Enhancement of degradation of fallen apple leaves

Leaves from organic apple trees were dipped with different organic materials and leaves were placed on the orchard floor in autumn. Leaf area and the amount of ascospores of Venturia inaequalis were measured in spring. The objective of this research was to find alternatives for urea that simulate the decomposition of apple leaves and reduces the asco-spore production. In both years urea gave an increase of the leaf degradation and a significant reduction of the number of ascospores. The antagonist Coniothyrium minitans had no significant effect on the ascospore production in both years but decreased the leaf degradation. Beet pulp showed a significant reduction of the number of spores but reduced the leaf degradation rate. Applying extra earthworms increased the degradation

Vinasse veelbelovend nieuw wapen tegen schurft

Schurftschimmel Venturia inaequalis vraagt maar liefst 70 procent van het middelengebruik in de fruitteelt. ‘Telers hebben ermee leren leven’, weet PPO-onderzoeker Bart Heijne. Hij is nauw betrokken bij een proef met vinasse, het nieuwste wapen tegen de vermaledijde Angstgegner van fruittelers. ‘De proef moet uitwijzen hoe groot de effectiviteit van vinasse werkelijk is.

REPCO contribution to the development of products for apple scab control

Natural compounds were sprayed according the RimPro scab warning system from start of bud break until the mid of June. Scab incidence was measured on the leaves and the fruit. Phytotoxicitiy and russet-ing was assessed. The natural compounds were sprayed together with sulphur and were compared with the standard biological fungicides copper hy-droxide and sulphur alone. Compound E73 + sulphur was the most effective on fruit. Armicarb and Resis-tim both sprayed with sulphur were comparable in efficacy with Funguran-OH. In our study laminarin (GL 32) did not shown any effect on the control of scab on apple

Field efficacy of new compounds to replace copper for scab control in organic apple production

Efficacy of compounds was investigated in field experiments in Denmark and the Netherlands according to EPPO guidelines. Some Yucca extracts and potassium bicarbonate had an efficacy similar to sulphur on leaves. Addition of sulphur to Yucca 1 and to potassium bicarbonate increased the level of efficacy to that of copper. This confirms results from earlier years. Although a dose increase resulted in better efficacy, this was more prominent for Yucca1 than for potassium bicarbonate

Influences of deep learning, need for cognition and preparation time on open- and closed-book test performance

Objectives The ability to master discipline-specific knowledge is one of the competencies medical students must acquire. In this context, 'mastering' means being able to recall and apply knowledge. A way to assess this competency is to use both open- and closed-book tests. Student performance on both tests can be influenced by the way the student processes information. Deep information processing is expected to influence performance positively. The personal preferences of students in relation to how they process information in general (i.e. their level of need for cognition) may also be of importance. In this study, we examined the inter-relatedness of deep learning, need for cognition and preparation time, and scores on open- and closed-book tests. Methods This study was conducted at the University Medical Centre Groningen. Participants were Year 2 students (n = 423). They were asked to complete a questionnaire on deep information processing, a scale for need for cognition on a questionnaire on intellectualism and, additionally, to write down the time they spent on test preparation. We related these measures to the students' scores on two tests, both consisting of open- and closed-book components and used structural equation modelling to analyse the data. Results Both questionnaires were completed by 239 students (57%). The results showed that need for cognition positively influenced both open- and closed-book test scores (beta-coefficients 0.05 and 0.11, respectively). Furthermore, study outcomes measured by open-book tests predicted closed-book test results better than the other way around (beta-coefficients 0.72 and 0.11, respectively). Conclusions Students with a high need for cognition performed better on open- as well as closed-book tests. Deep learning did not influence their performance. Adding open-book tests to the regularly used closed-book tests seems to improve the recall of knowledge that has to be known by heart. Need for cognition may provide a valuable addition to existing theories on learning

Influence of open- and closed-book tests on medical students' learning approaches

CONTEXT Two learning approaches are consistently distinguished in the literature: deep and surface learning. The deep learning approach is considered preferable. Open-book tests are expected to stimulate deep learning and to offer a possible way of handling the substantial growth in medical knowledge. In this study we test the hypothesis that open-book tests stimulate deep learning more than closed-book tests. METHODS Medical students in Years 2 (n = 423) and 3 (n = 306) participated in this study. They evaluated their preparation for open- and closed-book tests using the test for Deep Information Processing (DIP). This questionnaire consists of 24 items divided into three subscales: Critical Reading; Broaden One's Context, and Structuring. A paired t-test was used to analyse the data. RESULTS Both cohorts scored significantly higher when preparing for closed-book tests for the overall DIP score and on the Broaden One's Context and Structuring scales. Year 3 students also scored significantly higher on the Critical Reading scale when preparing for closed-book tests. Gender differences were found: women used deeper learning approaches than men. CONCLUSIONS Our hypothesis was not supported. In fact, the opposite was found: closed-book tests stimulated a deep learning approach more than open-book tests. Three possible explanations are: deep learning is particularly necessary for remembering and recalling knowledge; students feel more confident when preparing for closed-book tests, and students are more motivated to study for closed-book tests. The debate on the concept of deep learning in higher education should probably be renewed

Prevention and control of apple scab

Improved prevention and control of apple scab caused by Venturia inaequalis is aimed at without the use of copper containing products in the Repco-project. Substantial progress is made in selection of potential products against summer epidemics. A patent application is made for E73. New effective biocontrol agents are selected to reduce inoculum during winter. The product potassium bicarbonate has shown good efficacy and Repco contributes to the registration of this product in Europe. Earthworms tended to be stimulated to consume apple leaves treated with amino acids or beetpulp, especially when applied fresh under controlled environmental condi-tons

Milieueffecten van maatregelen gewasbescherming

In de in dit werkdocument beschreven modelstudie zijn berekeningen uitgevoerd over 15 teelten in de sectoren akkerbouw, vollegrondsgroenten, bloembollen fruitteelt en boomkwekerij. De milieueffectiviteit van de maatregelen is getoetst aan de hand van de reductie in Milieu Indicator Punten (MIP) voor de milieubelasting van oppervlaktewater door drift bij gewasbescherming (conform de toetsingsparameter in de Tussenevaluatie). Tevens is het effect op andere milieucompartimenten onderzocht. Voor de MIP-berekeningen is het Milieutechnisch en Economisch Bedrijfsmodel voor de Open Teelten (MEBOT) aangepast

Aanvullend advies op actualisatie maatregelen duurzame gewasbescherming 2009 : een selectie aan maatregelen waarmee op korte termijn het meest bereikt kan worden in de praktijk

PPO Wageningen UR, heeft in opdracht van het Ministerie van LNV in het kader van het convenant gewasbescherming maatregelen gecatalogiseerd die bijdragen aan het verlagen van de milieubelasting en aan het stimuleren van geïntegreerde gewasbescherming. Dit traject startte in 2004 en actualisatie vond plaats in 2006, 2007 en 2009. Na drie jaar actualisatie is een ontwikkeling in maatregelen zichtbaar. Deze publicatie bevat adviezen over maatregelen waarmee het meest bereikt wordt in de maatschappij

Biogenesis of mitochondrial porin

We review here the present knowledge about the pathway of import and assembly of porin into mitochondria and compare it to those of other mitochondrial proteins. Porin, like all outer mitochondrial membrane proteins studied so far is made as a precursor without a cleavble lsquosignalrsquo sequence; thus targeting information must reside in the mature sequence. At least part of this information appears to be located at the amino-terminal end of the molecule. Transport into mitochondria can occur post-translationally. In a first step, the porin precursor is specifically recognized on the mitochondrial surface by a protease sensitive receptor. In a second step, porin precursor inserts partially into the outer membrane. This step is mediated by a component of the import machinery common to the import pathways of precursor proteins destined for other mitochondrial subcompartments. Finally, porin is assembled to produce the functional oligomeric form of an integral membrane protein wich is characterized by its extreme protease resistance