Control of late blight in organic potato production: evaluation of copper-free preparations under field,growth chamber and laboratory conditions

In order to replace copper fungicides in organic potato production, 53 copper-free preparations (CFPs) based on natural compounds, including plant extracts and microorganisms, and five copper preparations were evaluated for their potential to control Phytophthora infestans, the pathogen that causes late blight of potatoes. In in vitro assays, 30% of the CFPs inhibited indirect germination of sporangia, 26% mycelial growth and in growth chamber experiments, 21% efficiently reduced foliar blight of tomato plants. In micro-plot field trials with applications twice a week, the copper preparations were the most effective and reduced foliar blight by 99%. Of the CFPs tested, Oekofluid P, Mycosin and other sulphuric clays, and C-2000 reduced late blight the most, from 63% to 37%. In small-plot trials in 2001, 2002 and 2004, 27 CFPs with different formulations and four copper preparations were examined. In 2004, copper preparations at full and reduced rates and sulphuric clays were applied either weekly or according to the decision support system Bio-PhytoPRE. With Bio-PhytoPRE, copper preparations reduced foliar blight of potatoes by 23–77% and increased tuber yield by 2–28%, depending on the copper rate applied and year. With CFPs, maximal efficacy was 17% and no effect on tuber yield was observed. In vitro and in vivo trials showed that the rainfastness and the persistence of CFPs was low compared with copper preparations. This indicates that the failure of CFPs under field conditions is probably due to a lack of stability under prevailing environmental conditions and not to a lack of efficacy. Until stable formulations for CFPs are developed, an optimised and restricted use of copper fungicides using a decision support system could help to control late blight in organic potato production and to reduce copper input into the environment.     

In vitro determination of the allergenic potential of technologically altered hen's egg

Hen's egg allergy represents one of the most common and severe IgE-mediated reactions to food in infants and young children. It persists, however, in many cases also lifelong. Therefore, the aim of this study was the detailed analysis of a technological process used to reduce the allergenic potential of hen's egg. The investigation focused on the pasteurized egg as starting material, intermediate, and final products of a nine-step manufacturing process performed for use of eggs in convenience products appropriate for allergic individuals. The steps consisted of a combination of various heat treatments and enzymatic hydrolyses. The alterations were controlled by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), immunoblotting, enzyme allergosorbent test (EAST) inhibition, and mass spectrometry. Thereby it could be demonstrated that the allergenic potential of the raw material was reduced from step to step, and despite the known stability against heat and proteolysis of certain egg proteins, the total allergenic potential was finally below 1/100 that of the starting material without a significant change in texture and flavor as evaluated in various products.     

Hemoglobin adducts and mercapturic acid excretion of acrylamide and glycidamide in one study population

The aim of this study was to determine the relationship between the oxidative and reductive metabolic pathways of acrylamide (AA) in the nonsmoking general population. For the first time both the blood protein adducts and the urinary metabolites of AA and glycidamide (GA) were quantified in an especially designed study group with even distribution of age and gender. The hemoglobin adducts N-carbamoylethylvaline (AAVal) and N-( R, S)-2-hydroxy-2-carbamoylethylvaline (GAVal) were detected by GC-MS/MS in all blood samples with median levels of 30 and 34 pmol/g of globin, respectively. Concentrations ranged from 15 to 71 pmol/g of globin for AAVal and from 14 to 66 pmol/g of globin for GAVal. The ratio GAVal/AAVal was 0.4-2.7 (median = 1.1). The urinary metabolites were determined by LC-MS/MS. Of all urine samples examined 99% of N-acetyl- S-(2-carbamoylethyl)- l-cysteine (AAMA) levels and 73% of N-( R/ S)-acetyl- S-(2-carbamoyl-2-hydroxyethyl)- l-cysteine (GAMA) levels were above the LOD (1.5 microg/L). Concentrations ranged from 相似文献   

Consumer preferences for front-of-pack calories labelling

OBJECTIVE: In light of the emerging obesity pandemic, front-of-pack calories labels may be an important tool to assist consumers in making informed healthier food choices. However, there is little prior research to guide key decisions on whether caloric content should be expressed in absolute terms or relative to recommended daily intake, whether it should be expressed in per serving or per 100 g and whether the information should be further brought alive for consumers in terms of what the extra calorie intake implies in relation to activity levels. The present study aimed at providing more insight into consumers' appreciation of front-of-pack labelling of caloric content of food products and their specific preferences for alternative execution formats for such information in Europe. DESIGN: For this purpose, eight executions of front-of-pack calorie flags were designed and their appeal and information value were extensively discussed with consumers through qualitative research in four different countries (Germany, The Netherlands, France and the UK). RESULTS: The results show that calories are well-understood and that participants were generally positive about front-of-pack flags, particularly when flags are uniform across products. The most liked flags are the simpler flags depicting only the number of calories per serving or per 100 g, while more complex flags including references to daily needs or exercise and the flag including a phrase referring to balanced lifestyle were least preferred. Some relevant differences between countries were observed. Although participants seem to be familiar with the notion of calories, they do not seem to fully understand how to apply them. CONCLUSION: From the results, managerial implications for the design and implementation of front-of-pack calorie labelling as well as important directions for future research are discussed.     

Schätzung der mikrobiellen Biomasse von Böden aus anthropogenen und natürlichen Substraten — ein Beitrag zur Standortbewertung

Field estimation of the microbial biomass of soils derived from natural and anthropogenic parent materials Whereas the estimation and evaluation of physical and chemical soil properties is possible with the use of widely accepted methods, there is still no procedure with respect to microbiological parameters. Therefore, our objective was to develop a field procedure for estimating the integral parameter ”︁microbial biomass”. For this purpose, microbial biomass data (C_mic in dry matter) of soils developed in natural parent materials from 116 sites in Germany and abroad were analyzed. Additionally, C_mic in 33 German soils developed in anthropogenic parent materials was determined. In the soils under consideration, C_mic varied between 100 and 4000 kg ha^—1 in the upper 30 cm. For soils of natural substrates statistical relations between C_mic and the humus and clay content as well as pH were derived. From these parameters which are combined as the diagnostic characteristics of humus a simple procedure for estimating C_mic of arable soils was developed. For soils developed in anthropogenic parent materials, however, an estimation procedure was developed that uses the nature of the parent material and the degree of soil development. To evaluate the estimated amount of C_mic, a frame consisting of 6 classes is proposed: < 200 kg ha^—1 (= very low), 200—400 kg ha^—1 (= low), 400—800 kg ha^—1 (= moderate), 800—1600 kg ha^—1 (= medium), 1600—3200 kg ha^—1 (= high), and > 3200 kg ha^—1 (= very high).     

Towards Sustainable Potato Production: Partnering to Support Family Farmers in Africa

This paper highlights the current developments towards the sustainable intensification of crop production to combat hunger and malnutrition. It also stresses the specific role the cultivation of potato can play in abolishing hunger and malnutrition. Finally, it describes the role of the Food and Agriculture Organization of the United Nations in achieving sustainable intensification of potato production.     

Forstmeteorolgische Messungen in einem Eichenbestand

Ohne Zusammenfassung     

Lifespan and mortality of old oaks — combining empirical and modelling approaches to support their management in Southern Sweden

? Old oaks (Quercus robur L.) play an important role in the southern Scandinavian landscape by providing habitat for a wide range of species, a large proportion of them being currently on the National Redlists.

? To provide support for the management of these trees, we review data on oak mortality and formulate a mortality-driven stochastic model analysing interactions between mortality rate, oak recruitment rate into 100–150 age class, and amount of oaks older than 200 years.

? Empirical annual mortality rates varied between 0 and 13% with average 1.68%. Trees older 200 years had an average mortality rate of 1.1%. Oaks in the high density forests showed higher mortality (3.2%) as compared to the trees growing in the low density forests (1.2%). A 400-year long modelling exercises indicated that under current mortality rates (regular mortality being centred around 1% annually; and irregular mortality 7% with average return time of 13 years) the long-term maintenance of 20 trees older than 200 years per ha would require an input rate of 1 to 5 trees × year^?1 × ha^?1 into the 100–150 years old class.

? The modelling highlighted the importance of initial oak abundance affecting amount of old trees at the end of shorter (100 years) simulation period.

     

Sunflower expellers have greater ileal digestibility of amino acids than sunflower meal,but there are only minor variations among different sources of sunflower meal when fed to growing pigs

The objective was to test the hypothesis that there is no effect of origin or processing procedure on the standardized ileal digestibility (SID) of amino acids (AA) and crude protein (CP) in sunflower coproducts. Six sources of sunflower meal (SFM) and one source of sunflower expellers (SFE) were obtained from Ukraine, Italy, Hungary, and the United States. Each source of SFM or SFE was the only source of CP and AA in one diet, and an N-free diet was also used for a total of eight diets. Eight barrows (body weight: 28.5 ± 2.4 kg) had a T-cannula installed in the distal ileum and were allotted to one of the eight diets using an 8 × 8 Latin square design with eight periods. The Lys:CP ratio in the six sources of SFM ranged from 3.10% to 3.96% with CP concentrations ranging from 27.34% to 36.75%. CP in SFE was 26.87% and the Lys:CP ratio was 3.51%. Concentrations of acid-hydrolyzed ether extract in the six sources of SFM ranged from 0.60% to 3.11%, but SFE contained 8.77%. Results indicated that the SID of CP was lower (P < 0.05) in SFM from Hungary compared with all other sources of SFM except for one of the sources from Ukraine. There were no differences in the SID of Lys, Met, and Trp among sources of SFM, but for most of the remaining indispensable AA, the SFM from Hungary had less (P < 0.05) SID than the other sources. However, only a few differences in the SID of indispensable AA were observed among the other sources of SFM, but the SID of CP and all AA except Trp was greater (P < 0.05) in SFE compared with SFM. In conclusion, there were only a few differences in the SID of the first-limiting AA among SFM obtained from Ukraine, Hungary, Italy, and the United States, but the SID of CP and AA was greater in SFE than in SFM indicating that processing of sunflower seeds influence the nutritional value.