Movement and degradation of mancozeb fungicide and its metabolites, ethylenethiourea and ethyleneurea in silty clay loam soil

Calumpang, S. M. F.; Medina, M. J. B.; Roxas, N. P.; Magallona, E.D.

doi:10.1080/09670879309371783

Cited by 14 publications

(12 citation statements)

References 12 publications

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“…On vegetation, mancozeb's half life is 10 days (Kumar & Agarwal 1992). In soil, it remains in the top 2.5 cm (Calumpang et al . 1993) and breaks down with a half life of 4 days or less (Doneche et al .…”

Section: Pesticide Selectionmentioning

confidence: 99%

“…1993) and breaks down with a half life of 4 days or less (Doneche et al . 1983; Calumpang et al . 1993).…”

Section: Pesticide Selectionmentioning

confidence: 99%

“…1983; Rajagopal et al . 1984), and its breakdown products are undetectable after 2–6 weeks in soil (Calumpang et al . 1993).…”

Section: Pesticide Selectionmentioning

confidence: 99%

“…On vegetation, mancozeb's half life is 10 days (Kumar & Agarwal 1992). In soil, it remains in the top 2.5 cm (Calumpang et al 1993) and breaks down with a half life of 4 days or less (Doneche et al 1983;Calumpang et al 1993). Mancozeb is broken down primarily through abiotic processes such as photooxidation (Doneche et al 1983;Rajagopal et al 1984), and its breakdown products are undetectable after 2-6 weeks in soil (Calumpang et al 1993).…”

Section: Pesticide Selectionmentioning

confidence: 99%

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Trophic control of grassland production and biomass by pathogens

2003

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Current theories of trophic regulation of ecosystem net primary production and plant biomass incorporate herbivores, but not plant pathogens. Obstacles to the incorporation of pathogens include a lack of data on pathogen effects on primary production, especially outside agricultural and forest ecosystems, and an apparent inability to quantify pathogen biomass. Here, I report the results of an experiment factorially excluding foliar fungal pathogens and insect herbivores from an intact grassland ecosystem. At peak in control plots, 8.9% of community leaf area was infected by pathogens. Disease reduction treatment dramatically increased root production and biomass by increasing leaf longevity and photosynthetic capacity. In contrast, herbivory reduction had no detectable effects at the ecosystem or leaf scale. Additionally, biomass of foliar fungal pathogens in the ecosystem was comparable with that of insect herbivores. These results identify pathogens as potential regulators of ecosystem processes and promote the incorporation of pathogens into trophic theory.

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Section: Pesticide Selectionmentioning

confidence: 99%

“…1993) and breaks down with a half life of 4 days or less (Doneche et al . 1983; Calumpang et al . 1993).…”

Section: Pesticide Selectionmentioning

confidence: 99%

“…1983; Rajagopal et al . 1984), and its breakdown products are undetectable after 2–6 weeks in soil (Calumpang et al . 1993).…”

Section: Pesticide Selectionmentioning

confidence: 99%

Section: Pesticide Selectionmentioning

confidence: 99%

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Trophic control of grassland production and biomass by pathogens

2003

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“…Low soil temperatures, anaerobic conditions and/or absence of microorganisms will result in a substantial reduction in the degradation rate of ETU. Although some ETU degradation studies have been reported [2–5], the kinetics of microbial degradation have not been studied in detail.…”

Section: Introductionmentioning

confidence: 99%

Degradation of ethylenethiourea (ETU) in oxic and anoxic sandy aquifers

Jacobsen

Bossi²

1997

FEMS Microbiol Rev

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Ethylenethiourea is an important degradation product of ethylenebisdithiocarbamate fungicides, which are widely used in different kinds of crops. The ethylenebisdithiocarbamate group includes maneb, zineb and mancozeb. The ethylenebisdithiocarbamates are not highly toxic and degrade rapidly in the presence of moisture and oxygen, forming different compounds. One of these is the polar ethylenethiourea, which is relatively stable. Thus, this compound appears to be a potential contaminant for groundwater. Batch experiments were carried out under biotic as well as abiotic conditions to study the degradation dependence of concentration, temperature and organic matter. The decomposition of ethylenethiourea under abiotic conditions was found to be less than 5% of the degradation under biotic conditions. Further, ethylenethiourea showed to be stable over a period of 150 days at 20 degrees C in tap water as well as in batch with soil sterilized with NaN3. The degradation of ethylenethiourea depends on the concentration in the water implying first order reaction kinetics. The microbial degradation of ethylenethiourea is highly temperature dependent with aerobic Q10 between 2.9 and 4.2, and an anaerobic between 2.1 and 2.5. A minor increase in degradation rates was observed by application of nitrate and manure to the batches. The experiments show extremely complete degradation of ethylenethiourea in the presence of microbial nitrate reduction with pyrite which occurs in deeper parts of the aquifers.

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Pollutants in drainage channels following long‐term application of Mancozeb to banana plantations in southeastern Mexico

Melgar

Geissen

Cram

et al. 2008

Z. Pflanzenernähr. Bodenk.

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The aim of this study was to investigate how long‐term Mancozeb application to banana plantations affects the occurrence of pollutants in drainage‐channel sediment and water under tropical conditions. We estimated the possible accumulation of Mancozeb's principal metabolite ethylenethiourea (ETU), as well as manganese (Mn) and zinc (Zn) as components in channel sediment and water. We took samples during the tropical‐rainfall season and the low‐rainfall season. For sediment samples, we determined the contents of ETU, Mn, and Zn. For water samples, we determined the concentration of ETU. Additionally, we took water samples from a runnel that is the receiving body of hydraulic flow from the system. In both seasons, ETU in the sediment was near the detection limit (0.01 mg kg–1) and did not show any accumulation. However, Mn in sediment at all sampling sites exceeded the threshold values for aquatic life of 630 mg kg–1 with values between 635 and 7256 mg kg–1. The Zn concentrations in sediment varied from 87 to 190 mg kg–1 and exceeded the threshold values for aquatic life of 98 mg kg–1 at several sites. Furthermore, we determined an accumulation of these heavy metals in the sediments of the banana‐planted zone in comparison with sediments in pasture reference sites. In contrast to the low concentration of ETU in sediment, its concentration in drainage and runnel water (5.9–13.8 μg L–1) exceeded the EU threshold value for drinking water (0.1 μg L–1) by up to nearly 140 times. However, the threshold value for aquatic life was not exceeded. We conclude that long‐term Mancozeb application does lead to a severe accumulation of Mn in sediments and of ETU in surface water. New strategies should be used to control black Sigatoka, including integrated methods of pest control so that long‐term negative effects on the environment can be avoided.

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Movement and degradation of mancozeb fungicide and its metabolites, ethylenethiourea and ethyleneurea in silty clay loam soil

Cited by 14 publications

References 12 publications

Trophic control of grassland production and biomass by pathogens

Trophic control of grassland production and biomass by pathogens

Degradation of ethylenethiourea (ETU) in oxic and anoxic sandy aquifers

Pollutants in drainage channels following long‐term application of Mancozeb to banana plantations in southeastern Mexico

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