Methyl bromide as a quarantine treatment for Anoplophora glabripennis (Coleoptera: Cerambycidae) in regulated wood packing material

Anoplophora glabripennis (Motschulsky), has recently (since 1996) established in limited infestations near several cities in the United States. A. glabripennis was probably introduced into the United States with solid wood packing or dunnage. During 2001, we evaluated the current APHIS Schedule T404-b-1-1 for methyl bromide (MeBr) fumigation. Fumigations were conducted in 432-liter Lexan chambers inside a 6.1-m refrigerated container. Each fumigation consisted of 12 high-moisture, naturally infested Populus spp. timbers. We fumigated wood for 24 h at 4.4 degrees C (80 g/m3), 10.0 degrees C (64 g/m3), 15.6 degrees C (56 g/m3), and 21.1 degrees C (48 g/m3). All schedule doses resulted in 100% kill of A. glabripennis larvae. During 2002, we conducted additional fumigations to determine the basic toxicity of MeBr to A. glabripennis larvae in solid wood timbers of 10 by 10 by 115-cm size. Probit analysis estimated the CxT product at 99.0, 99.9, 99.99, and 99.99683% kill (probit-9). The probit-9 values for CxT were 1,196.1, 918.7, 642.4, and 362.4 g-h/m3 at 4.4, 10.0, 15.6, and 21.1 degrees C, respectively. Applied doses to achieve this level of control were estimated to be 119.6, 82.7, 56.0, and 32.2 g/m3, respectively. These applied doses are satisfactory for wood as a commodity with wood load factors of approximately 25% and may be higher than necessary for container fumigation where sorptive wood load as crating or pallets may only be 5% or less. The APHIS Schedule T404-b-1-1 is adequate if extended for 24 h and should be amended to include intermediate doses at 10.0 and 15.6 degrees C, thus reducing the use of MeBr at these temperatures.     

Sulfuryl fluoride as a quarantine treatment for Anoplophora glabripennis (Coleoptera: Cerambycidae) in regulated wood packing material

The Asian longhorned beetle, Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), was probably introduced into the United States from China with solid wood packing and dunnage during the 1980s, and it has recently become established in limited infestations near several major cities in the United States. Regulated wood packing material (RWPM) arriving in the United States from China is required to undergo fumigation with methyl bromide (MeBr), to be heat treated, or kiln dried. Sulfuryl fluoride (SF) is a candidate fumigant to replace MeBr under certain conditions. SF fumigations were conducted in 432-liter Lexan chambers held in a 6.1-m (20-foot) refrigerated container for temperature control. Each fumigation consisted of 12 Populus spp. 10- by 10- by 115-cm timbers, of high moisture content, naturally infested with Asian longhorned beetle. During 2001, we fumigated wood for 24 h at a range of doses (20-112 g/m3) and temperatures (4.4, 10.0, 15.6, and 21.1 degrees C) and subjected the data to probit analysis. Confirmatory fumigations were conducted at doses of 120 and 104 g/m3 at temperatures of 10.0 and 15.6 or 21.1 degrees C, respectively, which resulted in complete kill of all larvae. Pupae that became available later in the year as temperatures warmed were fumigated at 15.6 and 21.1 degrees C with 104 g/m3, which resulted in complete pupal mortality. The next year (2002), we conducted 24-h fumigations with doses of 116 g/m3 at 4.4 and 10.0 degrees C with cold-harvested wood infested with cold-acclimated larvae. Cold-acclimated larvae required much higher concentration times time (CxT) product for control at 4.4 and 10.0 degrees C compared with nonacclimated larvae. Sulfuryl fluoride treatments at a dose of 104 g/m3 and temperature of 15.6 degrees C and above and that achieved a CxT product of 1,095 g-h/m3 or above are recommended for RWPM infested with Asian longhorned beetle larvae and pupae.     

Low-temperature methyl bromide fumigation of emerald ash borer (Coleoptera: Buprestidae) in ash logs

Ash (Fraxinus spp.) logs, infested with fully developed, cold-acclimated larval and prepupal emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), were fumigated with methyl bromide (MeBr) at 4.4 and 10.0 degrees C for 24 h. Concentrations X time dosages of MeBr obtained were 1579 and 1273 g-h/m3 (24-h exposure) at 4.4 and 10.0 degrees C after applied doses of 112 and 96 g/m3, respectively. MeBr concentrations were simultaneously measured with a ContainIR infrared monitor and Fumiscope thermal conductivity meter calibrated for MeBr to measure the effect of CO2 on Fumiscope concentration readings compared with the infrared (IR) instrument. The presence of CO2 caused false high MeBr readings. With the thermal conductivity meter, CO2 measured 11.36 g/m3 MeBr per 1% CO2 in clean air, whereas the gas-specific infrared ContainIR instrument measured 9.55% CO2 as 4.2 g/m3 MeBr (0.44 g/m3 per 1% CO2). The IR instrument was 0.4% as sensitive to CO2 as the thermal conductivity meter. After aeration, fumigated and control logs were held for 8 wk to capture emerging beetles. No A. planipennis adults emerged from any of the fumigated logs, whereas 262 emerged from control logs (139 and 123/m2 at 4.4 and 10.0 degrees C, respectively). An effective fumigation dose and minimum periodic MeBr concentrations are proposed. The use of a CO2 scrubber in conjunction with nonspecific thermal conductivity instruments is necessary to more accurately measure MeBr concentrations.     

Bacterial Oxidation of Methyl Bromide in Fumigated Agricultural Soils

The oxidation of [(sup14)C]methyl bromide ([(sup14)C]MeBr) to (sup14)CO(inf2) was measured in field experiments with soils collected from two strawberry plots fumigated with mixtures of MeBr and chloropicrin (CCl(inf3)NO(inf2)). Although these fumigants are considered potent biocides, we found that the highest rates of MeBr oxidation occurred 1 to 2 days after injection when the fields were tarped, rather than before or several days after injection. No oxidation of MeBr occurred in heat-killed soils, indicating that microbes were the causative agents of the oxidation. Degradation of MeBr by chemical and/or biological processes accounted for 20 to 50% of the loss of MeBr during fumigation, with evasion to the atmosphere inferred to comprise the remainder. In laboratory incubations, complete removal of [(sup14)C]MeBr occurred within a few days, with 47 to 67% of the added MeBr oxidized to (sup14)CO(inf2) and the remainder of counts associated with the solid phase. Chloropicrin inhibited the oxidation of MeBr, implying that use of this substance constrains the extent of microbial degradation of MeBr during fumigation. Oxidation was by direct bacterial attack of MeBr and not of methanol, a product of the chemical hydrolysis of MeBr. Neither nitrifying nor methane-oxidizing bacteria were sufficiently active in these soils to account for the observed oxidation of MeBr, nor could the microbial degradation of MeBr be linked to cooxidation with exogenously supplied electron donors. However, repeated addition of MeBr to live soils resulted in higher rates of its removal, suggesting that soil bacteria used MeBr as an electron donor for growth. To support this interpretation, we isolated a gram-negative, aerobic bacterium from these soils which grew with MeBr as a sole source of carbon and energy.     

Evaluation of the Efficacy of Methyl Bromide in the Decontamination of Building and Interior Materials Contaminated with Bacillus anthracis Spores

The primary goal of this study was to determine the conditions required for the effective inactivation of Bacillus anthracis spores on materials by using methyl bromide (MeBr) gas. Another objective was to obtain comparative decontamination efficacy data with three avirulent microorganisms to assess their potential for use as surrogates for B. anthracis Ames. Decontamination tests were conducted with spores of B. anthracis Ames and Geobacillus stearothermophilus, B. anthracis NNR1Δ1, and B. anthracis Sterne inoculated onto six different materials. Experimental variables included temperature, relative humidity (RH), MeBr concentration, and contact time. MeBr was found to be an effective decontaminant under a number of conditions. This study highlights the important role that RH has when fumigation is performed with MeBr. There were no tests in which a ≥6-log₁₀ reduction (LR) of B. anthracis Ames was achieved on all materials when fumigation was done at 45% RH. At 75% RH, an increase in the temperature, the MeBr concentration, or contact time generally improved the efficacy of fumigation with MeBr. This study provides new information for the effective use of MeBr at temperatures and RH levels lower than those that have been recommended previously. The study also provides data to assist with the selection of an avirulent surrogate for B. anthracis Ames spores when additional tests with MeBr are conducted.     

Methyl bromide as a microbicidal fumigant for tree nuts.

Methyl bromide (MeBr) has broad microbicidal activity, but its use as a disinfectant for food is limited by the resulting bromide residues. Increasing the MeBr concentration, exposure temperature, or exposure period of a treatment tended to increase both the microbicidal efficacy of MeBr and the bromide residues. Its sporicidal activity was less at high than at low relative humidity within the range of 20 to 99%. Both the efficacy and the resulting residues of a MeBr treatment varied inversely with the load of product in a fumigation chamber due to sorption of the fumigant. Fumigation tests with almond kernels inoculated with Escherichia coli or Salmonella typhimurium indicated that MeBr can be used to disinfect whole nut kernels without resulting in excessive bromide residues, although the MeBr level necessary is higher than that normally used for insect control.     

Methyl bromide as a microbicidal fumigant for tree nuts.

Methyl bromide (MeBr) has broad microbicidal activity, but its use as a disinfectant for food is limited by the resulting bromide residues. Increasing the MeBr concentration, exposure temperature, or exposure period of a treatment tended to increase both the microbicidal efficacy of MeBr and the bromide residues. Its sporicidal activity was less at high than at low relative humidity within the range of 20 to 99%. Both the efficacy and the resulting residues of a MeBr treatment varied inversely with the load of product in a fumigation chamber due to sorption of the fumigant. Fumigation tests with almond kernels inoculated with Escherichia coli or Salmonella typhimurium indicated that MeBr can be used to disinfect whole nut kernels without resulting in excessive bromide residues, although the MeBr level necessary is higher than that normally used for insect control.     

Toxicity of ethanedinitrile to Anoplophora glabripennis (Coleoptera: Cerambycidae) larvae

The mortality of naked Anoplophora glabripennis Motschulsky (Coleoptera: Cerambycidae) larvae exposed to ethanedinitrile (cyanogen; C2N2) varied with temperature, time of exposure, and dose of ethanedinitrile. The concentration x time (Ct) product of ethanedinitrile over a range of temperatures (4.4, 10.1, 15.6, and 20.1 degrees C) decreased with increasing temperature, for both 3- and 6-h exposures. The Ct products varied with time of exposure at different temperatures. The variations in mortality at different temperatures are described with a slope ratio (Y = [slope]6h/ [slope]3h). At different temperatures, the concentration of ethanedinitrile and the duration of exposure play different roles in killing A. glabripennis larvae. These results suggest the control of A. glabripennis larvae within wood is achievable.     

The Disinfecting Activity of Methyl Bromide on Various Microbes and Infected Materials under Controlled Conditions

S ummary : Various micro-organisms were exposed to methyl bromide (MeBr) gas at concentrations of 20–40 mg/l for 20 h at 25°. A significant reduction was obtained in the number of viable bacteria and Aspergillus fumigatus spores, both in the dry form and in semifluid faeces, but no reduction was detected either in dried Bacillus subtilis spores or in one of the bacteriophages tested. The investigation indicates that MeBr is less effective against certain viruses, bacteria and fungi than against coccidial oocysts. The results suggest that fumigation of commercial poultry houses with these concentrations of MeBr may not, in all circumstances, provide the overall reduction of poultry pathogens desired.     

Impacts of chipping on surrogates for the longhorned beetle Anoplophora glabripennis (Coleoptera: Cerambycidae) in logs

As part of the eradication program for recent introductions of the longhorned beetle Anoplophora glabripennis (Motschulsky) in the United States, wood from infested trees is chipped and incinerated. Two tests were conducted to evaluate the efficiency of chipping wood from infested trees on the survival of the beetle. In the first test, plastic worms were used as surrogates for larvae of the beetle. Plastic worms of different sizes were placed in holes drilled in logs of sugar maple, Acer saccharum Marsh. In a second test, in addition to plastic worms, we used different instars and pupae of gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae); larvae of the beetle Phyllophaga annina Lewis (Coleoptera: Scarabaeidae); and larvae of an unidentified weevil (Coleoptera: Curculionidae). Although chipping did not result in an obvious damage to all plastic worms, it did kill all larvae and pupae of insects placed in holes of maple logs. The overall recovery rate (percent recovered) for the plastic worms was 96% in the first (1997) test, and 71 and 98% for 10 and 40 mm long plastic worms in the second (1998) test, respectively. Logistic regression analysis of the data from the first experiment indicates that larger worms receive more severe damage. Size of logs did not have a significant effect on the level of damage received by plastic worms. All recovered insects were severely damaged after chipping logs and we could not determine recovery rates. Results of the two tests indicate that chipping wood from infested trees without incineration of the resulting chips provides a highly effective method for destroying wood inhabiting insect pests such as A. glabripennis. The elimination of incineration saves considerable resources while effectively eliminating risks associated with movements of wood containing living wood-boring insects.     

The use and Development of America’s Forest Resources

The “supply-demand” situation for wood in the United States is reviewed. In the immediate future, no shortage of wood is expected, but there is some disagreement about whether or not we will face shortages by the year 2000. The concept of multiple use and the element of time in the production function further complicate an already complicated planning problem. Increased ability to (1) modify site (use of fertilizers, insect, disease, and fire control), (2) develop improved trees, (3) use mechanized equipment, and (4) develop better information and analytical methods as aids in decision making will mean a continuing shift away from our previous ideas about wood as a wild resource.     

Methyl bromide fumigation for the control of Aspergilli and Penicillia in stored grains

Fumigation with methyl bromide (MeBr) at a concentration of 120 mg/1 maintained for 4 h at 25°C caused 100% mortality of spores of Aspergillus ochraceus, A. flavus, Penicillium citrinum, P. chrysogenum and P. cyclopium. However, 40% of an A. niger spore population retained its viability after this treatment. Increasing the duration of fumigation to 24 h at a concentration of 40 mg/1 MeBr caused 100% spore mortality of all fungi tested. Total growth inhibition of 24 h-old mycelia was achieved with 40 mg/1 for 24 h or 120 mg/1 for 4 h. These concentrations for the same period of exposure were not inhibitory for 7-day-old mycelia of any of the fungi tested. In A. niger-inoculated wheat grains fumigated with 100 mg/1 MeBr for 24 h, 20% yielded fungal contaminants after 16 days of storage and 100% after 29 days. There was a marked drop in the percent germination of the grains after fumigation, whereas the free fatty acids level was higher than in unfumigated grain. The results of the in vivo study suggest that MeBr given at a commercial dosage for 24 h is not only ineffective in destroying the internal inocula of wheat grains but also enables their subsequent development by weakening the resistance of grains to fungal attack.     

Strain IMB-1, a Novel Bacterium for the Removal of Methyl Bromide in Fumigated Agricultural Soils

A facultatively methylotrophic bacterium, strain IMB-1, that has been isolated from agricultural soil grows on methyl bromide (MeBr), methyl iodide, methyl chloride, and methylated amines, as well as on glucose, pyruvate, or acetate. Phylogenetic analysis of its 16S rRNA gene sequence indicates that strain IMB-1 classes in the alpha subgroup of the class Proteobacteria and is closely related to members of the genus Rhizobium. The ability of strain IMB-1 to oxidize MeBr to CO₂ is constitutive in cells regardless of the growth substrate. Addition of cell suspensions of strain IMB-1 to soils greatly accelerates the oxidation of MeBr, as does pretreatment of soils with low concentrations of methyl iodide. These results suggest that soil treatment strategies can be devised whereby bacteria can effectively consume MeBr during field fumigations, which would diminish or eliminate the outward flux of MeBr to the atmosphere.Methyl bromide (MeBr) is a fumigant used in the cultivation of selected fruits, vegetables, and flowers and in the preservation of stored grains and structures. Use of MeBr as a pesticide increases the yield and quality of crops without leaving behind toxic residues characteristic of more complex organopesticides. However, because bromine released from MeBr destroys stratospheric ozone (18, 22, 29, 33), its use will be eliminated in the United States and elsewhere under the auspices of the Clean Air Act and the Montreal Protocol unless effective mechanisms which prevent its escape to the atmosphere can be found (36). Currently, much uncertainty exists with regard to the tropospheric residence time (τ) of MeBr, a factor which is used to calculate its ozone degradation potential (2). Estimates of τ range from ∼1.7 years when only oxidation by tropospheric OH radicals is considered (22) to less than 1.2 years when oceanic sinks are factored in (20). The discovery that soil bacteria oxidize MeBr from the atmosphere, when quantified and combined with the two preceding sinks, lowers τ to ∼0.8 years (32). Chemical destruction of MeBr occurs by hydrolysis, exchange with other halides, and reaction with organic matter (8, 9, 12), but its destruction by microorganisms has been noted in soils and aquatic environments (3, 16, 17a, 19, 23, 27, 28, 32). In aerobic environments, MeBr is oxidized to CO₂ and Br⁻ (3, 16, 23, 27).Bacterial oxidation of MeBr in soils has been reported both at very low (∼5 to 15 parts per trillion) ambient atmospheric mixing ratios (17a) and at the very high concentrations employed for field fumigation (23). The relative contributions that chemical reactions and bacterial oxidation make to the destruction of MeBr during agricultural fumigation are not yet known, but their combined effect will constrain the emissions of MeBr from soils. Reported destruction of MeBr within the soil matrix, as evidenced by the accumulation of Br⁻, can be substantial and account for as much as 39 to 70% of the applied MeBr in some cases (39, 40). Physical manipulations (e.g., soil compaction and deeper injection of MeBr) have been proposed to increase the retention time of MeBr within the soil matrix, thereby allowing for its more extensive degradation and subsequent decrease in its outward flux to the atmosphere (13). In addition, use of thicker, impermeable covering tarps has been proposed to reduce losses (14, 37), as has the substitution of methyl iodide for MeBr (11, 25). However, enhancement of microbial degradation of MeBr while it is present in the soil matrix may also be a means to eliminate emissions. This could be achieved by exploiting the ability of certain soil bacteria that use MeBr as a carbon and energy source (23). Here, we report further details on the characteristics of such an isolate (23), which we designate strain IMB-1. We demonstrate how the properties of IMB-1 can be used to greatly accelerate the oxidation of MeBr in fumigated soils. Because agricultural field fumigation represents the largest source of anthropogenic emissions of MeBr to the atmosphere, it is at least possible in theory that the overall goal of eliminating most human-derived emission of MeBr could be achieved by in situ biodegradation of this substance.     

Laboratory evaluation of the toxicity of systemic insecticides for Control of Anoplophora glabripennis and Plectrodera scalator (Coleoptera: Cerambycidae)

Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae) is one of the most serious nonnative invasive forest insects discovered in North America in recent years. A. glabripennis is regulated by federal quarantines in the United States and Canada and is the subject of eradication programs that involve locating, cutting, and chipping all infested trees. Other control methods are needed to aid in eradication and to form an integrated management program in the event eradication fails. We conducted laboratory bioassays to determine the toxicity of two systemic insecticides, azadirachtin and imidacloprid, for potential control of A. glabripennis and the cottonwood borer, Plectrodera scalator (F.) (Coleoptera: Cerambycidae), a closely related native cerambycid. Larvae of both cerambycid species were fed artificial diet with dilutions of azadirachtin or imidacloprid for 14 wk. Both insecticides exhibited strong antifeedant effects and some toxicity against A. glabripennis and P. scalator larvae. For A. glabripennis, the highest larval mortality at the end of the bioassay was 60% for larvae fed artificial diet treated with azadirachtin (50 ppm) or imidacloprid (1.6 ppm). For P. scalator, the highest larval mortality at the end of the bioassay was 100% for larvae fed artificial diet treated with azadirachtin (50 ppm) or imidacloprid (160 ppm). At 14 wk, the LC50 values for P. scalator were 1.58 and 1.78 ppm for azadirachtin and imidacloprid, respectively. Larvae of both species gained weight when fed diet treated with formulation blanks (inert ingredients) or the water control but lost weight when fed diet treated with increasing concentrations of either azadirachtin or imidacloprid. In a separate experiment, A. glabripennis adults were fed maple twigs treated with high and low concentrations of imidacloprid. A. glabripennis adult mortality reached 100% after 13 d on twigs treated with 150 ppm imidacloprid and after 20 d on twigs treated with 15 ppm imidacloprid. There was no visible feeding by A. glabripennis adults on twigs treated at the higher imidacloprid rate, and feeding was significantly reduced for adults placed on twigs treated at the low imidacloprid rate compared with adults on untreated twigs. In summary, imidacloprid and azadirachtin had both antifeedant and toxic effects against A. glabripennis and P. scalator and have potential for use in management programs. Based on our results, the delivery of high and sustained insecticide concentrations will be needed to overcome the antifeedant effects and lengthy lethal time for both larvae and adults exposed to these insecticides.     

Phytosanitary measures to reduce the movement of forest pests with the international trade of wood products

International trade in wood products brings the risk of the movement of tree pests, which can cause devastating ecosystem and economic damage. International phytosanitary guidelines have been created to help countries that import wood products develop import requirements to minimize pest movement. Requirements may include specific phytosanitary measures, including treatments such as heat, fumigation, chemical, or systems approaches that combine phytosanitary measures. This paper provides an overview of phytosanitary measures for the international trade of wood commodities and the regulatory framework in which they are applied.     

Assessment of the risk of introduction of Anoplophora glabripennis (Coleoptera: Cerambycidae) in municipal solid waste from the quarantine area of New York City to landfills outside of the quarantine area: a pathway analysis of the risk of spread and establishment

The risk associated with spread of Asian longhorned beetle, Anoplophora glabripennis (Motschulsky), from infested areas in New York City to the wide array of landfills across the eastern United States contracted by the city since 1997 was unknown, but of great concern. Landfills, some as far as South Carolina, Virginia, and Ohio, occupied forest types and climates at high risk of Asian longhorned beetle establishment. The city proposed a separate waste wood collection known as the "311 System;" this was estimated to cost federal and state agencies $6.1 to $9.1 million per year, including the cost of processing and disposal of the wood. Pathway analysis was used to quantify the probability that Asian longhorned beetle present in wood waste collected at curbside would survive transport, compaction, and burial to form a mated pair. The study found that in seven alternate management scenarios, risks with most pathways are very low, especially given existing mitigations. Mitigations included chemical control, removal of infested trees, and burial of wood waste in managed landfills that involved multiple-layering, compaction, and capping of dumped waste with a 15-cm soil cover at the end of each day. Although the risk of business-as-usual collection and disposal practices was virtually nil, any changes of policy or practice such as illegal dumping or disposal at a single landfill increased the risk many thousandfold. By rigorously maintaining and monitoring existing mitigations, it was estimated that taxpayers would save $75 to $122 million dollars over the next decade.     

Effects of methyl bromide concentration, fumigation time, and fumigation temperature on Mediterranean and oriental fruit fly (Diptera: Tephritidae) egg and larval survival

The effects of methyl bromide (MB) concentration (16, 32,48, or 64 g/m3), fumigation temperature (15, 20, 25, or 30 degrees C), and fumigation time interactions on the survival of Mediterranean fruit fly, Ceratitis capitata (Wiedemann), and oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), eggs and first and third instars were recorded. Increasing the fumigation temperature from 15 to 20 degrees C or from 20 to 25 degrees C resulted in a significant reduction in fumigation time required for equivalent egg and larval mortalities at all studied MB concentrations; no further reductions in fumigation time resulted from increasing the temperature from 25 to 30 degrees C. Conversely, increasing temperature and time allowed for a reduction in MB concentration to obtain equivalent mortality. Thus, the optimum fumigation temperature for Mediterranean and oriental fruit fly eggs and larvae was 25 degrees C. Reducing MB concentrations required for phytosanitary fumigations would save time and expense, and reduce the amount of MB released into the atmosphere during aeration. Mediterranean fruit fly was as or more tolerant to MB than oriental fruit fly in MB tolerance for eggs and first instars. The egg stage was generally more tolerant to MB regardless of concentration. However, Mediterranean fruit fly eggs showed similar tolerance to first instars at 25 degrees C for the three highest concentrations and to third instars at 25 and 30 degrees C for the highest concentration, with no significant difference between them. Therefore, eggs alone can be used to obtain MB fumigation efficacy and quarantine security data at fumigation temperatures between 15 and 30 degrees C for Mediterranean and oriental fruit fly.     

Use of wood energy in the United States — An opportunity

The use of wood for energy — including the burning of solid wood and black liquor from pulping — has been growing at a rate significantly greater than that for all other uses such as lumber, pulp, or particleboard. In the United States, the end of most wood is not lumber or pulp and paper but feed for energy. In 1983, 155·5 M Mg of wood were used for energy. This could threaten to increase the price of wood for those other uses, or it can stimulate us to seek more creative ways of using untapped wood resources for fuel.On the basis of estimates of heavy wood energy use relative to other uses for wood, and estimates of continuing high costs for fossil fuels, we suggest here the feasibility of meeting the demand for fuelwood through small-scale cooperatives. Such an approach can improve forestry practices and can avoid unduly increasing the cost of wood for other end uses.     

Anaerobic Soil Disinfestation (ASD) Combined with Soil Solarization as a Methyl Bromide Alternative: Vegetable Crop Performance and Soil Nutrient Dynamics

Background and Aims

Soil treatment by anaerobic soil disinfestation (ASD) combined with soil solarization can effectively control soilborne plant pathogens and plant-parasitic nematodes in specialty crop production systems. At the same time, research is limited on the impact of soil treatment by ASD?+?solarization on soil fertility, crop performance and plant nutrition. Our objectives were to evaluate the response of 1) soil nutrients and 2) vegetable crop performance to ASD?+?solarization with differing levels of irrigation, molasses amendment, and partially-composted poultry litter amendment (CPL) compared to an untreated control and a methyl bromide (MeBr)?+?chloropicrin-fumigated control.

Methods

A 2-year field study was established in 2008 at the USDA-ARS U.S. Horticultural Research Lab in Fort Pierce, Florida, USA to determine the effectiveness of ASD as an alternative to MeBr fumigation for a bell pepper (Capsicum annum L.)-eggplant (Solanum melongena L.) double crop system. A complete factorial combination of treatments in a split-split plot was established to evaluate three levels of initial irrigation [10, 5, or 0 cm], two levels of CPL (amended or unamended), and two levels of molasses (amended or unamended) in combination with solarization. Untreated and MeBr controls were established for comparison to ASD treatments.

Conclusions

Results suggest that ASD treatment using molasses as the carbon source paired with solarization can be an effective strategy to maintain crop yields in the absence of soil fumigants. For both bell pepper and eggplant crops, ASD treatments with molasses as the carbon source had equivalent or greater marketable yields than the MeBr control. The application of organic amendments in ASD treatment (molasses or molasses?+?CPL) caused differences in soil nutrients and plant nutrition compared to the MeBr control that must be effectively managed in order to implement ASD on a commercial scale as a MeBr replacement.     

Wood penetration ability of hydrogen cyanide and its efficacy for fumigation of Anoplophora glabripennis,Hylotrupes bajulus (Coleoptera), and Bursaphelenchus xylophilus (Nematoda)

Pinewood nematodes (Bursaphelenchus xylophilus) and Asian longhorned beetles (Anoplophora glabripennis) are the primary regulated pests for packaging wood and timber in the EU, while the house longhorned beetle (Hylotrupes bajulus) is the most important cosmopolitan pest of construction wood. Gaseous hydrogen cyanide (HCN) is one of the few fumigation alternatives to the banned ozone-depleting chemical methyl bromide (MBr). This study reports the results of HCN fumigation experiments in a hermetically sealed steel chamber regarding (1) the penetration and absorption rates of HCN in wooden blocks, and (2) the biological efficacy of HCN against the wood-infesting pests B. xylophilus (in sawdust), A. glabripennis, and H. bajulus (in wooden blocks). A concentration equilibrium for HCN (at 20 g m⁻³) between the fumigation chamber headspace and the center of the treated spruce blocks (100 × 100 × 120 mm) was reached after 48 h in the saturated atmosphere. A dose of 10 g m⁻³ in the center of the spruce blocks was reached for both saturated and non-saturated atmospheres after 24 h of fumigation. The wood tested absorbed approximately 40–45% of the HCN, until equilibrium was reached. The highest tested HCN dose (20 g m⁻³) led to 100% mortality of the A. glabripennis and H. bajulus larvae after less than 1 h of exposure. For 20 g m⁻³ and 1 h exposure the Ct product was <18.66 g*h/m³ for H. bajulus and <17.67 g*h/m³ for A. glabripennis. Hydrogen cyanide doses of 10 g m⁻³ and 20 g m⁻³ led to 100% B. xylophilus mortality in 40 and 18 h, respectively. For B. xylophilus the Ct product was <424.00 g*h/m³ for 20 °C and 10 g m⁻³ and <349.51 g*h/m³ for 25 °C and 20 g m⁻³. The initial results are promising in terms of establishing an alternative technology and protocol to MBr for timber fumigation.