'Xenia', a new pear cultivar from Moldava, first results in the Netherlands

The pear cultivar `Xenia¿ (synonym `Noiabriskaia¿) from Moldova is a selection from a cross between `Triomphe de Vienne¿ and `Nicolai Krier¿. In The Netherlands, `Xenia¿ has been tested since 2001. So far, trees have given early and high yields and required little thinning. Up to now, a very low to moderate susceptibility to scab (Venturia pirinia) and a very low susceptibility to fruit tree canker (Nectria galligena) have been observed. The trees showed a medium vigour and there was a low tendency to biennial bearing. With the relatively young trees, the average fruit size of `Xenia¿ fruits at full crop was 250-300 g. The harvest window was wide. Fruits of `Xenia¿ had a green ground colour at harvest and were moderately bronzed. `Xenia¿ had a spherical pear shape. The fruits had a strong fruit skin. The firmness was higher than that of `Conference¿. The juiciness varied from juicy to very juicy, depending on the maturity stage. `Xenia¿ had a good eating quality: fresh, slightly aromatic with a typical aroma. The storability of the fruits was very good and the shelf life of `Xenia¿ proved to be much better than of `Conference¿. Summarizing, the first results show a good potential for commercial fruit growing

Krymsk®1 (VVA-1), A dwarfing rootstock suitable for high density plum orchards in the Netherlands

Krymsk®:1 (Prunus tomentosa × Prunus cerasifera) was selected by Gennady Eremin at the Krymsk Breeding Station in Russia in 1966. Since 1994, it has been tested as a rootstock for several plum cultivars in The Netherlands. Graft compatibility was good for scion cultivars ‘Avalon’, ‘Excalibur’, ‘Jubileum’, ‘Opal’, and ‘Victoria’. Growth and production efficiency of plum on Krymsk®:1 was compared with that of plum on St. Julien A and, depending on the cultivar, also with Ferlenain, Otesani 8 and Pixy. With all cultivars, trees on rootstock Krymsk®:1 were by far the least vigorous, most precocious, and most production efficient. The production efficiency of ‘Avalon’ and ‘Excalibur’ on Krymsk®:1 grown for 10 years was 0.41 and 0.26 kg/cm² trunk cross sectional area, respectively, 3.4 and 4.3 times higher on Krymsk®:1 than on St. Julien A. With ‘Opal’ the production efficiency calculated over the first 5 years after planting was 2 to 3 times higher than on St. Julien A, but this difference became non significant after 7 years of cultivation. This was due to the much higher increase in production per tree during the 5th and 6th leaf of the trees on St. Julien A than on Krymsk®:1. Fruit size of ‘Opal’, ‘Avalon’ and ‘Excalibur’ was similar for trees grown on Krymsk®:1 and St. Julien A. With ‘Victoria’ fruit size was significantly larger (5 g) with Krymsk®:1 than with St. Julien A. Krymsk®:1 also increased the percentage of first pick by 15%, the sugar content by 9%, enhanced the development of fruit overcolour and reduced the percentage of fruits with gummosis in ‘Victoria’ plums. Dutch fruit growers show great interest in Krymsk®:1 as a rootstock for plum, as this rootstock makes high density plum orchards feasible. Growers switching to trees on Krymsk®1 have to take more care of their trees, especially in the first years after planting. Pruning, irrigation, and fertilization of the trees need much more attention in order to keep the trees vigorous and ensure good production levels. From 2002 to spring 2008, 120,000 plum trees on Krymsk®1 have been planted in The Netherlands and planting densities have increased from 830 up to 2,285 trees/ha. The main cultivar planted is ‘Victoria’

Model-based Joint Analysis of Safety and Security:Survey and Identification of Gaps

We survey the state-of-the-art on model-based formalisms for safety and security joint analysis, where safety refers to the absence of unintended failures, and security to absence of malicious attacks. We conduct a thorough literature review and - as a result - we consider fourteen model-based formalisms and compare them with respect to several criteria: (1) Modelling capabilities and Expressiveness: which phenomena can be expressed in these formalisms? To which extent can they capture safety-security interactions? (2) Analytical capabilities: which analysis types are supported? (3) Practical applicability: to what extent have the formalisms been used to analyze small or larger case studies? Furthermore, (1) we present more precise definitions for safety-security dependencies in tree-like formalisms; (2) we showcase the potential of each formalism by modelling the same toy example from the literature and (3) we present our findings and reflect on possible ways to narrow highlighted gaps. In summary, our key findings are the following: (1) the majority of approaches combine tree-like formal models; (2) the exact nature of safety-security interaction is still ill-understood and (3) diverse formalisms can capture different interactions; (4) analyzed formalisms merge modelling constructs from existing safety- and security-specific formalisms, without introducing ad hoc constructs to model safety-security interactions, or (5) metrics to analyze trade offs. Moreover, (6) large case studies representing safety-security interactions are still missing

Model-based Safety and Security Co-analysis: a Survey

We survey the state-of-the-art on model-based formalisms for safety and security analysis, where safety refers to the absence of unintended failures, and security absence of malicious attacks. We consider ten model-based formalisms, comparing their modeling principles, the interaction between safety and security, and analysis methods. In each formalism, we model the classical Locked Door Example where possible. Our key finding is that the exact nature of safety-security interaction is still ill-understood. Existing formalisms merge previous safety and security formalisms, without introducing specific constructs to model safety-security interactions, or metrics to analyze trade offs

Contribution of fruit research in the developments in Dutch fresh fruit chain

Due to the poor financial results of the fruit industry in the last decade, the changing trade structures and more consumer-driven fruit chains, Dutch fruit growers change their market behaviour. In these circumstances, the fruit industry itself and the applied fruit research are also changing. Applied Plant Research (PPO-Fruit) is involved in different projects related to consumer-driven fruit chain development and their side effects on fruit growers and firms. The purpose of this paper is to describe two projects about new Dutch fruit chains in which PPO-Fruit is involved and their impact on fruit growers and research. The projects are: a special variety chain, based on the Dutch apple variety Santana, which is scab resistant (Vf) and a regional crop chain ¿Betuwe framboos¿, (= Betuwe raspberry). It is clear that being part of a fruit chain means another way of working for the fruit growers and the other partners as well. They have to work according growing recipes and also recipes/procedures for other activities, like storage, packaging. This means a decrease of independence for the growers. PPO-Fruit works as a facilitator, a knowledge centre and executes experiments to solve new problem

Knelpunten in werkgeverschap en mogelijkheden tot verbetering : een participatief traject, doorlopen door fruittelers en onderzoekers

In het onderhavige onderzoek is het ‘people aspect’ van duurzaam en innovatief ondernemerschap verder onderzocht. Het doel was een tool te ontwikkelen waarmee werkgevers in de agrarische sector hun werkgeverschap in brede zin (arbeidsorganisatie, omgang met personeel, arbeidsomstandigheden en binden van het personeel aan het bedrijf) kunnen verbeteren. Het onderzoek is in twee fasen uitgevoerd, waarbij in de eerste fase nader gespecificeerd is welke aspecten van het werkgeverschap de belangrijkste knelpunten veroorzaken. Aansluitend is in de tweede fase in een interactief probleemoplossend traject met fruittelers op de gevonden knelpunten rondom het onderwerp ‘werkgeverschap’, doorlopen. Tevens hebben telers zelf nog onderwerpen aangedragen waarbij behoefte was aan kennis of vaardigheden

Rassenproef zwarte bessen 2011-2014

Vanaf 2011 heeft het Praktijkonderzoek Plant & Omgeving (PPO) sector Fruit te Randwijk het rassenonderzoek met zwarte bessen gedurende vier jaren voortgezet. Het doel is (nieuwe) rassen te zoeken en te toetsen onder Nederlandse (Zeeuwse) teeltomstandigheden, die een verbetering kunnen zijn van de huidige rassen voor wat betreft de productiviteit, de beskwaliteit en de gevoeligheid voor ziekten en plagen. Dit rapport is het eindverslag van het project dat eind 2014 is afgelopen

The tribological behaviour of skin equivalent materials and ex-vivo human skin during sliding contact with artificial turf

The use of synthetic materials for outdoor and indoor sport fields has increased over the last decades. Artificial turfs, commonly used on football fields, are basically infilled with recycled crumb rubber derived from old tires, the main of which are NBR (acrylonitrile butadiene rubber) and SBR (styrene-butadiene rubber) with fibers usually made of Polyethylene (PE) or Nylon. The use of these polymers for artificial turf designing purposes has caused controversy to whether their impact in human health, especially in skin abrasions during players sliding on the artificial turf. We have studied the tribological performance of different artificial human skin and real human skin against NBR, PE and Nylon 6.6 at different environmental conditions: normal conditions (25 ˚C and 50% of relative humidity) and high humidity conditions (37 ˚C and 80% of relative humidity) and forces of 2 and 4 N to achieve the association between friction and skin damage. The applied forces correspond to a range of pressures of 121 to 175 kPa and the experiments were conducted at 50 mm/s. The friction coefficient was obtained for different artificial skin samples: Lorica, Silicone L7350, pure PDMS, Cutinova and ESE (an epidermal skin equivalent developed by us), and these results were compared to those obtained from excised human skin samples obtained from healthy people after a surgery carried out at the Radboud Hospital of Nijmegen. Later on the human skin samples were analyzed with confocal microscopy and histological images to study the case of the surface properties of skin and determine any possible damage on the Stratum Corneum related to the tribological tests

Naar een meer duurzame, gezonde en natuurlijke teelt van zachtfruit : Verslag van een verkenning naar meer duurzame, milieuvriendelijke en gezonde teelt van zachtfruit op bedrijfsniveau

Verkenning naar meer duurzame, milieuvriendelijke en gezonde teelt van zachtfruit op bedrijfsniveau