Eindrapport "Haalbaarheid van directe elektriciteitsopwekking uit warmte met een thermo elektrische generator"

In het in dit rapport beschreven onderzoek wordt gekeken of warmte beter benut kan worden door gebruik te maken van thermo elektrische generatoren (TEG). TEG's maken gebruik van het zogenaamde Seebeck effect om warmte direct te converteren in elektriciteit. De doelstelling van het in dit rapport beschreven onderzoek is om een eerste globaal inzicht te geven in de technische en economische haalbaarheid van de toepassing van TEG in de glastuinbou

Health monitoring of plants by their emitted volatiles: A temporary increase in the concentration of nethyl salicylate after pathogen inoculation of tomato plants at greenhouse scale

This paper describes a method to alert growers of the presence of a pathogen infection in their greenhouse based on the detection of pathogen-induced emissions of volatile organic compounds (VOCs) from plants. Greenhouse-grown plants were inoculated with spores of a fungus to learn more about this concept. The specific objective of the present study was to determine whether VOCs are detectable after inoculation, and if so, to determine the time course of the concentrations of these compounds. To achieve this objective, we inoculated 60 greenhouse-grown tomato plants (Lycopersicon esculentum) with an aqueous suspension of Botrytis cinerea spores. Upon inoculation, the greenhouse air was sampled semi-continuously with a one hour time interval until 72 hours after inoculation (HAI). The samples were transferred to the laboratory and analysed using gas chromatography - mass spectrometry. Ten leaves were randomly selected to monitor the visible symptoms of infection. The severity of these visual symptoms was assessed at 0, 24, 48, and 72 HAI. Results demonstrated no detection of C6-compounds, and an almost constant concentration of all monoterpenes, most sesquiterpenes, and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene. However, the concentration of methyl salicylate increased 10-fold and 3-fold at 32 and 34 HAI respectively. At 24 HAI, 10% of the selected leaves showed mild symptoms while 20% of the selected leaves showed mild symptoms at 48 HAI. These results indicate that methyl salicylate might alert a grower of the presence of a B. cinerea infection of tomato plants at greenhouse scale. Further research is required to confirm these findings

Sniffing out disease

Research from Holland on early identification on plant disease from odours, provides a potential disease management tool in glasshouses. Combined with precision technology could these techniques be of relevance to paddock production

Validation of X-ray for borehole detection in intact trees

This research was financed by the Dutch Food Safety Authority (nVWA) and was carried out under assistance of Dutch General Inspection Service (NAK Tuinbouw), the Dutch Customs Laboratory and Siemen

Bruikbaarheid van non-destructieve detectietechnologieën voor routinematige inspecties

Routinematige inspecties binnen het fytosanitaire domein vinden doorgaans plaats door middel van steekproefsgewijze visuele inspecties van de producten. Hierbij wordt gelet op de symptomen en/of aanwezigheid van schadelijke organismen. De vraag is, of er geen sneller, goedkoop èn betrouwbaar alternatief is. De onderzochte technologieën zijn onderverdeeld in: detectie van beeld; detectie van geur; detectie van geluid. Een tweede fase heeft het doel gehad de potentie, haalbaarheid en beperkingen van een deze detectietechnieken voor routinematige inspecties in beeld te brengen, ondersteund door experimentele gegevens en hands-on ervaringen

Variation among volatile profiles induced by Botrytis cinerea infection of tomato plants

Botrytis blight caused by the fungus Botrytis cinerea is probably the most common disease of greenhouse-grown crops like tomato. Botrytis blight in tomato plants is mainly detected by visual inspection or destructive biochemical and molecular determinations. These methods are time consuming and not suitable for large sample sizes. In contrast we propose a fast and non-destructive detection method for plant diagnosis using volatiles as an early indicator of plant diseases. This report presents the variation in volatile production during mild and severe infection of tomato plants by the phytopathogenic fungus B. cinerea. Volatile emission from tomato plants before and after inoculation with B. cinerea were analyzed using on-line gas chromatography coupled to mass spectrometry. The emission was monitored from 2 to 72 hours after inoculation/exposure with a time resolution of 1 hour. The multivariate data was subjected to principal component analysis for fast interpretation of the variation between mild and severe infection symptoms. In addition a statistical test was performed to search for significant differences in headspace composition between the period before and after inoculation. Results show that there are no significant different compounds between headspace composition before and after inoculation when binning the data from mild and severe infected plants. This implies that the severity of infection has a significant effect on the main emission