Degradation and Mobility of Pesticides in Norwegian Soils

In this report the following topic of pesticides and fate in Norway has been outlined covering: 1. Factors influencing degradation of pesticides. 2. Description and update of datasets on soil and climate in agricultural areas. 3. Normalization of field degradation data as input for modelling fate. 4. Use of degradation data from Norway in model scenarios. Norwegian laboratory degradation studies indicate that increased soil organic carbon content enhances degradation rates of pesticides that show low sorption (e.g. metalaxyl, bentazone) ,due to increased microbial activity. Whereas pesticides that sorb moderately to strongly to soil (e.g. boscalid, propiconazole), display reduced degradation as organic carbon increases as a consequence of sorption and reduced bioavailability. Recent DegT50 field studies display a large variation in fungicide degradation rates from Klepp in the south to Tromsø in the north. For the mobile herbicide bentazone, no effect of climate was observed, as degradation rates were coherent at all sites, probably due to rapid leaching. The climate (temperature) seems to be more determinate for fungicide degradation rates than the soil type. Fungicide degradation was slow at two northern sites having low soil temperatures, even though microbial biomass was hugely different at the sites. How soil temperature and moisture affects microbial activity and diversity in various soils, climates and crops is important for the understanding of degradation capacity in Norwegian soils and fields. Microbial activity could be related to both soil, climate and crops/cropping regime – as well as to the nature of the soil organic matter. The fact that DegT50 values are very much shorter than laboratory values at the same reference conditions, may point to some systematic error in the normalization procedure (e.g. the default simplifications in the Walker and Arrhenius equations), or that the parameters affecting degradation in the laboratory are different from the parameters that affect degradation in the field. Consequently, lab-derived and field-derived DegT50matrix values should be compared and interpreted with care. The large variations in normalized DegT50 values obtained in field studies in Norway as well as in other regions in Norway cannot be explained by differences in the associated parameters characterizing the soil and microbial community. It is therefore not possible to determine if a certain field study is more or less representative for “Norwegian conditions”. As a conservative approach, the highest, normalized DegT50 from the European field studies should be selected for the Norwegian risk assessment independent on geographic vicinity. As an alternative, when a sufficient number of data are available, a high percentile (e.g 80 or 90-percentile) should be used rather than the geomean. Each agricultural region in Norway is dominated by one specific soil type for each region. Albeluvisol, Cambisol, Umbrisol, Stagnosol and Histosol in respectively Eastern Norway south, Eastern Norway north, Rogaland, Trøndelag and North of Norway. New updates for Norway include especially Umbrisols and Histosols rich in organic matter. Albeluvisols, Cambisols and Stagnosols are representing the main soil types in the agricultural area in Norway. These are also included in the groundwater (Rustad and Heia) and surface water scenarios (Syverud) developed for Norway. Experience from pesticide fate in the organic rich soils on the south west coast and north of Norway is limited. Compared to the “normal” temperature and precipitation from 1961 to 1990 with a “new normal” from 1991 to 2014, the climate has changed. For the five described agricultural areas in Norway, annual temperature has increased in average 1 degrees for all five regions and seasons for the new normal. The rainfall has increased for all seasons and regions except for the Northern Norway (Holt in Tromsø) and summer season at Kvithamar (Trøndelag) with lower precipitation in June to September. Annually the precipitation has increased approximately 100 mm in average. The existing Norwegian scenarios in groundwater and surface water seem to be representative in the meaning of covering the main soil types in the central agricultural areas in South Eastern Norway. However there are no scenarios covering areas of South West and North of Norway containing soil with high organic content, slow degradation and heavy rainfall. Vulnerable areas are not included in these scenarios as the idea of the representativity of soil was to include the main soil types covering the most of the agricultural production areas. The vulnerable areas deals with smaller areas and has to be treated separately. Vulnerable areas are areas with high groundwater levels and sandy soil and mobile pesticides. Hilly areas with clay soil represent high risk of surface runoff with strongly sorbed pesticides. We are lacking experience from areas with high content of organic matter causing slow degradation, combined with heavy rainfall. A database with representative soils and climates for various crops should be established in Norway and utilized in a targeted risk assessment approach. Then, the degradation of pesticides to be used in for example fruit/berry cropping, could be evaluated in respect to representative and vulnerable soils and climates in fruit/berry regions in Norway. A correct risk assessment of pesticide degradation in Norwegian agricultural soils should take the varying climatic zones, the diversity in agricultural soils and crops in Norway into consideration before formulated pesticides are approved. Risk assessment should be based on soils and climates most prevalent for the crop to which the pesticide is to be applied, in addition, vulnerable areas with slow degradation and/or high leaching/runoff risk should be recognized.

Effectiveness of carboxylic acids from Pichia membranifaciens against coffee rust / Eficácia do ácido carboxílico de Pichia membranifaciens contra a ferrugem do cafeeiro

ABSTRACT Coffee rust is a fungal disease that has affected every coffee-producing region in the world. Given that the effectivity of the protectant and systemic fungicides applied routinely to control the spread of the causative agent of the disease (Hemileia vastatrix) has gradually diminished, besides are harmful to mammals and ecosystems, the objective of this work was to search for a mixture of harmless natural compounds with the potential to be applied in the field. So, a yeast strain producing a battery of long-chain carboxylic acids (CA) with fungicide properties was isolated from soil of coffee crop and identified as Pichia membranifaciens by ITS sequencing. Culture conditions of the yeast were optimized and the CA in the solution were characterized by Gas Chromatography-Mass Spectrometry (GC-MS) as ethyl formate (55.5 g L-1), octadecenoic acid (3.5 g L-1), propionic acid (7.2 g L-1), 3-(octadecanoyl)-propionic acid (7.2 g L-1) and methyl acetate (8.4 g L-1). Randomized field studies were conducted in three different locations in Chiapas, México. Five treatments were tested including three concentrations of the CA solution (389, 584 and 778 ppm) and copper oxychloride (5 000 ppm) as conventional control. The initial coffee rust incidence averages varied between sites: Maravillas (3-9%), Santo Domingo (10-16%) and Búcaro (16-22%). The treatments of CA solution proved to be effective at slowing down the progress of the rust disease even for the sites where initial incidence was high. Likewise, the CA solution reduced the viability of H. vastatrix spores, as assessed by fluorescence microscopy.

RESUMO A ferrugem do cafeeiro é uma doença que tem afetado as regiões produtoras de café no mundo. Considerando que os funguicidas protetores e sistemáticos que são aplicados rotinariamente para controlar a difusão do agente causador da doença (Hemileia vastatrix) são nocivos para os humanos, animais e ecossistemas, o objetivo deste trabalho é determinar um componente natural com potencial de uso. Uma cepa de levedura produzindo uma bateria de ácidos carboxílicos com ação funguicida foi isolada do solo e identificada como Pichia membranifaciens por sequenciamento ITS. Foram optimizadas as condições de cultura e os ácidos carboxílicos presentes na semi purificada sobrenadante (solução CA) foram caracterizados por cromatografia de gás espectometia de massa (GC-MS) como formato de etilo (55.5 g L-1), ácido octadecenóico (3.5 g L-1), ácido propiônico (7.2 g L-1), 3-(octadecanoil)-ácido propiônico 7.2 g L-1) e acetato de metilio (8.4 g L-1). Estudos do campo foram conduzidos em três locais na região de Chiapas, Mexico. Cinco tratamentos foram testados incluindo três concentrações da solução CA (389, 584 e 778 ppm) e o funguicida comercial contendo oxicloreto de cobre (500 ppm). As médias iniciais de incidência da ferrugem do cafeeiro variou em função do local: Maravilla (3-9%), Santo domingo (10-16%) e Búcaro (16-22%). A solução CA provou ser efetiva retardando o progresso da doença, mesmo nos locais onde a incidência inicial foi elevada. A solução CA reduziu a viabilidade dos esporos de H. Vastatrix, observado por meio de fluorescência.

Del laboratorio al campo abierto: El uso de protocolos de adaptación y socialización en Rattus Norvegicus / From the lab to the open field: The use of adaptation and socialization protocols with Rattus Norvegicus

El objetivo de este artículo es presentar un protocolo para la adaptación y socialización de sujetos de investigación Rattus norvegicus, cepa Wistar, como parte de un proyecto que busca el entrenamiento de estos animales para la detección de explosivos, tanto en laboratorio como en campo abierto. Se describe el diseño de las habitaciones de los animales, que son distintas de las jaulas-hogar típicas de los bioterios estándar. A continuación, se relaciona la exposición de los animales a diferentes ambientes físicos. Por último, se examina el protocolo de socialización interespecífica de las ratas tanto con humanos como con animales de otras especies.

The goal of this paper is to introduce an adaptation-and-socialization protocol for animal subjects Rattus norvegicus, Wistar strain, into a research project that aims to train these animals to detect explosives, both in laboratory and open field. We describe the design of the home cages, which are different from the vivarium's standard home cages. Next, the exposure of the animals to different physical environments is related. Finally, the inter-specific socialization protocol of the rats with humans and other animals is described.

Design of field studies on vaccines which involves capturing indirect effect / 中华流行病学杂志

For most variety of vaccines, two types of effects-direct and indirect, can result from immunization programs. Unimmunized individuals in the population that receive immunization program can benefit from the vaccines in addition to the protection from immunization.The classical vaccine trails allocate individuals into study and control arms with individual randomization, so the programs' cost-benefit is underestimated due to the impossible measurement on indirect effect. The objectives of the present work are to introduce the conceptual framework,developed by Halloran et al, for four types of study designs that differentiate and account for direct,indirect, total and overall effects of intervention programs, and to explain the relationships of these effects as well. With the examples of field trails of oral cholera vaccines in Bangladesh and Vi typhoid vaccine in India, further issues refer to the identification of indirect effect. The application in practice is also discussed.