(Beyond Pesticides, January 25, 2012) Apple growers in Michigan are seeking a Section 18 emergency exemption from the U.S. Environmental Protection Agency (EPA) for an unregistered pesticide to curb fire blight on 10,000 acres of apples trees that are susceptible to a deadly disease. Even though Section 18 exemptions from federal pesticide law are only to be used in ‚Äėemergency conditions,‚Äô this request has been petitioned and granted over the past three years, leading to questions on the of the ‚Äúemergency‚ÄĚ that triggered the section 18 exemption request.
In December 2011, the Michigan Department of Agriculture (MDA) asked EPA to grant the use of the antibiotic, kasugamycin, to control streptomycin-resistant strains of Erwinia amylovora, the causal pathogen of fire blight, maintaining that there are no available chemical alternatives and effective control practices. The agency has requested comments until February 6, 2012 at www.regulations.gov, docket number EPA‚ÄďHQ‚ÄďOPP‚Äď2011‚Äď1016. Kasugamycin is not registered for use in the U.S. under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), but has import tolerances for residues on food imported. Fire blight has been on the increase in Michigan orchards and other states for the past few springs due to resistance the disease has to current treatments. The request entails no more than three applications of the pesticide, on no more than 10,000 acres between April 1 and May 31, 2012. The maximum amount sprayed will be approximately 30,000 gallons. MDA estimates that total losses to fire blight would be close to 90 million for apple growers in the state. According to the letter, MDA states that ‚ÄúIn order to stay competitive in the current marketplace, Michigan growers much continue to plant today‚Äôs popular varieties, most of which are highly susceptible to fire blight disease.‚ÄĚ
Under a controversial provision in federal pesticide law, known as a Section 18 exemption in FIFRA, EPA can grant temporary approval for an unregistered pesticide or an unregistered use of a registered pesticide if it determines that ‚Äúemergency conditions exist which require such exemption.‚ÄĚ The Section 18 emergency exemption loophole has been used in the past to skirt pesticide regulations meant to ensure health and safety and has resulted in the widespread application of unreviewed, and often unnecessary hazardous substances. To grant a Section 18 exemption EPA must perform a multi-disciplinary evaluation of the request including an assessment of the validity of the emergency claim and economic loss, as well as human and environmental health assessments. However, these assessments have been criticized for their inadequacies. Section 18 exemptions have been granted every spring since 2009 for kasugamycin on apples in Michigan, challenging the concept that this is an urgent, non-routine situation as ‚Äėemergency‚Äô is defined under section 18. Reoccurring problems like the fire blight in Michigan should be the wakeup call for farmers and EPA to reevaluate and implement alternative biological and cultural management practices for the long-term prevention of diseases and end the reliance on the ‚Äúchemical fix‚ÄĚ that will exacerbate the problem when pest resistance to the chemical inevitably occurs.
Kasugamycin is a low-use-rate wide-spectrum aminoglycoside antibiotic fungicide produced from Streptomyces kasugaensis that was originally developed for control of rice blast and has been granted a tolerance for its use on imported peppers and tomatoes. According to EPA, kasugamycin exhibits low acute toxicity. In chronic animal studies, reproductive toxicity was observed and included decreased fertility and fecundity in males and females. Testicular effects were also noted. Kasugamycin may also impact the kidneys. Since kasugamycin is currently used only on imported fruiting vegetable commodities, the EPA has not officially conducted an environmental assessment for this chemical. Although kasugamycin is not anticipated to be useful as an antibiotic in human or veterinary medicine, the import of its differential impacts on soil dwelling microorganisms has yet to be assessed.
Over the past few years, a trend toward greater dependence on antibiotics has been observed; however, the use of antibiotics as a ‚Äúquick fix‚ÄĚ is not sustainable since it inevitably leads to resistance. Antibiotic management poses a challenge to apple and other fruit producers. Indeed, researchers have found that some bacteria in apple orchards are resistant to kasugamycin, and kasugamycin-resistant strains could be selected through a process of exposure to increasing doses of the antibiotic. Due to the pervasive problem that fire blight has become, a systematic approach to fire blight prevention should be implemented, including resistant varieties, site selection, careful fertilization, adequate spacing of trees, and proper pruning practices.
There are now additional products available for use against fire blight, including several new biological controls. Effective organic systems can encourage and enhance preventive techniques with cultural and biological controls that include choosing varieties not susceptible to diseases. Apples that have only been introduced and become popular in the last ten years -Gala, Fuji, Granny Smith, McIntosh- are very susceptible to bacterial disease, making them increasingly chemical-intensive. Varieties that are now less well-known ‚ÄďJonathan, Gold Rush, Empire, Prima, RedFree, Golden Delicious- are more resistant to fire blight, but are not widely available in the market. Beyond Pesticides recommends educating conusumers to create a demand for these varieties by purchasing them when available. This can help shift the market away from chemical dependence and encourage farmers to grow more resistant varieties. For more information on resistant varieties and organic cultivation, read our article ‚ÄúAntibiotics in Fruit Production.‚ÄĚ
Submit your comments at www.regulations.gov, identified by docket identification (ID) number EPA-HQ-OPP-2011-1016. Comment period ends February 6, 2012.