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Estimating damage caused by wild animals to crops by comparing yields
Get PDFWachsende Populationen großer Pflanzenfresser haben in den letzten Jahren erhebliche Schäden an Nutzpflanzen verursacht. Verschärft wird die Situation durch das Fehlen verlässlicher Methoden zur Bestimmung des Schadensausmaßes und zur anschließenden Berechnung der Entschädigung für die zerstörten Ernten. In dieser Studie haben wir die Bedingungen und Möglichkeiten für die Anwendung der Methode zur Abschätzung der durch Wildtiere verursachten Schäden definiert, die auf dem Vergleich der Erträge in geschädigten und nicht geschädigten Gebieten basiert. Diese Methode ist ein guter Kompromiss zwischen Zeitaufwand und Genauigkeit der Schadensermittlung. Die vorgeschlagene Methode deckt auch Wettbewerbsprobleme (unbeschädigte Pflanzen mit eliminierter Konkurrenz können einen erhöhten Ertrag haben) und Wachstumskompensation ab (z. B. wenn die Pflanze in einem frühen Wachstumsstadium beschädigt wird), die mit den derzeit verwendeten Methoden nicht objektiv bewertet werden können. Diese Methode ist auch für die Schadensbestimmung einer Vielzahl von landwirtschaftlichen Kulturen geeignet. Sie muss jedoch in Zukunft durch weitere Studien weiterentwickelt werden. Bei der beschriebenen Methode handelt es sich um ein Gedankenexperiment. Sie muss in der Praxis getestet werden, um ihre Genauigkeit und Komplexität mit anderen Methoden zu vergleichen.Growing populations of large herbivores have caused significant damage to crops in recent years. The situation is exacerbated by the lack of reliable methods for determining the extent of the damage and for the subsequent calculation of the compensation for the destroyed crops. In this study, we defined the conditions and options for application of method for estimating damage caused by wild animals, which is based on comparison of yields in damaged and undamaged areas. This method is a good compromise between time consumption and accuracy of the damage determination. The proposed method also covers competition problems (undamaged plants with eliminated competition may have an increased yield) and growth compensation (for example when the plant is damaged at an early stage of growth) that the currently used methods could not objectively evaluate. This method is also suitable for determining the damage of a wide range of agricultural crops. The method described is a thought experiment and needs to be tested in practice to compare its accuracy and complexity with other methods
Habilitationen und Promotionen in den Pflanzenbauwissenschaften: Die Gesellschaft für Pflanzenbauwissenschaften (GPW) teilt mit:
No full textThree-dimensional approach for identification of red grape cultivars by fingerprint of wine anthocyanins
Get PDFThe authenticity of grape cultivars is an important tool for wine controlling systems. The identification of red grape cultivars by wine anthocyanin spectra is a well-known method, but the analysis of applied parameters does not produce exact results. This work aimed at identifying substantive parameters, which, if applied simultaneously, will allow identifying numerous cultivars with high certainty. Liquid chromatography has been applied to obtain anthocyanin profiles of single-cultivar red wines made of various cultivars. Ratios of the peak areas of individual anthocyanins were identified. The proportions of anthocyanins depend on many factors, but their constancy is predetermined genetically. Certain ratios of peak areas of individual anthocyanins can be estimated as constant and typical for concrete cultivars. Revealed combinations of three ratios were estimated as unique for each cultivar. Moreover, different clones of certain cultivars have different combinations of constant ratios. Analysed samples were distributed in groups according to the combination of constancies of three ratios manifested in chromatographic peaks. The three-dimensional model produced allows data distribution in different groups. Each group corresponds to individual cultivars or different clones of one cultivar. Their belonging to concrete groups makes it possible to efficiently identify unknown single-cultivar wines and detect forgery
Frateuria defendens reduces yellows disease symptoms in grapevine under field conditions
Get PDFYellows diseases in grapevine, associated with the presence of different phytoplasmas, are a major problem for growers, with no environmentally friendly means of control. Frateuria defendens (Frd), a bacterium with endophytic traits, has been shown to reduce yellows symptoms in grapevine plantlets under laboratory conditions. The objective of this study was to test whether similar effects could be achieved under field conditions. A trial was conducted in a heavily infected vineyard in northern Israel for two consecutive years. A suspension of Frd cells (108·mL-1) was applied bi-weekly by foliar spray on grapevines from bud burst to leaf senescence. Frd penetrated the leaves during the growing period but not during leaf senescence and could be detected in the leaves by PCR analysis up to 14 days post-spraying. The rate of yellows infection was lower in the treated grapevines compared to its increase in untreated grapevines and the yield of symptomatic plants was improved by 10 to 20 %. Taken together, the results suggest Frd acted as a biological control agent in vineyards under the experimental conditions tested
Acaulospora flava, a new arbuscular mycorrhizal fungus from Coffea arabica and Plukenetia volubilis plantations at the sources of the Amazon river in Peru
Get PDFA new arbuscular mycorrhizal fungus, Acaulospora flava, was found in coffee (Coffea arabica) and inka nut (Plukenetia volubilis) plantations in the Amazonia region of San Martín State in Peru. The fungus was propagated in bait cultures on Sorghum vulgare, Brachiaria brizantha and Medicago sativa as host plants. It differentiates typical acaulosporoid spores laterally on sporiferous saccule necks. The spores are light yellow, bright yellow to yellow brown, (95-)105-160 × (95-)100-150 μm in diameter and have smooth spore surfaces. Phylogenetically, A. flava clusters in a well-separated clade, nearest to A. kentinensis, followed by A. herrerae, A. spinosissima, A. excavata and A. aspera, of which remarkably A. spinosissima, A. excavata and A. aspera had also been found in inka nut plantations of San Martín State during the last years.
Here, we report also A. herrerae and A. fragilissima as fungal symbionts within the rhizosphere of coffee and the inka nut. The later two fungi had so far been recorded by concomitant morphological and molecular analyses only from tropical islands, A. herrerae from Cuba in the Golf of Mexico and A. fragilissima from New Caledonia in the southwest Pacific Ocean close to Australia. In this study, the ITS region of A. herrerae was analyzed for the first time and deposited in the public databases.
In total, we already recovered fourteen Acaulospora species from coffee and inka nut plantations in San Martín State of Peru, suggesting that Acaulospora species are frequent and beneficial symbionts in coffee and inka nut roots in San Martín State of Peru
Spontaneous polyploidisation of interspecific and intersectional Pelargonium hybrids during embryo rescue
Get PDFModern Pelargonium crispum hybrids (section Pelargonium) show low genetic and phenotypic variation due to the domestication effect. Species of the sections Cortusina, Ligularia, and Pelargonium are potential breeding partners at the diploid level (2n = 2x = 22). Five P. × crispum cultivars were used as seed parents and pollinated with one genotype of P. grandiflorum (section Pelargonium) and three genotypes of P. fulgidum (section Ligularia). In both combinations, embryo rescue was necessary. Embryos were rescued and cultured on Murashige & Skoog medium supplemented with phytohormones. After callus and adventitious shoot regeneration 15 viable interspecific hybrids were obtained from crossbreeding with P. grandiflorum and 11 intersectional hybrids from crossings with P. fulgidum, respectively. The hybrids were cultivated in the greenhouse until flowering. Their hybrid character was evident due to the intermediate morphological traits. Molecular investigations using dp-RAPD analysis confirmed this. Within the F1 population P. × crispum with P. grandiflorum three hybrids and after crossing with P. fulgidum one hybrid possessed larger flowers and fully developed anthers, respectively. Their ploidy level was confirmed as tetraploid using flow cytometry. Therefore, a spontaneous polyploidisation occurred during in vitro regeneration. The tetraploid F1 hybrids are fertile and could be used for further breeding
Effect of calcium chloride post-harvest treatment in combination with plant natural substance coating on fruit quality and storability of tomato (Solanum lycopersicum) fruits during cold storage.
Get PDFIn this study, the impact of postharvest treatments with calcium chlo-ride (CaCl2) in-combination with postharvest coating treatments with plant natural substance arabic gum or cactus mucilage on the qua-lity and storage life of tomato fruits during cold storage (10 ± 1 °C, RH 85% ± 3) was evaluated. Results of dipping tomato fruits in 6% CaCl2 for 10 minutes combined with postharvest coating treatments with either 10% Arabic gum or 50% cactus mucilage for 3 minutes showed significant (p<0.05) higher value of fruit firmness, titratable acidity, reduce the percentage of weight loss and percent of decayed fruits. Treated fruits took longer to change color from pink to red compared with non-treated fruits. This study showed that dipping to-mato fruits in 6% CaCl2,orcoating with different natural substances alone or in combination with CaCl2, enhances tomato fruits’ physical and chemical properties. Moreover, preserving tomato fruits can be preserved for a longer time compared with control fruits and main-tain the overall fruit quality
Comparison of two sample preparation methods for 1H-NMR wine profiling: Direct analysis and solid-phase extraction
Get PDFThis study compares two sample preparation methods: direct analysis (DA) and solid-phase extraction (SPE) for wine samples analysis by proton nuclear magnetic resonance (1H-NMR) spectroscopy. For this purpose, the profile of Mexican commercial wines was evaluated. The selected wines were produced with different grape varieties: (\u27Barbera\u27, \u27Nebbiolo\u27, \u27Zinfandel\u27, \u27Merlot\u27, \u27Petite Syrah\u27, \u27Cabernet Sauvignon\u27, \u27White Zinfandel\u27 and mixture of \u27Chenin blanc\u27 and \u27Colombard\u27) coming from the principal wine-producing region of Mexico, Baja California State. DA provided faster data acquisition in comparison to SPE and preserved the original sample composition. Using DA-NMR thirty two metabolites were identified, including organic acids, amino acids, sugars, alcohols and phenolic compounds. Furthermore, SPE-NMR using a polymeric sorbent allowed to retain phenolic compounds giving a better picture on the aromatic region and eliminating major polar compounds like water, ethanol and sugars. Fourteen compounds were identified by SPE-NMR including higher alcohols, flavanols and hydroxybenzoates. A control chart for the first principal component allowed to confirm the precision of the SPE-NMR method, while a comparison of the concentration of two metabolites found in both methods was used to evaluate their recovery (20 % for isoamyl alcohol and 78 % for phenethyl alcohol). The information obtained with both methods about the main compounds and phenolic metabolites provides new insights into the metabolomic profile of wine, which could be useful in future targeted studies
Reduction of Pyrrolizidine alkaloids content in aromatic seed drugs – Regulation and Practice
Get PDFDie auf Grund von Recherchen des Bundesamtes für Risikobewertung aufgezeigten Verunreinigungen von Kräutertees mit Pyrrolizidinalkaloiden (PA) und Tropanalkaloiden (TA) führten in den letzten drei Jahren zu vielen wissenschaftlichen und praktischen Arbeiten, um dieses Thema realistisch abbilden und eingrenzen zu können. Im gleichen Zeitraum wurden mehrere rechtliche Regelungen (Code of Practice), sowie auch Public Statements (EMEA) verfasst. Parallel hierzu wurden unter anderem in der Dr. Junghanns GmbH Korrekturmaßnahmen erarbeitet, um den Gehalt an PA und TA in Körnerfrüchten deutlich zu reduzieren.Im Rahmen diese Arbeiten wurde gezeigt, wie effektiv diese Maßnahmen bei der Nachreinigung von Praxischargen waren. Innerhalb der letzten zwei Jahre wurden mehr als 100 Chargen mit einer Gesamtmenge von 600 Tonnen (330 Tonnen vom kontrollierten biologischen Anbau und 270 Tonnen vom konventionellen Anbau) gereinigt. Möglichkeiten und Grenzen verschiedener Trennverfahren werden hier anhand der Beispiele von Bitterfenchel, Süßfenchel, Kümmel und Anis erläutert.Eine besondere Herausforderung stellte es dar, von dem bisherigen Reinheitsstandard von 99% zu einer Reinheit von 10 ppm und darunter zu gelangen. Dieses Ziel konnte bei über 90% aller aufgereinigten Chargen nach ein oder mehrmaligen Reinigungen erreicht werden. Hiermit wird nachgewissen, dass es möglich ist, mit entsprechender Expertise und erhöhten Kosten fast alle wegen PA und TA-Besatz gesperrten Chargen wieder verkehrsfähig zu machen.The contamination of herbal teas with pyrrolizidine alkaloids (PA-s) and tropane alkaloids (TA-s), identified three years ago by the Federal Office for Risk Assessment, was a start point for many research studies on assessment and characterization of the risk as well as the development of methods for monitoring and minimization of the presence of PA-s in food and feed. During the same period, several Guidelines and regulation (Code of Practice) as well as Public Statements (EMEA) were drafted.From the analysis of the available occurrence data and identification of potential risks along the entire process chain, Dr. Junghanns GmbH developed individual measures to significantly minimize the presence of PA-s and TA-s in aromatic seed drugs. Application of different mechanical separation processes on more than 100 batches (originated from the conventional and organic agriculture) of fennel, caraway, anise and other aromatic seed drugs shows how effective these measures were for the cleaning of highly contaminated batches. Possibilities and limits of different separation processes are explained using the examples of bitter fennel, sweet fennel, caraway and anise.It was a particular challenge to move from the previous purity standard of 99% to a purity of 10 ppm and below. This goal was achieved in more than 90% of all cleaned batches after one or more passes. This proves that it is possible to minimize the content of PA-s and TA-s, making so many rejected batches marketable again