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Journal of Applied Phycology 2018The withdrawal of soil fumigants like methyl bromide is forcing strawberry growers to consider supplementary and alternative ways of producing crops. In addition to...
The withdrawal of soil fumigants like methyl bromide is forcing strawberry growers to consider supplementary and alternative ways of producing crops. In addition to controlling soil-borne pests, soil fumigation causes an increased growth response in strawberry roots, and the use of biostimulants may offer an alternative to replace this response. We tested the hypothesis that treatment with a commercial extract (Seasol®) from the seaweeds and can increase root growth, and transplant (runner) and fruit yields of strawberry. From 2014 to 2016, we conducted three field trials on strawberry farms in the nursery sector at Toolangi and in the fruiting sector at Coldstream in Victoria, Australia. We applied the seaweed extract as a monthly drench (10 L ha) to two cultivars of strawberry ('Albion' and 'Fortuna'), compared with an untreated control. In the nursery sector, use of the extract significantly increased the density of secondary roots (feeder roots) on harvested runners by up to 22%. Treatment with the extract also significantly increased yields of marketable runners by 8-19%. In the fruit sector, use of the extract significantly increased the root length density (root length per volume of soil) of strawberry plants by 38% and marketable fruit yields by 8%. Root length density at final harvest and marketable fruit yield of strawberry were highly correlated ( = 0.94). This relationship provides an insight into the mode of action of seaweed extracts and is discussed. Overall, the results show the potential benefits of the integrated use of seaweed extracts in strawberry production across the nursery and fruit sectors, and their promise for supplementing or replacing the increased growth response provided by soil fumigants.
PubMed: 30416260
DOI: 10.1007/s10811-017-1387-9 -
RSC Advances Jun 2018Inorganic bromide (Br) is an important contaminant ion as it can originate from the overuse of illegal methyl bromide as a fumigant in stored rice samples. Herein, we...
Inorganic bromide (Br) is an important contaminant ion as it can originate from the overuse of illegal methyl bromide as a fumigant in stored rice samples. Herein, we developed a simple and highly sensitive colorimetric sensor for bromide ion detection in rice samples. The sensor is based on the anti-aggregation of gold nanoparticles (AuNPs) by Br in the presence of Cr, which made the method more selective than other typical aggregations of nanoparticles. The AuNPs underwent an aggregation process as a result of the coordination of Cr and the carboxylate group of a citrate ion stabilized the AuNPs, resulting in a red-to-blue color change. When Br was pre-mixed with the AuNPs and Cr was added, the solution color changed from blue to red with an increase in the Br concentration. The anti-aggregation process can be detected with the naked eye and monitored using UV-vis spectrophotometry. The linear calibration curve ranged between 0.31 and 3.75 μM Br with a low LOD and LOQ of 0.04 and 0.13 μM. The recovery was excellent, ranging from 79.9-92.2% with an RSD of less than 4.0%. The good inter-day and intra-day precisions were 2.9-6.4% and 3.1-7.1%, respectively. The developed sensor has proved to provide a robust method for Br detection in rice samples.
PubMed: 35539899
DOI: 10.1039/c8ra03497d -
Journal of Economic Entomology Aug 2018Coffee berry borer (CBB), Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae: Scolytinae), is the most serious insect pest of coffee worldwide. Green coffee used...
Irradiation for Quarantine Control of Coffee Berry Borer, Hypothenemus hampei (Coleoptera: Curculionidae: Scolytinae) in Coffee and a Proposed Generic Dose for Snout Beetles (Coleoptera: Curculionoidea).
Coffee berry borer (CBB), Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae: Scolytinae), is the most serious insect pest of coffee worldwide. Green coffee used in blending and roasting is traded between countries and may be subjected to fumigation for disinfestation of CBB. For example, green coffee shipped to Hawaii from the U.S. mainland must be treated with methyl bromide. Irradiation is an alternative disinfestation treatment option. Dose-response tests were conducted with adult beetles to identify a sterilizing dose, followed by large-scale confirmatory tests with adults infesting coffee berries at 100 Gy (measured doses 84-102 Gy). In total, 6,598 adult CBBs naturally infesting dried coffee berries were irradiated at 100 Gy and produced no viable offspring, whereas 1,033 unirradiated controls produced 327 eggs, 411 larvae, and 58 pupae at 3 wk post treatment. This is the first study to develop a postharvest irradiation treatment for a scolytine bark beetle and supports other studies suggesting 150 Gy is sufficient to prevent reproduction in snout beetles in the superfamily Curculionoidea.
Topics: Animals; Coffea; Coffee; Coleoptera; Hawaii; Quarantine; Weevils
PubMed: 29741635
DOI: 10.1093/jee/toy123 -
Environmental Research Jul 2018To examine the relationship between residential proximity to agricultural fumigant use and respiratory symptoms and lung function in 7-year old children.
OBJECTIVES
To examine the relationship between residential proximity to agricultural fumigant use and respiratory symptoms and lung function in 7-year old children.
METHODS
Participants were 294 children living in the agricultural Salinas Valley, California and enrolled in the Center for the Health Assessment of Mothers and Children Of Salinas (CHAMACOS) study. We obtained information on respiratory symptoms and asthma medication use from maternal questionnaires and children performed spirometry to determine the forced expiratory volume in one second (FEV), forced vital capacity (FVC), and forced expiratory flow 25-75% (FEF) at 7-years of age. We estimated agricultural fumigant use within 3, 5 and 8 km of residences during pregnancy and from birth to age 7 using California's Pesticide Use Report data. We evaluated the association between prenatal and postnatal residential proximity to agricultural use of methyl bromide, chloropicrin, metam sodium and 1,3-dichloropropene with respiratory symptoms and use of asthma medication with logistic regression models and continuous lung function measurements with linear regression models adjusted for confounders.
RESULTS
There were no significant associations between residential proximity to use of fumigants and respiratory symptoms or use of asthma medication. We did not observe any adverse relationships between residential proximity to fumigant use and lung function measurements. Unexpectedly, we observed suggestive evidence of improved FEV and FEF with higher use of methyl bromide and chloropicrin during the prenatal period. For example, for each 10-fold increase in methyl bromide use during the prenatal development period we observed higher FEV (β = 0.06 L/s; 95% CI: 0.00, 0.12) and higher FEF (β = 0.15 L/s; 95% CI: 0.03, 0.27). Maternal report of child allergies (runny nose without a cold during the previous year) modified the relationship between FEV and prenatal proximity to methyl bromide use (p = .07) and we only observed higher FEV among children without allergies (β = 0.08 L/s; 95% CI: 0.02, 0.14 for a 10-fold increase in methyl bromide use during the prenatal period).
CONCLUSIONS
Residential proximity to agricultural fumigant use during pregnancy and childhood did not adversely affect respiratory health in the children through 7 years of age. These findings should be explored in larger studies.
Topics: Agriculture; California; Child; Female; Forced Expiratory Volume; Humans; Male; Pesticides; Pregnancy; Vital Capacity
PubMed: 29482188
DOI: 10.1016/j.envres.2018.02.022 -
Journal of Visualized Experiments : JoVE Nov 2017Nitric oxide (NO) is a newly discovered fumigant for postharvest pest control. This paper provides detailed protocols for conducting NO fumigation on fresh products and...
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.
Topics: Fruit; Fumigation; Insect Control; Nitric Oxide; Vegetables
PubMed: 29286372
DOI: 10.3791/56309 -
Journal of the Royal Society, Interface Dec 2017Concentrations of trace gases trapped in ice are considered to develop uniquely from direct snow/atmosphere interactions at the time of contact. This assumption relies...
Concentrations of trace gases trapped in ice are considered to develop uniquely from direct snow/atmosphere interactions at the time of contact. This assumption relies upon limited or no biological, chemical or physical transformations occurring during transition from snow to firn to ice; a process that can take decades to complete. Here, we present the first evidence of environmental alteration due to microbial metabolism of trace gases (methyl halides and dimethyl sulfide) in polar snow. We collected evidence for ongoing microbial metabolism from an Arctic and an Antarctic location during different years. Methyl iodide production in the snowpack decreased significantly after exposure to enhanced UV radiation. Our results also show large variations in the production and consumption of other methyl halides, including methyl bromide and methyl chloride, used in climate interpretations. These results suggest that this long-neglected microbial activity could constitute a potential source of error in climate history interpretations, by introducing a so far unappreciated source of bias in the quantification of atmospheric-derived trace gases trapped within the polar ice caps.
Topics: Antarctic Regions; Arctic Regions; Atmosphere; Bacteria; Hydrocarbons, Brominated; Hydrocarbons, Iodinated; Ice Cover; Methyl Chloride; Snow; Sulfides
PubMed: 29263129
DOI: 10.1098/rsif.2017.0729 -
PloS One 2017The combination of 1,3-dichloropropene (1,3-D) and metam sodium (MNa) is a potential resource to replace methyl bromide (MB) as a soil fumigant. The efficacy of...
The combination of 1,3-dichloropropene (1,3-D) and metam sodium (MNa) is a potential resource to replace methyl bromide (MB) as a soil fumigant. The efficacy of 1,3-D+MNa as a crucial factor to limit soil-borne pests was evaluated in one laboratory experiment and two cucumber greenhouse studies conducted in commercial operations. Laboratory results revealed that 1,3-D and MNa (10+20 mg a.i. kg-1 soil) provided the best complementary control of the root-knot nematode, Fusarium oxysporum and two species of weed seeds. Greenhouse trials revealed that the blend of 1,3-D and MNa (10+20 g a.i. m-2) greatly inhibited the ability of Meloidogyne incognita to form root galls. In addition, the number of colony-forming units of F. oxysporum declined substantially after growth on media, resulting in higher fruit yields and greater economic benefits. The combined use of 1,3-D and MNa exhibited a higher control efficacy than when 1,3-D or MNa was utilized alone. The ability of this chemical combination to control soil-borne organisms did not differ significantly from the MB treatment and maintained high cucumber yields, enhancing the income of the farmers. Compared to the untreated control group, all the chemical treatments prominently improved the control of the pests. These results show that applying a combination of 1,3-D and MNa provides a promising alternative to MB that enables the sustained growth of cucumber production in China.
Topics: Allyl Compounds; Animals; China; Crops, Agricultural; Cucumis sativus; Fungi; Hydrocarbons, Brominated; Hydrocarbons, Chlorinated; Nematoda; Pesticides; Soil Microbiology; Thiocarbamates
PubMed: 29145472
DOI: 10.1371/journal.pone.0188137 -
PloS One 2017Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) is a serious pest of stored agricultural products and one of the most common insects found in grain storage and...
Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) is a serious pest of stored agricultural products and one of the most common insects found in grain storage and food processing facilities. Heat treatment has been revisited to control stored-product insects as a potential alternative to methyl bromide for disinfesting mills and food-processing facilities. The influence of acclimation of T. castaneum adults, pupae, larvae, and eggs to sublethal temperatures of 36, and 42°C on their subsequent susceptibility to lethal temperature of 50°C was respectively investigated. The acclimation of T. castaneum eggs, larvae, pupae, and adults to 36, and 42°C significantly decreased their subsequent susceptibility to lethal high temperature of 50°C. The influence of acclimation to 42°C was significantly greater than that of acclimation to 36°C. The most influential acclimation times at 42°C for mortality of T. castaneum eggs, larvae, pupae, and adults were 15, 5, 5, and 5 h, respectively, and their corresponding mortality were 41.24, 5.59, 20.19, and 4.48%, compared to 100% mortality of T. castaneum eggs, larvae, pupae, and adults without acclimation when exposed to 50°C for 35 min, respectively. The present results have important implications for developing successful heat treatment protocols to control T. castaneum, improving disinfestation effectiveness of heat treatment and understanding insect response to high temperatures.
Topics: Analysis of Variance; Animals; Gene Expression Regulation; HSP70 Heat-Shock Proteins; Hot Temperature; Insect Proteins; Random Allocation; TRPC Cation Channels; Thermotolerance; Time Factors; Tribolium
PubMed: 28786992
DOI: 10.1371/journal.pone.0182269 -
Journal of Food Protection Sep 2017The purpose of this review is to delineate means of decontaminating soil. This information might be used to mitigate soil-associated risks of foodborne pathogens. The... (Review)
Review
The purpose of this review is to delineate means of decontaminating soil. This information might be used to mitigate soil-associated risks of foodborne pathogens. The majority of the research in the published literature involves inactivation of plant pathogens in soil, i.e., those pathogens harmful to fruit and vegetable production and ornamental plants. Very little has been published regarding the inactivation of foodborne human pathogens in crop soil. Nevertheless, because decontamination techniques for plant pathogens might also be useful methods for eliminating foodborne pathogens, this review also includes inactivation of plant pathogens, with appropriate discussion and comparisons, in the hopes that these methods may one day be validated against foodborne pathogens. Some of the major soil decontamination methods that have been investigated and are covered include chemical decontamination (chemigation), solarization, steaming, biofumigation, bacterial competitive exclusion, torch flaming, microwave treatment, and amendment with biochar. Other innovative means of inactivating foodborne pathogens in soils may be discovered and explored in the future, provided that these techniques are economically feasible in terms of chemicals, equipment, and labor. Food microbiology and food safety researchers should reach out to soil scientists and plant pathologists to create links where they do not currently exist and strengthen relationships where they do exist to take advantage of multidisciplinary skills. In time, agricultural output and the demand for fresh produce will increase. With advances in the sensitivity of pathogen testing and epidemiological tracebacks, the need to mitigate preharvest bacterial contamination of fresh produce will become paramount. Hence, soil decontamination technologies may become more economically feasible and practical in light of increasing the microbial safety of fresh produce.
Topics: Decontamination; Food Contamination; Food Microbiology; Food Safety; Humans; Soil; Soil Microbiology; Vegetables
PubMed: 28782997
DOI: 10.4315/0362-028X.JFP-17-040 -
Occupational and Environmental Medicine Feb 2018Animal studies suggest that exposure to pesticides may alter thyroid function; however, few epidemiologic studies have examined this association. We evaluated the...
OBJECTIVES
Animal 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 679 men enrolled in a substudy of the Agricultural Health Study, a cohort of licensed pesticide applicators.
METHODS
Self-reported lifetime pesticide use was obtained at cohort enrolment (1993-1997). Intensity-weighted lifetime days were computed for 33 pesticides, which adjusts cumulative days of pesticide use for factors that modify exposure (eg, use of personal protective equipment). Thyroid-stimulating hormone (TSH), thyroxine (T4), triiodothyronine (T3) and antithyroid peroxidase (anti-TPO) autoantibodies were measured in serum collected in 2010-2013. We used multivariate logistic regression to estimate ORs and 95% CIs for subclinical hypothyroidism (TSH >4.5 mIU/L) compared with normal TSH (0.4-4.5 mIU/L) and for anti-TPO positivity. We also examined pesticide associations with TSH, T4 and T3 in multivariate linear regression models.
RESULTS
Higher exposure to the insecticide aldrin (third and fourth quartiles of intensity-weighted days vs no exposure) was positively associated with subclinical hypothyroidism (OR=4.15, 95% CI 1.56 to 11.01, OR=4.76, 95% CI 1.53 to 14.82, p <0.01), higher TSH (p=0.01) and lower T4 (p=0.04). Higher exposure to the herbicide pendimethalin was associated with subclinical hypothyroidism (fourth quartile vs no exposure: OR=2.78, 95% CI 1.30 to 5.95, p=0.02), higher TSH (p=0.04) and anti-TPO positivity (p=0.01). The fumigant methyl bromide was inversely associated with TSH (p=0.02) and positively associated with T4 (p=0.01).
CONCLUSIONS
Our results suggest that long-term exposure to aldrin, pendimethalin and methyl bromide may alter thyroid function among male pesticide applicators.
Topics: Aged; Aged, 80 and over; Agricultural Workers' Diseases; Autoantibodies; Humans; Hypothyroidism; Iowa; Logistic Models; Male; Middle Aged; North Carolina; Occupational Exposure; Pesticides; Prevalence; Thyrotropin; Thyroxine; Triiodothyronine
PubMed: 28775130
DOI: 10.1136/oemed-2017-104431