July 2005

Pesticide Potpourri

  • wpdoc19.gifResearchers at Yale have identified a gene that regulates the major immune response in plants, programmed cell death (PCD). To protect themselves from viruses, plants create a zone of dead cells around an infection site that prevents the infection from spreading. They identified and silenced a "pro-survival" gene, BECLIN-1, that is important in the PCD response. When BECLIN-1 is active, infection is localized to a small number of cells that later die and form discrete brown lesions on the leaves. When the gene is inactivated, the plant can no longer regulate PCD, leading to cell death throughout the leaf and plant. The process of PCD has been described in virtually all cell types, both plant and animal. It is an important aspect of many biological processes including immune system function, embryonic development and elimination of defective cells. Failure of PCD can result in devastating diseases such as cancer, Alzheimer's and AIDS. (Yale News Release, 6/10/05).
  • wpdoc20.gifIn India, B.t. cotton has been in commercial cultivation since 2002. There are “official” seeds and “unofficial” seeds (patent infringement) available in the market. Monsanto and its Indian affiliate Mahyco, claim that the “unofficial” hybrids are not as good as the “official” plants, and activist organizations have used this as a claim that the technology itself does not provide any advantages. A survey of 622 farmers (306 - “official”, 169 - “unofficial”, and 151 - conventional non-B.t.) revealed that gross margin was significantly higher for the “official” seeds, followed by “unofficial” seeds, followed by conventional seeds, even though seed price is less with bootlegged seed and even lower for conventional seed. (AgBioForum, 6/13/05).
  • wpdoc21.gifNeonicotinoids, such as imidacloprid, are nicotinic acetylcholine receptor (nAChR) agonists with potent insecticidal activity. Since its introduction in the early 1990s, imidacloprid has become one of the most extensively used insecticides for both crop protection and animal health applications. As with other classes of insecticides, resistance to neonicotinoids is a significant threat and has been identified in several pest species, including the brown planthopper, a major rice pest in many parts of Asia. In a recent study, whole-body membranes prepared from imidacloprid-susceptible and imidacloprid-resistant strains of brown planthopper reveal a much higher level of imidacloprid-specific binding in the susceptible strain than in the resistant strain. A single point mutation at a conserved position in two nAChR subunits is responsible for this reduced binding. The study provides direct evidence for the occurrence of target-site resistance to a neonicotinoid insecticide. (PNAS, 6/14/05).
  • wpdoc22.gifAn outbreak of poisonous caterpillars in Germany led to school and kindergarten closures in June. A spokesman for the town of Dreieich was cited as saying that contact with the stiff-haired spines of oak processionary caterpillars, which have multiplied by the thousands in trees in the central state of Hesse, can lead to skin rashes and asthma attacks. (Agence France Presse, 6/14/05).
  • wpdoc23.gifIn 2007, Indycars will be running on 100 percent ethanol. That's ethyl alcohol - white lightning before it's denatured to make it undrinkable. The origin of the decision to switch Indy Racing League fuel to ethanol was launched in Richmond, VA at a race two years ago. League officials, representatives of the Renewable Fuels Association and race driver Paul Dana "stood by that pit wall and dreamed about the future," said Kenneth Unger, the IRL's senior vice president for business affairs. The league has not changed fuels since the 1970s when it changed to methanol. The switch to ethanol started with the league's commitment to U.S. energy security (read: independence) and to using a fuel that would reduce racing's impact on the environment. (Richmond Time-Dispatch, 6/25/05).
  • While the concept of foliar fertilization is attractive, the research to support the practice is extremely inconsistent and yield benefits associated with application of various foliar formulations are tenuous at best. An Iowa study designed to measure foliar fertilizer (N,P,K) efficacy in soybean production revealed that only about 25 percent of the 48 plots demonstrated a yield increase (applications applied at V5). For those that did show an increase in yield, the average was only one bu/acre. (C.O.R.N. Newsletter, OSU, 6/22/05).
  • wpdoc24.gifSouthwest Missouri State University is co-hosting the International Grape Genome Symposium in July, and some of the faculty from SMSU are investigating what keeps some types of grapes healthy while others fall prey to fungi, viruses and parasites. Varieties of grapes such as Bordeaux, merlot, pinot, champagne and cabernet come from the grape species Vitis vinifera. Those types of grapes are widely grown in Europe but don't do well in hot, humid climates such as that found in the southern U.S.A. Here, they are felled by powdery mildew, black rot and downy mildew. But grapes that originated here are nearly impervious to the fungi, and for that, the world's wine industry owes its literal roots to American grapes. In the 1860s, European plant collectors unwittingly transported plant pests, such as powdery mildew and the root-feeding phylloxera along with grape vines, and the pests spread rapidly through the vineyards of Europe, which had never seen ravaging aphids and fungi. Phylloxera, which has since spread around the world, nearly decimated grapes in Europe. But a shipment of roots from Hermann, MO, turned the tide. Native grapes had evolved in the presence of the aphid and are resistant to it. French winemakers grafted their grape vines to Missouri root stock and rescued the crop from the insect's ravages. Now, almost all grape vines are grafted to American roots. (St. Louis Post-Dispatch, 7/12/05).
  • Some of you may remember the story of Homan McFarling (Chemically Speaking, February 2005), who vowed to plant saved seed, just as his daddy had done. In front of the Supreme Court, he was unsuccessful in arguing that Monsanto is violating federal antitrust law by barring farmers from saving harvested seeds for use the following year. The justices made no comment in rejecting McFarling's appeal, after a federal appeals court last year ruled that the ban on "second generation" planting was within Monsanto's rights as the patent owner. (Bloomberg News, 6/28/05).

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