Bromide Fumigation Research Articles

BREAKING THE BONDAGE TO METHYL BROMIDE IN AGRICULTURE - UNIDO EXPERIENCE

For decades, methyl bromide was used as the fumigant of choice to rid the soil of noxious pests, diseases and weeds in the pre-plat stage, particularly in intensive agriculture around the world. Breaking the chains of the methyl bromide bondage by 2015 in developing countries – as set by the Montreal Protocol on the Substances Depleting Ozone Layer – has been a great challenge, but at the same has created an opportunity to promote a variety of non-chemical alternatives. By initiating the transition towards sustainable technologies, United Nations Industrial Development Organization (UNIDO) – as one of the implementing agencies of the Protocol – has been instrumental in phasing-out methyl bromide in developing countries. In partnership with local governments and institutions, UNIDO has brought the benefits of environmentally friendly alternatives to growers in various sectors around the world. Through the successful adoption of novel technologies such as vegetable grafting in Mexico, bio-control agents in Honduras, soilless systems in Turkey, biofumigation + solarization in Ecuadorean flowers or compost technology in Morocco, these growers have developed successful disease and pest management programs that not only are not reliant on methyl bromide or other soil fumigants, and which are proving to be equally efficient and sustainable in the long term. Such programs are further giving market headway to various agricultural sectors by making them more competitive in international markets, which are increasingly requiring products grown within environment-friendly standards.

Weed Community Composition in Tree Fruit Nurseries Treated with Methyl Bromide and Alternative Fumigants

Many agricultural cropping systems have relied on methyl bromide (MeBr) for pest control, including weeds, for decades. Alternative fumigants are being sought worldwide because MeBr has been identified as an ozone-layer depleting substance. Weed communities respond dynamically to alterations in management systems. Thus, transition from MeBr to alternative fumigants may cause shifts in weed communities. This hypothesis was tested in four commercial fruit nurseries in California, USA. Treatments included nonfumigated control, MeBr (98%), iodomethane (50%) + chloropicrin (50%), 1,3-dichloropropene (1,3-D), 1,3-D (61%) + chloropicrin (35%), and 1,3-D (62%) + chloropicrin (35%) applied subsurface. All the fumigants reduced the population of common major weed species and had similar species composition as MeBr. None of the fumigants, including MeBr, controlled species such as Medicago polymorpha, Lotus purshianus, Malva parviflora, Conyza sp., Senecio vulgaris, and Sonchus oleraceus. This study suggested that, fruit nurseries transitioning from MeBr to alternatives may not see an immediate shift in weed communities. However, Additional weed control measures will be required to manage weed species of the Asteraceae, Fabaceae, and Malvaceae family that are not controlled by either MeBr or the alternate fumigants.

Container Fumigation as a Quarantine Treatment for <I>Anoplophora glabripennis</I> (Coleoptera: Cerambycidae) in Regulated Wood Packing Material

Anoplophora glabripennis Motschulsky, an Asian cerambicid beetle, was first found in the United States in 1996 and was likely introduced into the United States through infested wood packing materials and dunnage. Methyl bromide (MeBr) fumigation is an internationally accepted treatment for such wood-boring beetles, but the use of MeBr is scheduled for reduction or elimination as alternatives become available. The use of MeBr can be reduced by more efficient and technically sound fumigation techniques, including good circulation and proper loading. Concentration x time products (CxT) reported for A. glabripennis in solid wood timbers were used to test estimated doses in container fumigations conducted in Tianjin and Shanghai, China, during years 2002-2003. We found that CxT products observed were generally adequate and would support reduced doses of MeBr at temperatures intermediate (10.0 and 15.6 degrees C) to the Animal and Plant Health Inspection Service schedule of 80 g and 48 g/m3 at > or =4.4 and > or = 21.1degrees C, respectively. The use of fans is recommended, and loading of the containers should never reach 100% to allow for better circulation and desorption. Proper use of fans will allow for better aeration and increase safety to inspectors and consignees of containerized fumigated commodities.

Properties and metabolic diversity of microbial communities in soils treated with steam sterilization compared with methyl bromide and chloropicrin fumigations

The effects of steam sterilization (SS) on soil microbial properties including metabolic diversity of the microbial communities were examined in a greenhouse compared with those of two fumigants, methyl bromide (MB) and chloropicrin (CP). The numbers of fungi decreased in all the treatments. Nitrifiers, both ammonium-oxidizing bacteria and nitrite-oxidizing bacteria, were severely affected by the SS and CP treatments, resulting in their virtual disappearance. The decrease in the levels of microbial biomass C and N after the treatments suggested that the SS and CP treatments eradicated the microorganisms more effectively than the MB treatment and that the influence of the former persisted until the end of the experiment, 4 months after the treatments. Accumulation of NH4-N was observed after the SS and CP treatments mainly due to the partial decomposition of the dead microorganisms and the marked decrease in the number of ammonium-oxidizing bacteria. The richness and average well color development (AWCD) values in the microbial communities after the SS treatment were evaluated by the carbon substrate utilization method using Biolog ECO MicroPlates. The values decreased markedly immediately after the treatment but showed a rapid recovery, while those after the CP treatment continued to decrease until the transplanting of tomato seedlings. The effect of the MB treatment on the soil microbial communities was less pronounced. The growth of the tomato plants was promoted by the SS and CP treatments due to the increase in the N supply at the initial stage of tomato growth.

Open‐path FTIR air monitoring of phosphine around large fumigated structures

AbstractStorage structures (silos, warehouses, and similar structures) are routinely fumigated for disinfestation of pests. This process includes sealing the structure, adding a fumigant (phosphine, methyl bromide, and other fumigants), maintaining a certain concentration of the fumigant, and aerating the structure after all fumigant has been removed or has dissipated. Phosphine concentrations in the air surrounding large fumigated structures at a tobacco storage facility were measured using an open‐path Fourier transform infrared (FTIR) spectrometer system. These measurements provided more comprehensive data than could be obtained with multiple single‐point detection devices. Specifically, this novel application of open‐path FTIR was investigated to more completely characterize phosphine concentrations over long path lengths using a single FTIR. Phosphine levels were below the detection limit [<0.07 parts per million (ppm)] approximately 20 meters (m) east of a warehouse. Phosphine was detected at approximately 4 ppm inside a warehouse at the end of fumigation and just prior to aeration. Levels of phosphine directly in front of the doors of another fumigated warehouse, immediately after aeration, ranged from <0.07 to 8.3 ppm. Six different sampling paths were also used to investigate the levels of phosphine in various areas of the facility. Average phosphine levels in air around sealed warehouses under active fumigation were found to be the below detection limit. © 2001 John Wiley & Sons, Inc. Field Analyt Chem Technol 5: 116–120, 2001

Effect of methyl bromide and dazomet on germination ofTilletia indicateliospores in field soil

Abstract Methyl bromide and dazomet fumigants were applied to soil at the rate of 454 kg/ha a.i. to determine their effects on viability of Tilletia indica teliospores. At 5 and 10 cm depth, the teliospore germination was 0 and 0.02%, and 2.41 and 0.60%, in plots treated with methyl bromide and dazomet, respectively. In the untreated control plot, germination was 9.91 and 7.16%.

Methyl Bromide Fumigation for Control of Oriental Fruit Fly (Diopters: Tephritidae) in California Stone Fruits1

Methyl bromide (MB) fumigations at ambient (21 ± 1) and higher (≥30) temperatures were developed for control of oriental fruit fly (OFF), Daces dorsals Handel, in California stone fruits. The fumigation schedules for OFF dis infestation with probity 9 quarantine security at the 95% CL were 48 g/m3 MB for 2.0 h at ambient temperature for nectarines, peaches, and plums; 32 g/m3 MB for 1.5 h or 48 g/m3 MB for 1.0 h at 30 (or above) for nectarines and peaches; and 32 g/m3 MB for 2.0 h or 48 g/m3 MB for 1.5 h at 30°C (or above) for plums. All fumigations were at normal atmospheric pressure.

Ethylene Dibromide Fumigation of California-grown Citrus: Effect of Dosage, Temperature, and Load Factor on Gas Concentration, Sorption, and Residues

Ethylene di bromide (EDB) fumigation of commercially packed lemons, navel oranges, and ‘Valencia’ oranges showed that lemons and navel oranges were equally sorptive of EDB; ‘Valencia’ oranges were less sorptive. Increased dosages produced higher gas concentrations during the exposure time (CT products), but had no significant effect on sorption. Effects of temperature (10, 20, or 30°C) on CT products and sorption were not significant. Increased load factors produced higher percentage sorption and lower CT products. Levels of residual EDB in citrus fruits immediately after fumigation were proportional to CT product exposures. Rates of desorption of EDB from most to least rapid from fumigated citrus stored at 5°C were lemons greater than navel oranges greater than ‘Valencia’ oranges. Levels of residual EDB in fumigated citrus fruits stored at 5°C would reach ≤0.25ppm (250 ppb) in 21 ± 2.8 days for lemons, 31 ± 3.5 days for navel oranges, and 41 ± 5.7 days for ‘Valencia’ oranges.

Helicella Snails Infesting Rosemary Seeds: Methyl Bromide and Other Fumigants for Quarantine Control12

Small-scale laboratory tests in 1971-72 indicated control of two species of juvenile Helicella infesting seeds of rosemary, Rosmarinus officinalis L., in fumigations at reduced pressure near 100 mm Hg with methyl bromide (MeBr) 48 mg per liter for three hours. Preliminary germination tests of tolerance shortly after fumigation or following storage at 5.6–7.2°C for 12-16 months indicated little or no effect from MeBr 128 mg per liter for 16 hours at reduced pressure or 240 mg for 24 hours at normal atmospheric pressure (NAP). Tolerance of seed also appeared acceptable following NAP fumigation with sulfuryl fluoride 48 mg per liter for 72 hours or an ethylene oxide-carbon dioxide 10:90 mixture 416 mg per liter for 48 hours.

Methyl Bromide, Sulfuryl Fluoride, and Other Fumigants Against Quarantinable Cochlicella and Theba Snails2

In tests conducted during 1958–63, estivated snails proved very resistant to fumigation. Cochlicella barbara (L.) and related species required 8 lb methyl bromide/ 1000 ft3 for 72 hr at 55°F or above in tight chambers or under plastic tarpaulins. Very long exposure appeared especially important for complete kill. Estivated Theba pisana (Muller) were much less resistant than C. barbara , with 6 lb for 10 hr being sufficient. Vacuum fumigation was much more effective against both snails. Methyl bromide at 40° to 55°F also appeared promising. Sulfuryl fluoride at 3 lb for 72 hr was effective at warm temperatures, but some Cochlicella survived 6 lb near 55°F. Hydrogen cyanide showed much promise at 2–3 lb for 72 hr, as did chloropicrin in preliminary tests at 1.5 lb for 48 hr. Survivors occurred with 5 lb acrylonitrilc-carbon tetrachloride (34 to 66% by vol) for 72 hr. Results with carbon disulphide, carbon tetrachloride, ethylene dibromide, methallyl chloride, hydrogen phosphide, and other chemicals are discussed. Resistance of estivated snails varied from year to year and was greatest the first 3 months after field collection. Some snails survived 18 months under warm, dry conditions, without food or water, when resistance was at a minimum.

Effect of Methyl Bromide and Hydrocyanic Acid Fumigation on the Germination of Corn Seed 1

Effect of Methyl Bromide and Hydrocyanic Acid Fumigation on the Germination of Corn Seed 1

Effect of Methyl Bromide and Hydrocyanic Acid Fumigation on the Germination of Rice1

Effect of Methyl Bromide and Hydrocyanic Acid Fumigation on the Germination of Rice1

Effect of Methyl Bromide and Hydrocyanic Acid Fumigation on the Germination of Oats1

Two varieties of oats, Kanota and Ventura, with a graded moisture range of 8, 10, 12, and 14% were fumigated with methyl bromide in 100-cubic-foot gastight chambers at an exposure period of 72 hours. Various dosages and temperatures were used. One variety of oats, Kanota, was fumigated with methyl bromide and hydrocyanic acid under varying conditions of temperature, exposure, and dosages of fumigant. One half of the fumigated samples of seed received one fumigation; the others were fumigated twice. Two series of germination tests were made, the first within 5 days following fumigation of seeds, and the second after 84 days of postfumigation storage at 50° F. Under the conditions of the experiments, the germination of oats was not affected by fumigation with hydrocyanie acid. Dosage, temperature, period of exposure, and the moisture content of seeds were variables found to be most important in contributing to injury from methyl bromide. Although oat seeds were relatively resistant to fumigation with methyl bromide, some injury did occur.