as much as you can. The principle of the chemical is: the chemical is absorbed by the leaves and twigs, then transported by the stems / twigs to the root to kill the root. So for those green twigs, don�t cut but use the chemical first. Then later when they are dead, may dig it out if necessary, but many times not necessary to dig.

I applied chemical once, then add a bit one week later, then 4 weeks later for the residuals. This spring I saw only one twig and I physically removed it. No more until now. All the underground roots will die out due to the chemicals and due to lack of sun energy (because no leaves now to take in sunshine).

It is worth trying above. And post your experience later for other readers� benefit.

Yangming Cao

Yangming Cao