Its pretty easy for both sides to lose perspective over this herbicide issue. Its also common in these debates to find alot of half-truths and value statements that are presented as fact. One thread in the discussion is that glyphosate kills "non-target" species. Someone else chimed in that this particular non-target species is a legume that is a major player in the N cycle. Then, someone else reported that, in Humbold Co, CA in 1997, 11,348 acres were treated with 8731 gallons of Garlon and atrazine and that 6168 acres were treated with 1010 pounds of Oust. To someone who is uninformed and predisposed to extreme environmentalism, it would seem that the nutrient cycling of the Canadian Taiga was being poisoned, and that Northern California was being converted to a toxic waste dump. Since glyphosate blocks the synthesis of amino acids (phenylalnine, tryptophan and tryosine, in particular), it should not be too supprising that "non-target" species are also affected. It is also not surprising that glyphosate is non-toxic to animals at label concentrations because animals do not posess the shikimic acid pathway where these amino acids are synthesized. Whats more, the so-called legume under discussion is, in fact, neither a legume nor an N-fixer. In California, the amounts of chemicals reportedly used ammount to about 3 quarts per acre of either Garlon or atrazine and 2.6 oz (weight) per acre of Oust. These applicaiton rates are well within label specifications. Lets not forget that we must talk about these things in terms of toxic concentrations, and not in terms of toxic molecules. On the other hand, the chemicals that we are referring to are not TOTALY benign. They do, after all, exist for the sole purpose of killing stuff (but only insofar as it will benefit other stuff). Ironically, there are many many things that we use in every day life that are not *intended* to kill anything at all, and yet are far more potent killers than most common herbicides. As we all know, these "other things" do have appropriate, safe uses. The same is true for most common herbicides. They must be used with strict adherence to the label, with the appropriate equipment, and by properly trained personnel. If they are used carefully and with forethought, they are a safe, effective tool of agriculture and forestry. Too often, I fear, herbicide application may suffer from the "that's the way we've always done it" syndrome. Abuses do occur, and mistakes happen. Sometimes, mistakes can be very costly in terms of both capital investment and the environment. Extreme positions on either side do very little to solve/correct/avoid such mistakes, or to resolve value dichotomies between different interest groups. To refer to forest managers who value timber production more than blueberries as "silly", to refer to herbicide use as "introducing poison into the ecosystem", and to refer to industrial forestry as "wholesale destruction" contributes little to the discussion. Dr. Mark E. Kubiske Phone: 601-325-3550 Department of Forestry Fax: 601-325-8726 Box 9681 Email: mkubiske@cfr.msstate.edu Mississippi State University Mississippi State, MS 39762-9681 USA ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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