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Methyl Bromide (methyl + bromide)
Selected AbstractsSELECTED ALTERNATIVES TO METHYL BROMIDE IN THE POSTHARVEST AND QUARANTINE TREATMENT OF ALMONDS AND WALNUTS: AN ECONOMIC PERSPECTIVEJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 6 2001ANTHONI F. AEGERTER Methyl bromide is a highly effective fumigant used in the postharvest and quarantine treatment of tree nuts. There will be a complete phase out in the United States of America (U.S.) of methyl bromide by 2005 according to The Montreal Protocol of 1991 with the exception of preshipment and quarantine uses as stated in the 1998 Clean Air Act. This study analyzed alternative treatment scenarios. The alternatives considered were phosphine, irradiation, and controlled atmosphere storage. Costs for each scenario were developed. Cost increases with irradiation ranged from two to fourteen times the benchmark costs for methyl bromide. Controlled atmosphere storage for both commodities had cost increases ranging from 174% to 256% over methyl bromide costs. Phosphine was used only to treat almonds. Phosphine application costs were 108% and 117% above the benchmark costs for methyl bromide. [source] Gaseous diffusion coefficients of methyl bromide and methyl iodide into air, nitrogen, and oxygenHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 6 2009Naoki Matsunaga Abstract The gaseous diffusion coefficients of methyl bromide (CH3Br) and methyl iodide (CH3I) into dry air, nitrogen, and oxygen have been measured in the temperature range 303,453 K and at atmospheric pressure via the Taylor dispersion method. Both for methyl bromide and methyl iodide, the diffusion coefficients do not vary in practice on substituting pure nitrogen or oxygen for dry air. The diffusion coefficients for methyl iodide are systematically smaller than those for methyl bromide by about 11%. For the methyl iodide-oxygen system, the effect of the thermal decomposition of methyl iodide has been observed at 453 K. The present results can be reproduced well by the functional form D = ATB, where D (cm2s,1) is the diffusion coefficient at 101 325 Pa (1 atm) and T (K) is the absolute temperature. The constants A and B are as follows: methyl bromide-(air, nitrogen, oxygen), A = 5.57 × 10,6, B = 1.76; methyl iodide-(air, nitrogen, oxygen), A = 5.26 × 10,6, B = 1.75. © 2009 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20255 [source] SELECTED ALTERNATIVES TO METHYL BROMIDE IN THE POSTHARVEST AND QUARANTINE TREATMENT OF ALMONDS AND WALNUTS: AN ECONOMIC PERSPECTIVEJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 6 2001ANTHONI F. AEGERTER Methyl bromide is a highly effective fumigant used in the postharvest and quarantine treatment of tree nuts. There will be a complete phase out in the United States of America (U.S.) of methyl bromide by 2005 according to The Montreal Protocol of 1991 with the exception of preshipment and quarantine uses as stated in the 1998 Clean Air Act. This study analyzed alternative treatment scenarios. The alternatives considered were phosphine, irradiation, and controlled atmosphere storage. Costs for each scenario were developed. Cost increases with irradiation ranged from two to fourteen times the benchmark costs for methyl bromide. Controlled atmosphere storage for both commodities had cost increases ranging from 174% to 256% over methyl bromide costs. Phosphine was used only to treat almonds. Phosphine application costs were 108% and 117% above the benchmark costs for methyl bromide. [source] Effects of reduced-rate methyl bromide applications under conventional and virtually impermeable plastic film in perennial crop field nurseriesPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 8 2010Bradley D Hanson Abstract BACKGROUND: Producers of perennial crop nursery stock in California use preplant soil fumigation to meet state phytosanitary requirements. Although methyl bromide (MB) has been phased out in many agricultural industries, it is still the preferred treatment in the perennial nursery industry and is used under Critical Use Exemptions and Quarantine/Preshipment provisions of the Montreal Protocol. The present research was conducted to evaluate reduced-rate MB applications sealed with conventional and low-permeability plastic films compared with the primary alternative material. RESULTS: Reduced rates (100,260 kg ha,1) of MB applied in combination with chloropicrin (Pic) and sealed with a low-permeability plastic film provided weed and nematode control similar to the industry standard rate of 392 kg ha,1 MB:Pic (98:2) sealed with high-density polyethylene (HDPE) film. However, the primary alternative chemical, 1,3-dichloropropene (1,3-D), tended to provide slightly lower pest control even on sites with relatively low plant parasitic nematode, soil-borne pathogen and weed pest pressure. CONCLUSION: If California regulations change to allow the use of low-permeability films in broadcast fumigant applications, the results of this research suggest that reduced rates of MB in perennial crop nurseries could serve as a bridge strategy until more technically, economically and environmentally acceptable alternatives are developed. Published 2010 by John Wiley & Sons, Ltd. [source] To what extent are soil amendments useful to control Verticillium wilt?PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 8 2009Nieves Goicoechea Abstract The genus Verticillium includes several species that attack economically important crops throughout the world. The control of Verticillium spp. becomes especially difficult when they form microsclerotia that can survive in the field soil for several years. It has been common practice to fumigate soil with chemicals such as methyl bromide and/or chloropicrin to control soil-borne fungal pathogens. Other chemicals that are used against Verticillium spp. are the antifungal antibiotic aureofungin, the fungicides benomyl, captan, carbendazim, thiram, azoxystrobin and trifloxystrobin and the plant defence activator acibenzolar- S -methyl. However, the potential risks involved in applying phytochemicals to crop plants for both the environment and human health, together with their limited efficacy for controlling Verticillium -induced diseases, support the need to find alternatives to replace their use or improve their efficacy. Soil amendment with animal or plant organic debris is a cultural practice that has long been used to control Verticillium spp. However, today the organic farming industry is becoming a significant player in the global agricultural production scene. In this review, some of the main results concerning the efficacy of several soil amendments as plant protectors against Verticillium spp. are covered, and the limitations and future perspectives of such products are discussed in terms of the control of plant diseases. Copyright © 2009 Society of Chemical Industry [source] Multivariate analysis of toxicological and environmental properties of soil nematicidesPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 1 2009Sara Sánchez-Moreno Abstract BACKGROUND: In intensive agriculture, the use of pesticides and soil fumigants is necessary to produce economically viable crops worldwide. However, this practice may involve undesirable effects on human health and the environment. In 1995, methyl bromide was restricted by the Montreal Protocol because of possible ozone depletion. The objective of this study was to compare intrinsic environmental and toxicological properties of 11 active substances with nematicidal properties, some of them recognized as methyl bromide alternatives. RESULTS: Four groups of active substances were discriminated by a series of principal component analyses (PCAs): (a) high toxicity to non-target fauna, humans and animals and medium persistence in the environment (cadusafos, ethoprophos and fenamiphos); (b) high toxicity to humans, animals and non-target fauna and high persistence (carbofuran and fosthiazate); (c) low toxicity to non-target fauna, humans and animals and low persistence (carbosulfan, benfuracarb and oxamyl); (d) low toxicity to humans, animals and non-target fauna and medium persistence in the environment (1,3-dichloropropene, chloropicrin and methyl bromide). CONCLUSION: Evaluating the multiple aspects of toxicological and environmental properties of active substances through PCA is proposed as a helpful tool for initially comparing the complex toxicological behaviour of active substances as plant protection products. Copyright © 2008 Society of Chemical Industry [source] Nematicidal activity of anion transport blockers against Meloidogyne incognita, Caenorhabditis elegans and Heterorhabditis bacteriophoraPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 6 2008Dhana Raj Boina Abstract BACKGROUND: Because methyl bromide has been phased out as a soil sterilant, new nematicides are urgently needed. Four different chemical classes of organic acids acting as anion transport (AT) blockers were tested against a free-living nematode, Caenorhabditis elegans Maupas, a plant-parasitic nematode, Meloidogyne incognita (Kofoid and White) Chitwood, and an entomopathogenic nematode, Heterorhabditis bacteriophora Poinar, in toxicity bioassays. The materials tested were DIDS (4,4,-diisothiocyanatostilbene-2,2,-disulfonic acid), 9-AC (anthracene-9-carboxylic acid), NPPB [5-nitro-2-(3-phenylpropylamino)benzoic acid] and IAA-94 (indanyloxyacetic acid). RESULTS: All the compounds showed slowly developing nematicidal activity against second-stage juveniles of M. incognita and adults of C. elegans, but not against H. bacteriophora infective-stage juveniles. The LC50 values of these compounds were < 50 mg L,1 after 48 and 72 h incubation, while at 168 h incubation the LC50 values were < 10 mg L,1 for both sensitive species. Across both species and time, the LC50 values generally differed no more than twofold among the four compounds tested in this study. In contrast, none of the compounds (200 mg L,1) caused more than control mortality to H. bacteriophora, even after 168 h of incubation. CONCLUSION: These compounds are potential leads for commercial nematicides. The insensitivity to H. bacteriophora is consistent with the natural exposure of this nematode to DST (3,5-dihydroxy-4-isopropylstilbene), a stilbene produced by its symbiotic bacterium. Based on the known activity of the compounds used in this study, it is suggested that anion transporters form the probable target sites for DIDS, 9-AC, NPPB and IAA-94 in nematodes. Copyright © 2008 Society of Chemical Industry [source] Physical, chemical and environmental properties of selected chemical alternatives for the pre-plant use of methyl bromide as soil fumigantPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 2 2006Luis O Ruzo Abstract Production and use of methyl bromide, a soil fumigant, are being restricted because of this chemical's deleterious effects on stratospheric ozone concentrations. Several products, some of which are currently used as soil fumigants, are being considered as possible replacements for methyl bromide, alone and in various combinations. Among these, 1,3-dichloropropene, methyl isothiocyanate generators such as metam-sodium, and chloropicrin are currently registered, while others such as methyl iodide and sodium azide are at different stages of the registration process. This review examines physicochemical properties, environmental fate, and metabolism of the various potential methyl bromide replacement products. Copyright © 2005 Society of Chemical Industry [source] The potential efficiency of irrigation management and propargyl bromide in controlling three soil pests: Tylenchulus semipenetrans, Fusarium oxysporum and Echinochloa crus-galliPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 8 2005Suzanne E Allaire Abstract Propargyl bromide (3-bromopropyne, 3BP) is a potential alternative for methyl bromide. Little information is available about its efficiency in controlling pests. The purpose of this paper is to estimate the 3BP dose required for killing three pests and to compare the efficiency of water management approaches to that of fumigation. The pests, Fusarium oxysporum Schlecht (fungus), Echinochloa crus-galli (L) Beauv (grass) and Tylenchulus semipenetrans Cobb (nematode) were exposed to different 3BP concentrations in a sandy loam at 30 °C in a closed system. The lethal dose for killing 90% of the population (LD90) was calculated from the total applied mass, and varied from 0.3 µg g,1 soil for the nematode, 3 µg g,1 for the grass, and 9 µg g,1 for the fungus. The concentration,time index for killing 90% of the population (CT90) was 11 µg g,1 h for the nematode, 112 µg g,1 h for the grass and 345 µg g,1 h for the fungus. 3BP seems as efficient as other fumigant alternatives in controlling these pests. Using an open system, it was shown that the volume of soil in which the pests were controlled varied for different irrigation managements. Even 96 h after fumigation (with a concentration 10 times higher than would potentially be applied in the field), more than 20% of the soil volume had not reached the fungus and grass CT90 of the non-irrigated soil. The soil underneath the furrow and the bed reached CT90 only slowly in all irrigated treatments even though techniques for increasing efficiency were used (tarping, surface sealing with water and high application rate). Copyright © 2005 Society of Chemical Industry [source] Replacing methyl bromide in annual strawberry production with glucosinolate-containing green manure crops,PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 9 2003Luca Lazzeri Abstract The use of biocidal green manure crops is an agronomic technique for amending soil with fresh organic matter containing volatile compounds active in controlling some soil-borne pests and diseases. Two new selections of the Brassicaceae family were cultivated, incorporated before planting strawberries and tested as an alternative to fumigation with methyl bromide. Two biocidal green manure crops (Brassica juncea L sel ISCI20, Eruca sativa Mill cv Nemat) containing glucosinolate,myrosinase systems, a conventional green manure (barley), untreated soil and a fumigated control were evaluated during two seasons. The effect of these soil management systems on subsequent strawberry performance was evaluated by monitoring yield and plant growth parameters. In both years, biocidal plant green manure treatments led to a fruit yield lower than with methyl bromide, but higher than with conventional green manure or untreated soil. These results confirm the good prospects for biocidal green manures, not only as an environmentally friendly alternative to methyl bromide in conventional agriculture, but also in organic agriculture as an alternative to conventional green manure crops. Copyright © 2003 Society of Chemical Industry [source] Effect of temperature, organic amendment rate and moisture content on the degradation of 1,3-dichloropropene in soil,PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 12 2001Robert S Dungan Abstract 1,3-Dichloropropene (1,3-D), which consists of two isomers, (Z)- and (E)-1,3-D, is considered to be a viable alternative to methyl bromide, but atmospheric emission of 1,3-D is often associated with deterioration of air quality. To minimize environmental impacts of 1,3-D, emission control strategies are in need of investigation. One approach to reduce 1,3-D emissions is to accelerate its degradation by incorporating organic amendments into the soil surface. In this study, we investigated the ability of four organic amendments to enhance the rate of degradation of (Z)- and (E)-1,3-D in a sandy loam soil. Degradation of (Z)- and (E)-1,3-D was well described by first-order kinetics, and rates of degradation for the two isomers were similar. Composted steer manure (SM) was the most reactive of the organic amendments tested. The half-life of both the (Z)- and (E)-isomers in unamended soil at 20,°C was 6.3 days; those in 5% SM-amended soil were 1.8 and 1.9 days, respectively. At 40,°C, the half-life of both isomers in 5% SM-amended soil was 0.5 day. Activation energy values for amended soil at 2, 5 and 10% SM were 56.5, 53.4 and 64.5,kJ,mol,1, respectively. At 20,°C, the contribution of degradation from biological mechanisms was largest in soil amended with SM, but chemical mechanisms still accounted for more than 58% of the (Z)- and (E)-1,3-D degradation. The effect of temperature and amendment rate upon degradation should be considered when describing the fate and transport of 1,3-D isomers in soil. Use of organic soil amendments appears to be a promising method to enhance fumigant degradation and reduce volatile emissions. Published in 2001 for SCI by John Wiley & Sons, Ltd [source] Characterization of a fatal methyl bromide exposure by analysis of the water coolerAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 7 2009David J. Hewitt MD Abstract Background A suspected inhalation exposure to methyl bromide (MeBr) in the packaging and shipping area of a chemical manufacturer resulted in a worker fatality and several symptomatic cases. However, air testing was negative for MeBr resulting in uncertainty regarding the potential chemical exposure. Methods of quickly confirming the exposure and magnitude were sought. Methods Head space air and water samples were obtained from the breakroom water cooler in the facility and tested for MeBr. Results Increased levels of MeBr were identified in the air and water samples from the cooler and used to calculate the MeBr concentration of air entering the cooler. The MeBr air concentration within the breakroom was estimated as 1,200,2,100,ppm depending on assumptions regarding the amount of water dispensed from the cooler both before and during the incident. Conclusions Estimated MeBr air concentrations in the breakroom were consistent with those known to be associated with reported health effects among the involved workers. The water cooler analysis represented a unique method of retrospectively verifying and quantifying exposure to MeBr. Am. J. Ind. Med. 52:579,586, 2009. © 2009 Wiley-Liss, Inc. [source] Dangerous Holes in Global Environmental Governance: The Roles of Neoliberal Discourse, Science, and California Agriculture in the Montreal ProtocolANTIPODE, Issue 1 2008Brian J. Gareau Abstract:, This paper explores how a relatively successful global environmental treaty, the Montreal Protocol on Substances that Deplete the Ozone Layer, is currently undermined by US protectionism. At the "global scale" of environmental governance, powerful nation-states like the US prolong their domination of certain economic sectors with the assistance of neoliberal discourse. Using empirical data gathered while attending Montreal Protocol meetings from 2003 to 2006, I show how US policy undermines the Montreal Protocol's mandate to phase out methyl bromide (MeBr). At the global scale of environmental governance the US uses a discourse of technical and economic infeasibility because, in the current neoliberal milieu, it cannot make a simply protectionist argument. The discourse, in other words, is protectionism by another name. While much of the literature in critical geography on neoliberalism has focused on de-regulation versus re-regulation, this paper illustrates how science, protectionism, and neoliberalism can become articulated uneasily and in sometimes unexpected ways. [source] A Versatile Synthesis of Annulated Carbazole Analogs Involving a Domino Reaction of Bromomethylindoles with Arenes/HeteroarenesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 4 2009Vasudevan Dhayalan Abstract A ZnBr2 -mediated arylation of aryl/heteroaryl methyl bromides with arenes at 80 °C led to the formation of arylated products, which underwent subsequent 1,5-sigmatropic rearrangement followed by electrocyclization and aromatization with loss of a diethylmalonate unit to afford the corresponding annulated products. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] | ||||||||||