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RETRACTED: Trends in bromide wet deposition concentrations in the contiguous United States, 2001–2016
2018
Wetherbee, Gregory A. | Lehmann, Christopher M.B. | Kerschner, Brian M. | Ludtke, Amy S. | Green, Lee A. | Rhodes, Mark F.
This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal).This article has been retracted at the request of the authors due to the results of a detailed investigation of the data quality conducted by the Central Analytical Laboratory (CAL) after relocation to the University of Wisconsin (UW) – Wisconsin State Laboratory of Hygiene. Using a subset of the 30 samples with the highest bromide ion (Br-) concentrations, the CAL at UW found 6 samples that could not be verified or were incorrect. Because the extent of the incorrect data is unknown, the NADP Executive Committee voted unanimously in May 2019 to discontinue public access to these data, and they decided to sequester all Br- data prior to June 2018. These issues were not obvious to the authors when the paper was written.The authors apologize for the inconvenience caused.
Afficher plus [+] Moins [-]An emerging chemical fumigant: two-sided effects of dazomet on soil microbial environment and plant response
2022
Chen, Ran | Jiang, Weitao | Xu, Shaozhuo | Fan, Hai | Chen, Xuesen | Shen, Xiang | Yin, Chengmiao | Mao, Zhiquan
Methyl bromide has been banned worldwide because it causes damage to the ozone layer and the environment. To find a substitute for methyl bromide, the relationships among fumigation, plant growth, and the microbial community in replant soil require further study. We performed pot and field experiments to investigate the effects of dazomet fumigation on soil properties and plant performance. Changes in soil microbial community structure and diversity were assessed using high-throughput sequencing, and plant physiological performance and soil physicochemical properties were also measured. Dazomet fumigation enhanced photosynthesis and promoted plant growth in replant soil; it altered soil physical and chemical properties and reduced soil enzyme activities, although these parameters gradually recovered over time. After dazomet fumigation, the dominant soil phyla changed, microbial diversity decreased significantly, the relative abundance of biocontrol bacteria such as Mortierella increased, and the relative abundance of pathogenic bacteria such as Fusarium decreased. Over the course of the experiment, the soil microbial flora changed dynamically, and soil enzyme activities and other physical and chemical properties also recovered to a certain extent. This result suggested that the effect of dazomet on soil microorganisms was temporary. However, fumigation also led to an increase in some resistant pathogens, such as Trichosporon, that affect soil function and health. Therefore, it is necessary to consider potential negative impacts of dazomet on the soil environment and to perform active environmental risk management in China.
Afficher plus [+] Moins [-]Study on the Hydrolysis Kinetics of Dimethyl Disulfide
2017
Han, Dawei | Yan, Dongdong | Cao, Aocheng | Fang, Wensheng | Wang, Xianli | Song, Zhaoxin | Li, Yuan | Ouyang, Canbin | Guo, Meixia | Wang, Qiuxia
Dimethyl disulfide (DMDS) is a new soil fumigant that is considered a good alternative to methyl bromide due to its high activity toward soil-borne pests, with no ozone-depleting potential. The correlative literature for the study of DMDS and its environmental fate is limited. The hydrolysis kinetics of DMDS were studied in buffered aqueous solutions within a pH of 5, 7, and 9, temperature at 15, 25, 45, and 65 °C, and in natural water samples at an ambient temperature of 25 °C. The results showed that DMDS hydrolysis rates were accelerated by increases in pH and temperature. The calculated half-lives of DMDS hydrolysis in the solutions of pH 5, 7, and 9 were 13.91, 10.81, and 10.52 days, respectively at 25 °C, and the trend showed that DMDS hydrolyzed faster in neutral or mild alkali conditions than in acidic solutions at the same temperature. The calculated half-lives of DMDS hydrolysis in the solutions at 15, 25, 45, and 65 °C were 15.78, 10.81, 9.78, and 7.72 days at pH = 7, respectively. There existed no obvious correlations between the activation energies of DMDS hydrolysis and temperatures. However, the activation entropy absolute values of DMDS hydrolysis increased with increasing temperatures, suggesting that the hydrolysis of DMDS in aqueous solutions was driven by activation entropy. The hydrolysis rates of DMDS in natural water samples are as follows: rice paddy field water > Grand Canal water > tap water. Sterilization of three kinds of natural water samples showed that biodegradation accounted for 4.08, 21.52, and 8.82% in tap water, paddy field water, and Grand Canal water, respectively. This research result has important implications in the scientific evaluation of DMDS.
Afficher plus [+] Moins [-]Effect of vinegar residue compost amendments on cucumber growth and Fusarium wilt
2015
Du, Nanshan | Shi, Lu | Du, Lantian | Yuan, Yinghui | Li, Bin | Sang, Ting | Sun, Jin | Shu, Sheng | Guo, Shirong
Fusarium wilt of cucumber caused by Fusarium oxysporum f. sp. cucumerinum J. H. Owen is one of the major destructive soilborne diseases and results in considerable yield losses. Methyl bromide was once the most effective disease control method but has been confirmed as harmful to the environment. Using suppressive media as biological controls to assist crop growth is becoming popular. In this study, Fusarium wilt of cucumber was successfully controlled by a newly identified suppressive media: vinegar residue compost-amended media (vinegar residue compost mixed with peat and vermiculite in a 6:3:1 ratio (v/v) vinegar residue substrate (VRS). Greenhouse experiments were carried out to evaluate the effect of VRS on the growth of cucumber seedlings and disease suppression. The control was peat/vermiculite (2:1, v/v). To identify the mixed media most suitable for the growth of plants and their suppressiveness indicators, we evaluated the biological characteristics of cucumber, the physicochemical and biochemical properties of the growth media, and the enzyme activities. Total organic C (Cₒᵣg), microbial biomass C (Cₘᵢc), basal respiration (Rₘᵢc), and enzyme (catalase, invertase, urease, proteinase, phosphatase, β-glucosidase, and hydrolysis of fluorescein diacetate) activities increased significantly after vinegar waste compost amendment. The compost media also showed a significantly positive effect on the growth of cucumber seedlings and the suppression of the disease severity index (DSI, 38 % reduction). The cucumber rhizosphere population of F. oxysporum f. sp. cucumerinum (FOC) was significantly lower in VRS than in the control. These results demonstrate convincingly that vinegar residue compost-amended media has a beneficial effect on cucumber growth and could be applied as a method for biological control of cucumber Fusarium wilt.
Afficher plus [+] Moins [-]Effectiveness of carbon dioxide against different developmental stages of Cadra cautella and Tribolium castaneum
2017
Husain, Mureed | Sukirno, Sukirno | Meman, K̲h̲ālid Maḥmūd | Tufail, Muhammad | Rasool, Khawaja Ghulam | Alwaneen, Waleed Saleh | Aldawood, Abdulrahman Saad
Methyl bromide is an excellent fumigant but has been banned because it has high potential for depleting the ozone layer which leads to many environmental and human health hazard issues. In this connection, effectiveness of carbon dioxide (CO₂, 99.9%) was studied as an alternative to methyl bromide under various exposure timings, 25 ± 1 °C, against different developmental stages of the almond moth, Cadra cautella, and red flour beetle, Tribolium castaneum. In case of C. cautella, the LT₉₉ against adult, pupa, and larval stages was achieved after 37.5, 78.1, and 99.9 h of CO₂ application, respectively. While for T. castaneum, the LT₉₉ values were obtained after exposure timings of 29.3, 153.9, and 78.4 h against adult, pupa, and larval stages, respectively. Adults were very susceptible; in contrast, pupae and larvae were more tolerant. The susceptibility order was observed as follows: T. castaneum adult > C. cautella adult > C. cautella pupae > T. castaneum larvae > C. cautella larvae > T. castaneum pupae. This study could be useful in developing the management strategies to prevent stored dates from C. cautella and T. castaneum infestation.
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