Methyl Bromide Fumigation Research Articles

Fumigation Activity of Ethyl Formate and Phosphine Against Tetranychus urticae (Acari: Tetranychidae) on Imported Sweet Pumpkin

This study investigated an alternative fumigant for imported sweet pumpkin. Laboratory fumigations with ethyl formate (EF) and phosphine (PH3) alone and in combination were conducted at different temperatures in 12-liter desiccators to determine their efficacy and synergism against adults and eggs of two-spotted spider mites (Tetranychus urticae Koch), a major pest of sweet pumpkins; larger scale fumigations with EF were also performed to evaluate the impact of EF fumigation on the postharvest quality of sweet pumpkin and EF absorption. EF fumigation of 4 h achieved 100% control of both adults and eggs at 10°C. Efficacy of EF also increased with temperature. Conversely, PH3 fumigation for 4 and 6 h was not effective against either adults or eggs, and no synergism between EF and PH3 was observed. In larger scale fumigation tests, EF at 60 g/m3 for 4 h resulted in 100% control of both adults and eggs at 10°C, without causing injury to the sweet pumpkins. These results suggest that EF has the potential to be a safe and effective alternative to methyl bromide fumigation for controlling two-spotted spider mites on sweet pumpkin.

Evaluation of allyl isothiocyanate as a soil fumigant against soil-borne diseases in commercial tomato (Lycopersicon esculentum Mill.) production in China.

Root-knot nematodes (Meloidogyne spp.), soil-borne diseases and weeds seriously reduce the commercial yield of tomatoes grown under protected cultivation in China. Allyl isothiocyanate (AITC), a natural product obtained from damaged Brassica tissues, was evaluated as a potential replacement for the fumigant methyl bromide (MB) for use in the greenhouse production of tomatoes in China. The dose-response assay indicates that AITC has high biological activity against major bacterial and fungal pathogens (EC50 of 0.225-4.199 mg L-1 ). The bioassay results indicate that AITC has good efficacy against root-knot nematodes (LC50 of 18.046 mg kg-1 ), and moderate efficacy against fungal pathogens (LC50 of 27.999-29.497 mg kg-1 ) and weeds (LC50 of 17.300-47.660 mg kg-1 ). The potting test indicates that AITC significantly improved plant vigor. Field trials indicate that AITC showed good efficacy against Meloidogyne spp. and Fusarium spp. (both ∼ 80%) as well as Phytophthora spp. and Pythium spp. (both ∼ 70%), and improved plant vigor and marketable yield. AITC used as a soil fumigant (30-50 g m-2 ) effectively controlled major bacterial and fungal pathogens, root-knot nematode, weeds and increased plant vigor, yield and farmers' income in tomato cultivated under protected agriculture in China. © 2018 Society of Chemical Industry.

Evaluation of Low-Temperature Phosphine Fumigation for Control of Oriental Fruit Fly in Loquat Fruit.

Oriental fruit fly, Bactrocera dorsalis (Hendel; Diptera: Tephritidae), is recognized as a quarantine pest and a threat to Chinese loquat (Eriobotrya japonica Lindl.) fruit exports. Since loquat fruit is very sensitive to methyl bromide (MB) fumigation and cold treatment, in this study, low-temperature phosphine (PH3) fumigation was investigated to develop an alternative phytosanitary treatment method. Tolerance tests showed that the third instar was the most tolerant of all life stages of B dorsalis to PH3 gas at 8°C. Toxicity assay with 500-3000 ppm PH3 and subsequent probit analysis showed that 2000 ppm PH3 was optimal for fumigation and 152.75 h of treatment duration were required to achieve 99.9968% mortality. In the verification test, 144 and 168 h of treatment duration with 2000 ppm PH3 completely killed 35,277 and 35,134 B. dorsalis third instars, respectively. However, 13 live larvae were found after 120 h of treatment. Furthermore, these treatments reduced fruit respiration rates while causing no adverse effects on other fruit quality parameters, including firmness, soluble solid content, and titratable acidity over 192 h storage at 8°C. The results strongly suggest that low-temperature PH3 fumigation could be used for the postharvest control of B. dorsalis in loquat fruit.

Use of Lard, Food Grade Propylene Glycol, and Polysaccharides in Infused Nets to Control Tyrophagus putrescentiae (Schrank; Sarcoptiformes: Acaridae) Infestation on Dry Cured Hams

Tyrophagus putrescentiae (Schrank) is controlled in the U.S. dry cured ham industry with methyl bromide (MB) fumigation. However, MB fumigation is being phased out of use since it is an ozone depleting substance. The objective of this research was to evaluate ham nets that were infused with lard, propylene glycol (PG) and polysaccharide coating for their efficacy at controlling mite infestations on dry cured ham cubes from hams that were aged for 4 to 6 mo. Results indicated that fewer T. putrescentiae (P < 0.05) were on ham cubes with treated nets containing PG when compared to the number of mites on ham cubes with untreated nets over 10 wk of storage. Lard infused nets without PG did not decrease the mite population (P > 0.05). The net without coating slowed the growth and reproduction of T. putrescentiae since net controls had fewer mites (P < 0.05) than controls without nets. Fungi were not present on ham cubes that were treated with PG-containing nets over 10 wk of storage with a few exceptions. In conclusion, lard and xanthan gum, or carrageenan + propylene glycol alginate treated nets containing the medium concentration of PG effectively inhibited mite reproduction and fungal growth on dry cured ham and could potentially be used in an integrated pest management program to control mites on dry cured hams.

Procedures of Laboratory Fumigation for Pest Control with Nitric Oxide Gas

Nitric oxide (NO) is a newly discovered fumigant for postharvest pest control. This paper provides detailed protocols for conducting NO fumigation on fresh products and procedures for residue analysis and product quality evaluation. An airtight fumigation chamber containing fresh fruit and vegetables is first flushed with nitrogen (N2) to establish an ultralow oxygen (ULO) environment followed by injection of NO. The fumigation chamber is then kept at a low temperature of 2 - 5 °C for a specified time period necessary to kill a target pest to complete a fumigation treatment. At the end of a fumigation treatment, the fumigation chamber is flushed with N2 to dilute NO prior to opening the chamber to ambient air to prevent the reaction between NO and O2, which produces NO2 and may damage delicate fresh products. At different times after NO fumigation, NO2 in headspace and nitrate and nitrite in liquid samples were measured as residues. Product quality was evaluated after 2 weeks of post-treatment cold storage to determine effects of NO fumigation on product quality. Keeping O2 from reacting with NO is critical to NO fumigation and is an important part of the protocols. Measuring NO levels is challenging and a practical solution is provided. Possible protocol modifications are also suggested for measuring NO levels in the fumigation chambers as well as residues. NO fumigation has the potential to be a practical alternative to methyl bromide fumigation for postharvest pest control on fresh and stored products. This publication is intended to assist other researchers in conducting NO fumigation research for postharvest pest control and accelerating the development of NO fumigation for practical applications.

Procedures of Laboratory Fumigation for Pest Control with Nitric Oxide Gas

Nitric oxide (NO) is a newly discovered fumigant for postharvest pest control. This paper provides detailed protocols for conducting NO fumigation on fresh products and procedures for residue analysis and product quality evaluation. An airtight fumigation chamber containing fresh fruit and vegetables is first flushed with nitrogen (N2) to establish an ultralow oxygen (ULO) environment followed by injection of NO. The fumigation chamber is then kept at a low temperature of 2 - 5 °C for a specified time period necessary to kill a target pest to complete a fumigation treatment. At the end of a fumigation treatment, the fumigation chamber is flushed with N2 to dilute NO prior to opening the chamber to ambient air to prevent the reaction between NO and O2, which produces NO2 and may damage delicate fresh products. At different times after NO fumigation, NO2 in headspace and nitrate and nitrite in liquid samples were measured as residues. Product quality was evaluated after 2 weeks of post-treatment cold storage to determine effects of NO fumigation on product quality. Keeping O2 from reacting with NO is critical to NO fumigation and is an important part of the protocols. Measuring NO levels is challenging and a practical solution is provided. Possible protocol modifications are also suggested for measuring NO levels in the fumigation chambers as well as residues. NO fumigation has the potential to be a practical alternative to methyl bromide fumigation for postharvest pest control on fresh and stored products. This publication is intended to assist other researchers in conducting NO fumigation research for postharvest pest control and accelerating the development of NO fumigation for practical applications.

Occupational pesticide exposure and subclinical hypothyroidism among male pesticide applicators

ObjectivesAnimal studies suggest that exposure to pesticides may alter thyroid function; however, few epidemiologic studies have examined this association. We evaluated the relationship between individual pesticides and thyroid function in...

Infrared detection of codling moth larvae in apples


 
 
 Codling moth, Cydia pomonella (Lepidoptera: Tortricidae), is a key pest of apples exported from New Zealand and is dif cult to control at levels required to ensure quarantine security demanded by many countries. Market access for New Zealand apples into countries with strict codling-moth quarantine regulations currently relies on methyl bromide fumigation combined with cold treatment (e.g. Japan) or the use of a rigorous systems approach (e.g. Taiwan). Detection of codling moth in apples would enable the very few apples in the packhouse with codling moth to be graded out. In this study, a commercially available Compac Spectrim grading system was used to determine if codling moth entry holes could be detected. This system provides high-clarity images through enhanced lighting and optics, as well as using various infrared wavelengths to target different defects and machine-learning algorithms to differentiate defects. Apples infested with first- or third-instar codling moth larvae were processed through the Spectrim machine. The system successfully identi ed 100% of apples infested with rst- instar larvae and 96% of apples infested with third-instar larvae. Additionally, damage caused by the two life stages was able to be differentiated.
 
 

Rhizosphere microorganisms affected by soil solarization and cover cropping in Capsicum annuum and Phaseolus lunatus agroecosystems

Field experiments were conducted to evaluate the effects of soil solarization or cover crop on bell pepper (Capsicum annuum) and lima bean (Phaseolus lunatus) rhizosphere microorganisms. In Experiment I, flat surface solarization (FSS), raised bed solarization (RBS), cowpea (Vigna unguiculata) cover crop alone (CP), and the combination of cowpea cover crop followed by raised bed soil solarization (CP+RBS) were compared with methyl bromide fumigation (MB) and an untreated control (UTC) for effects on rhizosphere bacteria and fungi on bell pepper. In Experiment II, effects of cover crop on rhizosphere microorganisms were examined on lima bean in a 3×3 split-plot experiment with three summer cover crop treatments: sunn hemp (SH) (Crotalaria juncea), cowpea (CP), and fallow (F) as main plots, and three organic amendments: sunn hemp hay (SHH), cowpea hay (CPH), and no hay (NH) as subplots. Rhizosphere bacteria including siderophore producers, gram-positive spore-formers, and fluorescent pseudomonads were assessed, as well as two fungi, Fusarium oxysporum and Rhizoctonia solani. In year 1 of Experiment I, CP+RBS reduced F. oxysporum and R. solani in the rhizosphere, resulting in levels similar to those in MB fumigation. This was not observed in year 2. Heavy rainfall in year 2 resulted in a severe outbreak of Pythium on bell pepper, which was most destructive in MB fumigated plots. Effects of solarization and cover crop on rhizosphere bacteria also differed between years. Fluorescent pseudomonads were abundant across treatments in year 1, but were greatly reduced in year 2, when the Pythium outbreak occurred. In Experiment II, populations of rhizobacteria on lima bean were not affected by cover crop in either year. At the end of year 1, isolation of R. solani from lima bean roots increased in SHH plots. SH cover crop reduced gram-positive spore forming bacteria and fluorescent pseudomonads. In year 2, CP followed by CPH had higher levels of fungi and bacteria than CP followed by either NH or SHH. Overall, cover crop amendments did not result in consistent enhancement of rhizobacteria, and some treatments resulted in increased abundance of pathogenic fungi. The most consistent treatment for reducing rhizosphere fungal populations was MB.

Rapid Screening of Sulfuryl Fluoride as a Potential Phytosanitary Treatment for a Broad Selection of Fungi Relevant to Forestry

Abstract Increasing restrictions on the use of methyl bromide have created an urgent need to find suitable replacements that are effective in eliminating exotic pest establishments via trade in wood products. Efficacy data for established phytosanitary fumigants have primarily focused on arthropods and nematodes, whereas limited information exists for plant pathogens and fungi relevant to forestry. A rapid screening process was developed to evaluate efficacy and compare relative tolerance to fumigation treatments for a broad selection of relevant fungi under laboratory conditions. Sulfuryl fluoride (SF) fumigations were conducted in 10-liter glass chambers at six target concentrations (40 to 240 mg liter−1) at 15°C and 20°C for 24-, 48-, and 72-hour exposure times against 23 fungal species represented with 35 isolates. Fungi were grown on sterilized barley grain and then distributed in felt-covered borosilicate glass tubes to allow uninhibited gas penetration during fumigation while minimizing the risk of fungal contamination. This allowed simultaneous testing of numerous species and isolates, followed by 100 percent recovery of controls without contamination. Results demonstrate that SF is an effective fumigant for a broad range of fungi. Several fungi and isolates were found to consistently be among the most tolerant to the fumigant treatment. These species may serve as a benchmark for screening SF in fumigations of logs and other wood products. Methods developed here will be useful in efficacy screening of other methyl bromide fumigant alternatives.

Degradation of dimethyl disulphide in soil with or without biochar amendment.

Dimethyl disulphide (DMDS) is a new and effective alternative to methyl bromide for soil fumigation. The effect of biochar on the fate of DMDS in soil is not fully understood. The objective of this study was to determine the degradation kinetics of DMDS in different soils and evaluate the effect of biochar amendment on DMDS degradation using incubation experiments. The degradation half-life of DMDS was between 1.05 and 6.66 days under non-sterile conditions, and 12.63 to 22.67 days under sterile conditions in five types of soil. Seven out of the eight tested biochar amendments (BC-2 to BC-8) delayed the degradation of DMDS in soil, increasing the half-life of DMDS in Fangshan soil from 1.05 to 1.16-5.87 days following amendment with 1% (w/w) biochar. The degradation rate of DMDS in Fangshan soil accelerated as the amendment rate of BC-1 increased, and decreased as the amendment rate of BC-7 increased. Biodegradation is an important degradation route for DMDS in soil, and DMDS degraded faster in alkaline soil. The effects of biochar amendments on DMDS degradation in soil are determined by complex multiple factors (such as surface area, pH and physicochemical composition), rather than by any single property of biochar. © 2017 Society of Chemical Industry.

Application of Food-Grade Ingredients to Nets for Dry Cured Hams to Control Mite Infestations

Infestations of Tyrophagus putrescentiae (Schrank; Sarcoptiformes: Acaridae), known as the ham mite, may occur on dry cured hams during the aging process. The fumigant methyl bromide is currently used to control mite infestations, but it will eventually not be available for use since it contributes to the depletion of the ozone layer. The use of ham nets treated with xanthan gum, carrageenan, propylene glycol alginate, and propylene glycol food-grade ingredients on mite orientation to or oviposition on treated or untreated ham cubes, and mite reproduction and population growth over a 10-wk period was evaluated. Behavioral tests indicated that more than 95% of the mites oriented to the ham cubes that were wrapped in untreated nets when compared to treated nets and no eggs were laid on the latter. The reproduction assays demonstrated that there were fewer (P < 0.05) T. putrescentiae produced over a 2-wk period on ham cubes covered with both gum and propylene glycol treated nets, when compared to the untreated or gum-only treated nets over the 10-wk storage period of the experiment. Medium and high concentrations of propylene glycol treatments showed the lowest reproductive rates of mites. No more than 4 mites could be found on each of these treatments in comparison to 200 to 300 mites that were recorded on the untreated hams. This study demonstrated efficacy of using the nets treated with food-grade ingredients during ham aging to control mite infestations on a laboratory scale. Further research will be conducted to determine the effectiveness of the same treated nets on whole hams in commercial aging rooms.

Impact of Oriental Fruit Fly Postharvest Treatments on Avocado

The detection in August 2015 of the Oriental Fruit Fly (Bactrocera dorsalis Hendel, Diptera: Tephritidae) in the Redland area in Miami-Dade County, Florida triggered a quarantine that restricted the movement of fruit fly host material in an approximately 99-square mile (256-square kilometer) area. The quarantine affected 4000 acres of fruit bearing commercial avocado groves. Approved post-harvest treatments for B. dorsalis and avocado included in the USDA Treatment Manual were acceptable for immediate certification and movement of fresh avocados from the quarantine area. However, it was unknown if Florida avocados would meet quality standards (US combination grade) after the treatments. Three post-harvest treatments that combine methyl bromide fumigation and cold storage periods were tested on six avocado varieties from Florida. The treatments differed in the durations of the fumigation and cold treatment periods. A seven day transit period at 8.3°C (47°F) was added to account for the time when the fruit leaves the packing house until it is sold by retailers. None of the six varieties had met the US combination grade after the treatments and transit period. Treated fruit exhibited both internal (pulp) and external (skin) damage. Damage was attributed to the fumigation component of the treatment, but the six varieties tolerated the cold portion of the treatment. Damage by fumigation ranged from 26% - 100%. In general, the longer the fumigation period the worse the effect. The need for alternative post-harvest treatments for Florida avocados is discussed.

Efficacy of Nitric Oxide Fumigation for Controlling Codling Moth in Apples.

Nitric oxide (NO) fumigation under ultralow oxygen (ULO) conditions was studied for its efficacy in controlling codling moth and effects on postharvest quality of apples. NO fumigation was effective against eggs and larvae of different sizes on artificial diet in 48 h treatments. Small larvae were more susceptible to nitric oxide than other stages at 0.5% NO concentration. There were no significant differences among life stages at 1.0% to 2.0% NO concentrations. In 24 h treatments of eggs, 3.0% NO fumigation at 2 °C achieved 100% egg mortality. Two 24 h fumigation treatments of infested apples containing medium and large larvae with 3.0% and 5.0% NO resulted in 98% and 100% mortalities respectively. Sound apples were also fumigated with 5.0% NO for 24 h at 2 °C to determine effects on apple quality. The fumigation treatment was terminated by flushing with nitrogen and had no negative impact on postharvest quality of apples as measured by firmness and color at 2 and 4 weeks after fumigation. This study demonstrated that NO fumigation was effective against codling moth and safe to apple quality, and therefore has potential to become a practical alternative to methyl bromide fumigation for control of codling moth in apples.

Effect of phytosanitary irradiation and methyl bromide fumigation on the physical, sensory, and microbiological quality of blueberries and sweet cherries.

In the article “Effect of phytosanitary irradiation and methyl bromide fumigation on the physical, sensory, and microbiological quality of blueberries and sweet cherries” (DOI: 10.1002/jsfa.7648)1, published in Wiley Online Library on 15 March 2016 and in the Journal of the Science of Food and Agriculture 96: 4382–4389, there are two authors missing from the author's list. The correct list of authors and their affiliations are as follows: Karen Thanga, Kimberlee Aua, Vikalp Joisara, Kimberlyn Teha, Cyril Rakovskib and Anuradha Prakasha a Food Science Program, Chapman University, One University Drive, Orange, CA 92866, USA b Faculty of Mathematics, Chapman University, One University Drive, Orange, CA 92866, USA The authors apologise for this oversight.

Sensitivity of different life stages of Indian meal moth Plodia interpunctella to gaseous chlorine dioxide

Gaseous chlorine dioxide (ClO2), a possible alternative to the fumigant methyl bromide, is a strong disinfecting agent that has strong oxidizing properties and penetration ability. The Indian meal moth, Plodia interpunctella, is one of the most important insect pests of stored food, but its sensitivity to gaseous ClO2 at different life stages has not yet been studied. We exposed all the life stages of P. interpunctella (i.e., eggs, larvae, pupae, and adults) to ClO2 at different concentrations for different time periods. The results showed that 100 ppm and 200 ppm ClO2 for 48 h and 24 h, respectively, resulted in 100% mortality of all P. interpunctella life stages. The order of sensitivity of P. interpunctella to gaseous ClO2 was: egg > larva > pupa at 50 ppm and 100 ppm, and egg > pupa > larva at 200 ppm. The gas treatment affects the subsequent life stage of P. interpunctella: the gas-treated larvae fail to pupate or emerge as adults. These results suggest that gaseous ClO2 is a possible alternative to methyl bromide, and it can effectively control all stages of P. interpunctella.

Strawberry growers wavered over methyl iodide, feared public backlash

Methyl iodide, once promoted as a suitable alternative to methyl bromide for soil fumigation in strawberry systems, was withdrawn from the market in 2012 after a contentious regulatory battle that revolved around its high toxicity. At the time of its withdrawal, Arysta LifeScience, the maker of the chemical, claimed that it was no longer economically viable. In this study, I investigated what made the chemical nonviable, with a specific focus on growers’ nonadoption of it. Interviews with strawberry growers in the four top California strawberry-growing counties revealed that growers’ decisions not to use it were primarily related to public disapproval, although the continued availability of methyl bromide and other fumigants played a contributing role by making adoption less urgent. The study results suggest that policies in place during the methyl bromide phaseout did not strongly encourage the development and extension of less toxic alternatives, which undermined the strawberry industry's position.

Fumigant Use for Strawberry Production in Europe: The Current Landscape and Solutions

ABSTRACTThe impact of methyl bromide (MB) phase-out on important fruit and nursery industries in the EU (2005/2008) has been significant. Under EU Regulation 1107/2009, MB fumigant alternatives 1,3-dichloropropene and chloropicrin were also phased out (in 2010 and 2013, respectively) while dazomet, metam sodium, and potassium were re-approved with crucial restrictions of rates and years of application. However, currently an EU Member State may authorize use of these phased-out fumigants for 120 days/year. This exemption has been used for strawberry (fruit and nursery production) and other crops in Spain, Italy, Belgium, France, UK, Cyprus, Malta, and Greece in recent years. To provide an update of the current situation, a comprehensive survey of 41 European and other industries has been completed. Most of them use crop rotation as the main pest management solution. Non-chemical solutions, in particular soilless cultivation, are important in the UK, Ireland, France, the Netherlands, and Belgium. Chemical fumigation is still important in Spain, Italy, Morocco, Turkey, France, and Belgium.

The effects of postharvest carbon dioxide and a cold storage treatment on Tuta absoluta mortality and tomato fruit quality

Tuta absoluta is an invasive pest species that affects tomatoes and other solanaceous crops and is found in Europe and other Mediterranean areas. Hitherto, fumigation with methyl bromide is the only measure used to control this pest during the postharvest period. Because of methyl bromide phytotoxicity and health, safety and environmental concerns, alternatives to this product need to be investigated. Therefore, the objective of this study was to determine the ability of T. absoluta to complete its preimaginal development on tomato fruit during the postharvest period and to evaluate the effectiveness of different supra atmospheric carbon dioxide (CO2) levels and cold storage treatments on T. absoluta control. T. absoluta was unable to complete its development from egg to adult on fruit of three tomato varieties. In contrast, T. absoluta completed its preimaginal development when more mature larvae were provided with the tomato fruit. The exposure of T. absoluta to a modified atmosphere of 95% CO2 at 25°C for 48h was effective for the control of all life stages, but negatively affect fruit quality. An increment in the exposure time to 72h was necessary in order to obtain the same level of control at 40% CO2. A cold storage treatment at 1°C for a total of 10days was also effective for the control of the T. absoluta eggs. These two treatments did not negatively affect the quality of the fruit. Therefore, these appear to be effective alternatives to postharvest methyl bromide fumigation and future studies need to be planned to validate the commercial feasibility of these findings.

Efficacy of selected pesticides against Tyrophagus putrescentiae (Schrank): influences of applied concentration, application substrate, and residual activity over time

Dry-cured ham is protected from arthropod infestations using the fumigant methyl bromide. Tyrophagus putrescentiae (Schrank), known as the cheese or ham mite, decreases the quality and quantity of dry-cured hams during the aging process and is a serious economic threat to dry-cured ham companies. Methyl bromide is a strong ozone-depleting substance that is scheduled to be phased out from most uses in the near future. Consequently, developing effective, feasible, and economic alternatives to methyl bromide is the main purpose of the current project. More than ten registered residual pesticides were assessed for toxicity with glass vials treated with different concentrations. Twenty mites were transferred to each vial for 24 h of exposure on contact. Persistence of three of these residual pesticides was evaluated over a 2-month period by applying the recommended label rates to different surfaces. Results indicated that the commercial products of deltamethrin plus chlorpyrifos-methyl, chlorphenapyr, and malathion showed promising results for contact toxicity against mites, and chlorphenapyr was highly effective at very low concentrations. Chlorphenapyr was the only pesticide applied to metal, concrete, and wood that was effective at controlling ham mites for 8 weeks. These pesticides are currently registered for use in similar contexts, so they could be considered as new potential control measures for ham mites in ham plants.