Til dokument

Sammendrag

CONTEXT For high latitude countries like Norway, one of the biggest challenges associated with greenhouse production is the limited availability of natural light and heat, particularly in winters. This can be addressed by changes in greenhouse design elements including energy saving equipment and supplemental lighting, which, however, also can have a huge impact on investments, economic performance, resources used and environmental consequences of the production. OBJECTIVE The study aimed at identifying a greenhouse design from a number of feasible designs that generated highest Net Financial Return (NFR) and lowest fossil fuel use for extended seasonal (20th January to 20th November) and year-round tomato production in Norway using different capacities of supplemental light sources as High Pressure Sodium (HPS) and Light Emitting Diodes (LED), heating from fossil fuel and electricity sources and thermal screens by implementing a recently developed model for greenhouse climate, tomato growth and economic performance. METHODS The model was first validated against indoor climate and tomato yield data from two commercial greenhouses and then applied to predict the NFR and fossil fuel use for four locations: Kise in eastern Norway, Mære in mid Norway, Orre in southwestern Norway and Tromsø in northern Norway. The CO2 emissions for natural gas used for heating the greenhouse and electricity used for lighting were calculated per year, unit fruit yield and per unit of cultivated area. A local sensitivity analysis (LSA) and a global sensitivity analysis (GSA) were performed by simultaneously varying the energy and tomato prices. RESULTS AND CONCLUSIONS Across designs and locations, the highest NFR for both production cycles was observed in Orre (116.9 NOK m−2 for extended season and 268.5 NOK m−2 for year-round production). Fossil fuel was reduced significantly when greenhouse design included a heat pump and when extended season production was replaced by a year-round production. SIGNIFICANCE The results show that the model is useful in designing greenhouses for improved economic performance and reduced CO2 emissions from fossil fuel use under different climate conditions in high latitude countries. The study aims at contributing to research on greenhouse vegetable production by studying the effects of various designs elements and artificial lighting and is useful for local tomato growers who either plan to build new greenhouses or adapt existing ones and in policy formulation regarding incentivizing certain greenhouse technologies with an environmental consideration or with a focus on increasing local tomato production.

Til dokument

Sammendrag

Tomato greenhouses at high latitudes (≥58°North) require supplemental light to enable high yields and year-round production. Supplemental light systems can differ in lamp type, high-pressure sodium (HPS) or light emitting diode (LED), and also vary in lamp capacity. Based on a combined greenhouse climate, tomato yield, and greenhouse economics model, a methodology was developed, for determining the optimal supplemental light system, dependent on local climate and economic conditions. Two optimisation objectives were considered separately, maximal energy use efficiency (EUE) and maximal net financial result (NFR). The developed methodology was applied to four different greenhouse locations in Norway. At each location, both optimisation objectives were reached with LEDs. The optimal lamp capacities range from 256 to 341 μmol m−2 s−1 (maximal EUE) and 302–323 μmol m−2 s−1 (maximal NFR). The economically optimal lamp capacity is little sensitive to climate conditions. At the lamp type respective NFR maxima, LEDs resulted, on average, in 10% higher tomato yield, 102.2 NOK m−2 year−1 higher NFR, and 35% higher EUE. Consequently, switching from HPS lamps to LEDs enables increasing productivity, energy efficiency and profitability of greenhouse tomato production. Furthermore, the difference between EUE and NFR optima was, on average, 24% lower in terms of EUE and 56% lower in terms of NFR, when using LEDs instead of HPS lamps. On farm-scale, the proposed methodology can be used as decision-support-tool for selecting an efficient and profitable supplemental light system for greenhouse tomato production, dependent on local climate and economic conditions.

Til dokument

Sammendrag

Studies of whole-plant responses of tomato to light environments are limited and cannot be extrapolated from observations of seedlings or short-term crops in growth chambers. Effects of artificial light sources like high pressure sodium (HPS) and light emitting diodes (LED) are mainly studied as supplement to sunlight in greenhouses. Since natural sunlight is almost neglectable in Norway during wintertime, we could study effects of different types of artificial light on crop growth and production in tomato. The goal of this experiment was to quantify the effects of artificial HPS top-light, installed at the top of the canopy, and LED inter-light, installed between plant rows, on fresh and dry matter production and fruit quality of greenhouse tomatoes under controlled and documented conditions. Our aim was to optimize yield under different light conditions, while avoiding an unfavourable source-sink balance. Tomato plants were grown under HPS top light with an installed capacity of 161, 242 and 272 W m−2 combined with LED inter-light with an installed capacity of 0, 60 or 120 W m−2. We used stem diameter as a trait to regulate air temperature in different light treatments in order to retain plant vigour. Results show that both HPS top light and LED inter-light increased tomato yield. However, the positive effect of supplemental LED inter-light decreased at higher amounts of HPS top light. Under the conditions in this experiment, with neglectable incoming solar radiation, an installed amount of 242 Watt m-2 HPS top light and a daily light integral (DLI) of 30 mol m-2 day-1 resulted in best light use efficiency (in gram fresh tomato per mol). Addition of LED inter-light to HPS top light reduced light use efficiency. Results show that winter production using artificial light in Norway is more energy efficient compared to production under sunlight in southern countries. Results can be used for modelling purposes.

Til dokument

Sammendrag

Greenhouses are complex systems whose size, shape, construction material, and equipment for climate control, lighting and heating can vary largely. The greenhouse design can, together with the outdoor weather conditions, have a large impact on the economic performance and the environmental consequences of the production. The aim of this study was to identify a greenhouse design out of several feasible designs that generated the highest net financial return (NFR) and lowest energy use for seasonal tomato production across Norway. A model-based greenhouse design method, which includes a module for greenhouse indoor climate, a crop growth module for yield prediction, and an economic module, was applied to predict the NFR and energy use. Observed indoor climate and tomato yield were predicted using the climate and growth modules in a commercial greenhouse in southwestern Norway (SW) with rail and grow heating pipes, glass cover, energy screens, and CO2-enrichment. Subsequently, the NFR and fossil fuel use of five combinations of these elements relevant to Norwegian conditions were determined for four locations: Kise in eastern Norway (E), Mære in midwestern Norway (MW), Orre in southwestern Norway (SW) and Tromsø in northern Norway (N). Across designs and locations, the highest NFR was 47.6 NOK m−2 for the greenhouse design with a night energy screen. The greenhouse design with day and night energy screens, fogging and mechanical cooling and heating having the lowest fossil energy used per m2 in all locations had an NFR of −94.8 NOK m−2. The model can be adapted for different climatic conditions using a variation in the design elements. The study is useful at the practical and policy level since it combines the economic module with the environmental impact to measure CO2 emissions.

Til dokument

Sammendrag

Stavanger kommune og Rogaland Fylkeskommune har som mål at klimagassutslipp fra veksthusnæringen i regionen skal reduseres. Utslipp fra veksthus stammer hovedsakelig fra bruk av naturgass til oppvarming og CO2. Siden 2010 har flere gartnerier innført ulike klimatiltak, og undersøkelser blant 14 gartnerier viser en nedgang i utslipp per kg tomat produsert på 45 %. For at gartnerier skal innføre klimatiltak er lønnsomhet avgjørende, og gartnere i regionen oppgir at økonomi er den viktigste faktoren for å investere i klimavennlig teknologi. Veksthus som går over til bruk av strøm istedenfor gass, vil få størst lønnsomhet dersom de installerer økt belysning, siden dette også gir økte avlinger og inntekt. En utfordring med overgang til strøm er manglende kapasitet på nettet i regionen, og mange veksthus vil ikke få tilgang til strøm før dette er ferdig utbygget. Andre viktige, mulige kilder til fornybar energi er biogass og spillvarme, dette krever som regel samarbeid mellom flere næringer. Det er også mulig å redusere energiforbruket i veksthus gjennom optimal klimastyring og bruk av energigardiner, avfuktning, varmepumpe/varmeveksler, buffertank, og CO2-fangst. Det siste kan gjøre veksthusproduksjon CO2 nøytral eller negativ. Disse tiltakene krever ofte større investeringer, økt kunnskap og tilgang til kompetente rådgivere. Beregninger gjort i prosjektet «BioFresh» viser at de fleste av disse klimatiltakene bare vil være lønnsomme dersom gartneriene går over til helårsproduksjon. Spesielt for tomat kan dette bli en utfordring, da det per i dag i hovedsak selges importerte tomater i vintersesongen. De fleste veksthusene i regionen er små, og for disse vil klimatiltak bare bli lønnsomt dersom det foretas omfattende ombygging og utviding. Et alternativ for disse veksthusene kan være å starte med annen sesongproduksjon med lavere utslipp. Men mesteparten av veksthusarealet i regionen tilhører veksthus med mer enn 5000 m2, og for disse kan mange klimatiltak være lønnsomme. For å fremme investeringer i klimatiltak i regionen er det tilrådelig at det finnes gode økonomiske støtteordninger, hovedsakelig gjennom ENOVA og Innovasjon Norge. Det bør også tilrettelegges for godt samarbeid mellom vektshusprodusenter i regionen bl.a. for kunnskapsutveksling og markedsføringsstrategier. Det kan med fordel gjøres et arbeid for å fremme norske veksthusprodukter overfor forbrukere, for å øke omsetningen og gjøre det mulig for flere gartnerier å gå over til helårsproduksjon.

Til dokument

Sammendrag

Continuous light (CL) or a predominant nitrogen supply as ammonium (NH4+) can induce leaf chlorosis and inhibit plant growth. The similarity in injuries caused by CL and NH4+ suggests involvement of overlapping mechanisms in plant responses to these conditions; however, these mechanisms are poorly understood. We addressed this topic by conducting full factorial experiments with tomato plants to investigate the effects of NO3− or NH4+ supply under diurnal light (DL) or CL. We used plants at ages of 26 and 15 days after sowing to initiate the treatments, and we modulated the intensity of the stress induced by CL and an exclusive NH4+ supply from mild to strong. Under DL, we also studied the effect of nitrogen (N) deficiency and mixed application of NO3− and NH4+. Under strong stress, CL and exclusive NH4+ supply synergistically inhibited plant growth and reduced chlorophyll content. Under mild stress, when no synergetic effect between CL and NH4+ was apparent on plant growth and chlorophyll content, we found a synergetic effect of CL and NH4+ on the accumulation of several plant stress hormones, with an especially strong effect for jasmonic acid (JA) and 1-aminocyclopropane-1-carboxylic acid (ACC), the immediate precursor of ethylene, in xylem sap. This modulation of the hormonal composition suggests a potential role for these plant hormones in plant growth responses to the combined application of CL and NH4+. No synergetic effect was observed between CL and NH4+ for the accumulation of soluble carbohydrates or of mineral ions, indicating that these plant traits are less sensitive than the modulation of hormonal composition in xylem sap to the combined CL and NH4+ application. Under diurnal light, NH4+ did not affect the hormonal composition of xylem sap; however, N deficiency strongly increased the concentrations of phaseic acid (PA), JA, and salicylic acid (SA), indicating that decreased N concentration rather than the presence of NO3− or NH4+ in the nutrient solution drives the hormone composition of the xylem sap. In conclusion, N deficiency or a combined application of CL and NH4+ induced the accumulation of JA in xylem sap. This accumulation, in combination with other plant hormones, defines the specific plant response to stress conditions.

Til dokument

Sammendrag

In regions with intensive agricultural production, large amounts of organic waste are produced by livestock animals. Liquid digestate from manure-based biogas production could potentially serve as fertilizer if integrated with closed horticultural irrigation systems. The aim of this experiment was to investigate how fertilizer based on liquid biogas by-products of pig manure digestion can affect the growth and production of tomato plants. Integration of a nitrification bioreactor presumes a significantly lower concentration of nutrient solutions and a higher level of oxygenation than classical mineral cultivation. Therefore, additional controls were included. We compared plant growth and fruit quality traits of tomato plants grown in a hydroponic solution with organic fertilizer with two levels of mineral fertilizer. The tomatoes grown with organic waste-based liquid fertilizer showed reduced growth rates but increased mean fruit size, resulting in no significant change in total yield compared with high-mineral cultivation. The growth rate was similarly reduced in plants cultivated with low-mineral fertilizer. Plants cultivated with organic waste-based fertilizer had high Cl− concentration in xylem sap, leaves, and, ultimately, fruits. The leaves of plants cultivated with organic waste-based fertilizer contained higher concentrations of starch and soluble carbohydrate and low concentrations of phosphorous (P) and sulfur (S). The plants grown with organic waste-based or low-mineral medium showed significantly poorer fruit quality than the plants cultivated with the high-mineral solution. The low-mineral treatment increased xylem sap contribution to fruit weight because of higher root power. The organic waste-based fertilization did not change the root power but increased fruit size. In conclusion, organic waste-based cultivation is a possible solution for sustainable plant production in greenhouses. However, additional adjustment of nutrient supply is required to improve fruit quality.

Til dokument

Sammendrag

A greenhouse climate-crop yield model was adapted to include additional climate modification techniques suitable for enabling sustainable greenhouse management at high latitudes. Additions to the model were supplementary lighting, secondary heating and heat harvesting technologies. The model: 1) included the impact of different light sources on greenhouse air temperature and tomato production 2) included a secondary heating system 3) calculated the amount of harvested heat whilst lighting was used. The crop yield model was not modified but it was validated for growing tomato in a semi-closed greenhouse equipped with HPS lamps (top-lights) and LED (inter-lights) in Norway. The combined climate-yield model was validated with data from a commercial greenhouse in Norway. The results showed that the model was able to predict the air temperature with sufficient accuracy during the validation periods with Relative Root Mean Square Error <10%. Tomato yield was accurately simulated in the cases under investigation, yielding a final production difference between 0.7% and 4.3%. Lack of suitable data prevented validation of the heat harvest sub-model, but a scenario is presented calculating the maximum harvestable heat in an illuminated greenhouse. Given the cumulative energy used for heating, the total amount of heating pipe energy which could be fulfilled with the heat harvestable from the greenhouse air was around 50%. Given the overall results, the greenhouse climate(-crop yield) model modified and presented in this study is considered accurate enough to support decisions about investments at farm level and/or evaluate beforehand the possible consequences of environmental policies.

Til dokument

Sammendrag

Hyperspectral imaging has many applications. However, the high device costs and low hyperspectral image resolution are major obstacles limiting its wider application in agriculture and other fields. Hyperspectral image reconstruction from a single RGB image fully addresses these two problems. The robust HSCNN-R model with mean relative absolute error loss function and evaluated by the Mean Relative Absolute Error metric was selected through permutation tests from models with combinations of loss functions and evaluation metrics, using tomato as a case study. Hyperspectral images were subsequently reconstructed from single tomato RGB images taken by a smartphone camera. The reconstructed images were used to predict tomato quality properties such as the ratio of soluble solid content to total titratable acidity and normalized anthocyanin index. Both predicted parameters showed very good agreement with corresponding “ground truth” values and high significance in an F test. This study showed the suitability of hyperspectral image reconstruction from single RGB images for fruit quality control purposes, underpinning the potential of the technology—recovering hyperspectral properties in high resolution—for real-world, real time monitoring applications in agriculture any beyond.

Sammendrag

Recycling of waste fractions from farms and greenhouses might reduce environmental pollution. However, recycling of nutrient solution in greenhouse is risky due to danger of disease spread. Nitrification bacteria can be used for aerobic conversion of ammonia to nitrate in organic waste and may function as stable microbial community protecting against pathogen attacks by enhancing induced systemic resistance of plants. We developed a hydroponic cultivation system “Organoponics” allowing growth of tomato plant on organic fertilizer with recirculation of nutrient solution. Liquid by-product of biogas production has been used as organic fertilizer. A moving-bed bioreactor was integrated in the system for aerobic nitrification of ammonia. Influence of fertilizer composition (organic, mineral matching organic, standard mineral) and addition of plant growth promoting bacteria on biomass distribution, tomato fruit quality were investigated. Plants grown on organic fertilizer were more generative with largest root index. They also produced fruits with significantly larger average size along whole cluster. Addition of the bacteria to root rhizosphere improved yield and quality parameters of plants received organic fertilization and negatively affected the same parameters in plants received mineral fertilization.

Til dokument

Sammendrag

We investigated the effect of supplemental LED inter-lighting (80% red, 20% blue; 70 W m−2; light period 04:00–22:00) on the productivity and physiological traits of tomato plants (Flavance F1) grown in an industrial greenhouse with high pressure sodium (HPS) lamps (235 W m−2, 420 µmol m−2 s−1 at canopy). Physiological trait measurements included diurnal photosynthesis and fruit relative growth rates, fruit weight at specific positions in the truss, root pressure, xylem sap hormone and ion compositions, and fruit quality. In the control treatment with HPS lamps alone, the ratio of far-red to red light (FR:R) was 1.2 at the top of the canopy and increased to 5.4 at the bottom. The supplemental LED inter-lighting decreased the FR:R ratio at the middle and low positions in the canopy and was associated with greener leaves and higher photosynthetic light use efficiency (PLUE) in the leaves in the lower canopy. The use of LED inter-lighting increased the biomass and yield by increasing the fruit weight and enhancing plant growth. The PLUE of plants receiving supplemental LED light decreased at the end of the light period, indicating that photosynthesis of the supplemented plants at the end of the day might be limited by sink capacity. The supplemental LED lighting increased the size of fruits in the middle and distal positions of the truss, resulting in a more even size for each fruit in the truss. Diurnal analysis of fruit growth showed that fruits grew more quickly during the night on the plants receiving LED light than on unsupplemented control plants. This faster fruit growth during the night was related to an increased root pressure. The LED treatment also increased the xylem levels of the phytohormone jasmonate. Supplemental LED inter-lighting increased tomato fruit weight without affecting the total soluble solid contents in fruits by increasing the total assimilates available for fruit growth and by enhancing root activity through an increase in root pressure and water supply to support fruit growth during the night.

Sammendrag

Å bygge veksthus på tak i byer kan ha flere fordeler. Redusert avstand til forbrukere gir ferskere varer og mindre kostnader og forurensing forbundet med transport og lagring. Dette er spesielt viktig for byer som ligger langt fra der maten produseres. Veksthus i byer kan også gi den urbane befolkningen muligheten til å lære mer om hvordan mat dyrkes. Ved å bygge veksthus på tak istedenfor på bakken spares arealer som i stedet kan brukes til jordbruk, grøntområder eller andre typer boliger. Et veksthus på tak som er integrert med den øvrige bygningen, kan også utnytte varmen fra etasjene under, noe som vil være energibesparende.

Til dokument Til datasett

Sammendrag

There is a large potential in Europe for valorization in the vegetable food supply chain. For example, there is occasionally overproduction of tomatoes for fresh consumption, and a fraction of the production is unsuited for fresh consumption sale (unacceptable color, shape, maturity, lesions, etc.). In countries where the facilities and infrastructure for tomato processing is lacking, these tomatoes are normally destroyed, used as landfilling or animal feed, and represent an economic loss for producers and negative environmental impact. Likewise, there is also a potential in the tomato processing industry to valorize side streams and reduce waste. The present paper provides an overview of tomato production in Europe and the strategies employed for processing and valorization of tomato side streams and waste fractions. Special emphasis is put on the four tomato-producing countries Norway, Belgium, Poland, and Turkey. These countries are very different regards for example their climatic preconditions for tomato production and volumes produced, and represent the extremes among European tomato producing countries. Postharvest treatments and applications for optimized harvest time and improved storage for premium raw material quality are discussed, as well as novel, sustainable processing technologies for minimum waste and side stream valorization. Preservation and enrichment of lycopene, the primary health promoting agent and sales argument, is reviewed in detail. The European volume of tomato postharvest wastage is estimated at >3 million metric tons per year. Together, the optimization of harvesting time and preprocessing storage conditions and sustainable food processing technologies, coupled with stabilization and valorization of processing by-products and side streams, can significantly contribute to the valorization of this underutilized biomass.

Til dokument

Sammendrag

Non-destructive tools for evaluating the lycopene content in tomatoes are of great interest to the entire fruit chain because of an increasing demand for beneficial health products. With the aim of developing compact low-cost reflectance sensors for lycopene determination, we compared Partial Least Squares (PLS) prediction models by using either directional or total reflectance in the 500–750 nm range. Directional reflectance at 45° with respect to the LED lighting direction was acquired by means of a compact spectrometer sensor. Total reflectance was acquired through a 50-mm integrating sphere connected to a spectrometer. The analysis was conducted on two hydroponic greenhouse cultivated red tomato varieties, namely the large round ‘Dometica’ (average diameter: 57 mm) and the small cherry ‘Juanita’ (average diameter: 26 mm). For both varieties, the spectral variance of directional reflectance was well correlated to that of total reflectance. The performances of the PLS prediction models were also similar, with R2 of cross-validation between 0.73 and 0.81. The prediction error, relative to the mean lycopene content of full ripe tomatoes, was similar: i.e. around 16–17% for both varieties and sensors. Our results showed that directional reflectance measured by means of portable, low-cost and compact LED-based sensors can be used with an adequate precision for the non-destructive assessment of lycopene in tomatoes.

Til dokument

Sammendrag

Lunch canteens and their salad bars are an important arena for sales and consumption of vegetables including herbs. One major Norwegian canteen operator had a turnover of more than seven thousand tons of fresh vegetables in 2016, with lettuce, tomato, potato, cucumber and bell pepper being the most important species. A typical lunch meal included about 260 g vegetables including potatoes. Vegetables used in 450 canteens were either green, yellow, orange, red, purple/dark or colorless, and consisted of pigments of chlorophylls, carotenoids, anthocyanins and betalains. The total pigment content in the 60 most abundant vegetables was calculated to be 14.5-28.3 mg 100 g-1 FW. Of all vegetables in the canteens, 60% were found to be green. The intake of chlorophyll through one lunch meal was estimated to be 46 mg. Lettuce was found to be the single most important source of chlorophylls as this species was consumed in high amounts and made up 20% of the vegetables in a lunch meal. Carotenoids was found in all colored vegetables except the purple/dark ones and an estimate revealed an intake of 15 mg total carotenoids from lunch vegetables. Tomato was found to be the most important carotenoid source representing 44% of the total intake. Due to high pigment concentrations and popularity of red beets in the salad bars, the intake of betalains through a lunch meal was estimated to be 3 mg, similar to the total intake of anthocyanins from vegetable species.

Til dokument

Sammendrag

The project “Sustainable food production through quality optimized raw-material production and processing technologies for premium quality vegetable products and generated by-products” [SUNNIVA] aimed at the development of a sustainable food system from production to consumption, addressing the entire food supply chain for the vegetables tomato and Brassicae. The goal was better utilisation of the vegetable raw materials, reduced energy and water consumption, higher profitability and healthier food. This was achieved by providing various valorisation strategies to reduce waste and limiting environmental impact. Preservation of the intrinsic health-beneficial phytochemicals present in the raw material in order to improve the nutritional properties of vegetable food products was central in the project. The project contained optimization of harvest time and pre-processing storage conditions, development of novel mild processing design based on modelling, and a two-track valorisation strategy. SUNNIVA has demonstrated how the various residual raw materials can be exploited to the full: Either directly for sustainable production of healthy food (as a refined product or an ingredient), or indirectly by bringing it back into the food chain (as organic fertilizers and soil amendment products) in order to generate renewed primary production with minimal environmental impact.

Til dokument

Sammendrag

Rapporten beskriver resultatene fra et forprosjekt med mål å undersøke muligheter for norsk veksthusproduksjon av eksotiske grønnsaker til innvandrerbutikker. Prosjektet ble gjennomført i samarbeid med ‘Indian Society of Rogaland’ og støttet av Fylkeskommune Rogaland gjennom Handlingsprogram Næring 2016.

Sammendrag

Dagens produksjonsmetode av veksthusgrønnsaker gir betydelig utslipp av næringsstoffer. Det er en situasjon som er uønsket og kan føre til forurensing av nærmiljøet, bruk av for mye næringsstoffer og økonomisk tap for produsenter. Registreringer viser at avrenningsprosenter kan variere mellom 30 og 40 % i tomat og agurk. Tapet av næringsstoffer ble estimert. Det ble påvist at det er mulig å begrense mengde avrenningsvann ved å tilpasse vanningsteknikk. Men bruk av denne vanningsteknikken forutsetter at vanntilførselen er 100% nøyaktig. Avvik vil ha store konsekvenser for avling og/eller kvalitet av produktene og dermed for økonomien for den enkelte produsent, og er dermed enda ikke forsvarlig. Resirkulering av avrenningsvann er teknisk mulig. Det vil redusere avrenningen med tilnærmet 100%. Desinfeksjon av avrenningsvann er helt nødvendige for å unngå spredning av sykdommer. Det er god erfaring med gode teknikker fra utlandet, og teknikkene er beskrevet i rapporten. Resirkulering vil kreve en investering i bl.a. oppsamlingstanker, rensesystemer og en ny gjødselblander. Denne investeringen vil øke produksjonskostnader for gartnerier med et gjennomsnittsareal på 1000-3000 m2 med ca 25 %. Besparelsen av utgifter for gjødsling og vann er estimert på 0,10 til 0,15 nok/kg. Rapporten konkluderer at det er pr i dag for de fleste bedrifter ulønnsom å investere i et slikt vanningssystem.

Til dokument

Sammendrag

The SUNNIVA project aims to increase the overall sustainability of vegetable processing by providing valorisation strategies to reduce waste and limiting environmental impact, while improving the nutritional properties of vegetable food products. Results obtained during the first project year indicate that; (i) The waste and by-product fractions of cabbage, tomato and black salsify have a great potential to be better utilized in the food processing chain and to serve as valuable sources for health beneficial phytochemicals (HBPC), and (ii) that tomato and grape seed press cakes have an interesting plant nutritional (NPK) profile, which makes them suitable candidates as raw material in soil amendments. Further, raw materials from tomato and cabbage, in terms of cultivars and morphological parts, has been assessed for HBPC and nutritional value as an effect of N-fertilization and processing. Experimental data for deriving numerical thermal models for agitated and static retort are obtained. Mapping of the most important underutilized vegetable biomass streams in partnering countries are under way. The development of non-destructive tools for rapid HBPC measurements in cabbage and tomato is promising, but some more calibration/validation of the method is necessary. One year into the 3-year project, we conclude that progress has been satisfactory.

Sammendrag

  Marine Bioproducts AS, i samarbeid med Bioforsk, fekk støtte frå Regionalt Forskingsfond Vest til forprosjektet "Marine bioaktive peptidar for økologisk jordbruk". Ein viktig del av forprosjektet var å prøva om marine bioaktive peptid frå laksemuskel kunne ha verknad på plantevekst og kvalitetsfaktorar i bær.  

Til dokument

Sammendrag

Tomato plants (Solanum lycopersicum, cv. Suzanne) were subjected to complete nutrient solution or a solution without nitrogen (N), and placed at different temperatures and light conditions to test the effects of environment on flavonoids and caffeoyl derivatives and related gene expression. N depletion during 4-8 days resulted in enhanced levels of flavonoids and caffeoyl derivatives. Anthocyanins showed pronounced increased levels when lowering the growth temperature from 24 degrees C to 18 degrees C or 12 degrees C. Flavonol levels increased when the light intensity was increased from 100 mu mol m(-2) s(-1) to 200 mu mol m(-2) s(-1) PAR. Synergistic effects of the various environmental factors were observed. The increase in content of quercetin derivatives in response to low temperatures was only found under conditions of N depletion, and especially at the higher light intensity. Expression of structural genes in the phenylpropanoid and flavonoid pathways, PAL (phenylalanine ammonia lyase), CHS (chalcone synthase), F3H (flavanone 3-hydroxylase), and FLS (flavonol synthase) increased in response to N depletion, in agreement with a corresponding increase in flavonoid and caffeoyl content. Expression of these structural genes generally also increased in response to lower temperatures. As indicated through expression studies and correlation analysis, effects of N depletion were apparently mediated through the overall regulators of the pathway the MYB transcription factor ANT1 (ANTHOCYANIN 1) and SlJAF13 (a bHLH transcription factor orthologue of petunia JAF13 and maize RED genes). A PAL gene (PAL6) was identified, and correlation analysis was compatible with PAL6 being an actively expressed gene with function in flavonoid synthesis. (C) 2009 Elsevier Ltd. All rights reserved.

Til dokument

Sammendrag

The flavonoid pathway is known to be up-regulated by different environmental stress factors. Down-regulation of the pathway is much less studied and is emphasized in the present work. Flavonoid accumulation was induced by exposing plants for 1 week to nitrogen depletion at 10 degrees C, giving high levels of anthocyanins and 3-glucoside-7-rhamnosides, 3,7-di-rhamnosides and 3-rutinoside-7-rhamnosides of kaempferol and quercetin. Flavonol accumulation as influenced by temperatures and nitrogen supply was not related to the glycosylation patterns but to the classification as quercetin and kaempferol. When nitrogen was re-supplied, transcripts for main regulators of the pathway, PAP1/GL3 and PAP2/MYB12, fell to less than 1 and 0.1% of initial values, respectively, during 24 h in the 15-30 degrees C temperature range. Anthocyanins showed a half-life of approximately 1 d, while the degradation of flavonols was much slower. Interestingly, the initial fluxes of anthocyanin and flavonol degradations were found to be temperature-independent. A kinetic model for the flavonoid pathway was constructed. In order to get the observed concentration-temperature profiles as well as the temperature compensation in the flavonoid degradation flux, the model predicts that the flavonoid pathway shows an increased temperature sensitivity at the end of the pathway, where the up-regulation by PAP/GL3 has been found to be largest.

Sammendrag

Forsøk gjennomført ved Biofrosk Vest Særheim viser at angrepet av P. aphanidermatum kan reduseres kraftig ved å senke mattetemperaturen, men bare dersom dette blir gjort gjennom hele kulturperioden. Også bedre kontroll og styring av pH i perioden fra utplanting til begynnende høsting, kan være en enkel og effektiv måte for å redusere angrepet av P. aphandiermatum

Sammendrag

Fem nye mjøldoggtolerante sorter ble vurdert i forhold til målesorten "Aviance" i paraplykultur våren 2008. Resultatene viser at de nye sortene ikke er noe vesentlig bedre alternativ. "Aviance" anbefales fortsatt som hovedsort til vårplanting, mens "Shakira" fortsatt er hovedsort for sommer- og høstplanting i paraply.

Sammendrag

Fem nye mjøldoggtolerante sorter ble sammenlignet med målesorten "Rapides" i lyskultur med nedsenking og planting om våren. Resultatene viste at ingen av sortene var et klart bedre alternativ enn "Rapides".

Sammendrag

Fem nye mjøldoggtolerante sorter ble sammenlignet med målesorten "Rapides" i lyskultur med nedsenking og planting om høsten. Det ble ikke funnet forskjell i avling mellom sortene. Selv om det ble påvist forskjeller i agurkkvalitet, tidlighet og mjøldoggtoleranse, var ingen av sortene et klart bedre alternativ enn "Rapides".

Sammendrag

Omlegging til økologiskproduksjon er lønnsomt for tilpasningsdyktige produsenter av veksthusgrønnsaker. Det viser resultater fra forsøkene på Bioforsk Vest Særheim samt erfaringer fra storskalaforsøk i gartnerier.

Sammendrag

The effects of photoperiod (12, 13, 14, 15 or 16 h), day-temperature (12, 15, 18, 24 or 27"C) and night-temperature (6, 9 or 12 oC) and their interactions on flower and inflorescence emergence were investigated by exposing 4 week old runner planst of strawberry cvs. Korona and Elsanta during a period of 3 weeks. A daily photoperiod of 12 or 13 h resulted in the highest numbers of plants with emerged flowers. A photoperiod of 14 h or more strongly reduced this number, while no flowers emerged at a photoperiod of 16 h. Plants exposed to photoperiods of 12 or 13 h flowered earlier and had longer flower trusses. A day-temperature of 18 oC and a night temperature of 12 oC were optimal for plants to emerge flowers and resulted in shortest time to flowering. A night temperature of 6 oC strongly reduced the number of plants that emerged flowers, especially when combined with lower day-temperatures. Photoperiod and temperature had no effect on the number of inflorescences, all flowering plants produced on average one inflorescence. The number of flowers on the inflorescence increased with decreasing day temperature and when photoperiod was raised fra 12 to 15 h. In general, `Korona" was more sensitive to photoperiod and temperature than `Elsanta", and had a lower optimal day-temperature for flower emergence. Results of this experiment may be used to produce high quality plant material or to define optimal conditions when combining flower induction and fruit production.

Sammendrag

Veiledningsprøvinger i agurk høsten 2006 viste klare forskjeller mellom sortene både i avling, kvalitet og mjøldoggtoleranse. Fem nye mjøldoggtolerante sorter ble vurdert i forhold til målesorten "Aviance" i paraplykultur. Resultatene viser at de nye sortene har bedre holdbarhet og mjøldoggtoleranse enn "Aviance*. Når det vurderes både avling, kvalitet og mjøldoggtoleranse, er den nye sorten "Shakira" et bedre valg enn "Aviance

Til dokument

Sammendrag

Pythium aphanidermatum er et rotpatogen som gir aggressiv rotråte i veksthusagurk (Cucumis sativus). Rapporten beskriver resultater fra forsøk gjennomført ved Bioforsk Plantehelse/Vest Særheim med utprøving av kjemiske og biologiske alternativer for bekjempelse av P. aphanidermatum. Seks preparater er utprøvd : Prestop (Gliocladium catenulatum), Mycostop (Streptomyces griseovirides), Previcur N (prepamocarb), Aliette 80 WG (fosetyl- Al) og Resistim (fosfitt). Resultatene viser at behandling med Resistim og en kombinasjon av Previcur N og Resistim fører til redusert angrep av P. aphanidermatum hos agurksmåplanter. Bruk av Aliette 80 WG (1/2 dose) og Resistim ser ut til å hemme angrepet også etter utplanting. Ved behandling med Resistim og kombinasjonen av Previcur N og Resistim klarte plantene å vokse seg gjennom begynnende angrep og synlige rothalsskader forsvant. Mycostop, Prestop og Aliette hadde i disse forsøkene ikke tilsvarende god effekt. Forprosjektet viser at det er vanskelig å eliminere angrep av P. aphanidermatum utelukkende ved bruk gjødsel, kjemiske eller biologiske fungicider. Tilfredstillende desinfeksjon, rengjøring, dyrkingspraksis og temperaturvalg er viktige faktorer som det må arbeides systematisk videre med for å kunne redusere angrepene av P. aphanidermatum i Norsk agurkproduksjon.

Til dokument

Sammendrag

Forsøkene undersøkte virkningen av vekstduk og mulchtype på avling og kvalitetskomponenter i ‘Korona’ jordbær ved dyrking i tunnel i to år. Tunnelen førte til redusert innstråling (PAR), særlig i det andre avlingsåret, og enkelte dager så mye at det ville ha negativ effekt på avling. Vekstduk reduserte fruktstørrelse og avling i det første året, mens hvit mulch ikke hadde noen klar effekt på totalavling. Imidlertid ga hvit mulch større frukter enn brun mulch i det første avlingsåret, og en større andel frukter større enn 25 mm i begge årene. Når bladverket var utvokst ble temperaturen i plantebestanden høyere over hvit enn over brun plastfoliemulch på dager med sterk innstråling og %RF ble samtidig kraftig redusert. Temperaturen under vekstduken ble betydelig høyere enn uten vekstduk, og i det første året så høy at plantene ble utsatt for varmestress. I begge årene økte klorofyllinnholdet i bladene ved dyrking på hvit sammenlignet med brun folie. I det første året ga vekstduk økt klorofyllinnhold, mens forholdet var motsatt i det andre året. Fruktkvaliteten ble påvirket både av fruktorden, mulchtype og vekstduk.

Til dokument

Sammendrag

Norsk gartnerinæring bruker anslagsvis 1 000 GWh per år. Planteproduksjon i veksthus her i landet har stort behov for elektrisk energi og avhengig av kultur og produksjonsopplegg varierer andelen elektrisk energi fra 50-80 %.. Naturgass er blitt et supplement til elektrisk energi i Rogaland de siste årene. I arbeidet med å sikre veksthusnæringen tilgang på elektrisk kraft kan kraft/varme-anlegg være et alternativ, ettersom plantene kan nyttiggjøre seg CO2 i avgassen. I utredningen er det skissert et forsøksanlegg for testing av energiløsninger for veksthus basert på naturgass og aktuelt utstyr for produksjon og oppsamling av energi for senere bruk.

Sammendrag

Dyrking i tunnel medfører en forandring i dyrkingsklima, noe som vil påvirke tidlighet, avling og kvalitet. Det er vist tidligere at  dyrking av jordbær i tunnel under norske forhold fører til mer stabile høsteforhold og betydelig mindre problemer med fruktråte. Imidlertid var det lite klarlagt hvordan klimafaktorer som temperartur og lys påvirker fruktkvalitet ved dyrking i tunnel. Det var også lite kunnskap om hvordan kulturtiltak som påvirker mikroklima i plantebestanden, påvirker fruktkvalitet. I et nylig avsluttet prosjekt som ble finansiert av Norges Forskningsråd er endel av disse spørsmålene belyst.

Sammendrag

The effects of photoperiod (10, 12, 16, 20 or 24 h), day-temperature (12, 15, 18, 24 or 30°C), the number of short days (14, 21 or 28 days), plant age (4, 8 or 12 weeks) and their interactions on flower and inflorescence initiation were investigated in strawberry cv. Korona. No flowers emerged in plants exposed to photoperiods of 16, 20 or 24 h or to a short day treatment for 14 days. All plants exposed to short days at daily photoperiods of 10 or 12 h for 21 days or longer, emerged flowers at temperatures between 12 and 18°C. A further increase in temperature led to a drastic decrease in the total number of flowers per plant. A short day treatment (10 or 12 h photoperiod) of 28 days resulted in highest numbers of inflorescences and flowers per plant, while a short day treatment of 21 days resulted in the highest numbers of flowers per inflorescence. Complete flower induction was observed in only 4-week-old runner plants. The number of inflorescences and the number of flowers per inflorescence increased with plant age. However, the start of flowering was delayed with increasing plant age. Results clearly demonstrate interactions between photoperiod, temperature, duration of short day treatment and plant age on flowering. This knowledge may be used to produce flower-induced plants in a greenhouse or to develop a model for predicting flower behaviour in the field.

Sammendrag

In order to increase the production of organic vegetables in Norway, a project was started to facilitate the transistion from conventional to organic greenhouse production. A growing system based on ecological production principles was tested at Bioforsk Vest Særheim. Results showed that a growing system with limited beds, using 75 l/m2 of an organic growth substrate and 24 l/m2 locally available cattle slurry as additional fertilizer, resulted in a yield comparable to traditional greenhouse tomato production. Fertilizing three times a week with 0,5 l/m2 cattle slurry in combination with sprinkler irrigation controlled by light integration showed to be equally effective as fertilizing using standard mineral nutrition. Results give rise to an economical production of organic greenhouse tomatoes.

Sammendrag

The content of chalconaringenin, chlorogenic acid, rutin, ascorbic acid, lycopene and b-carotene were analyzed during postharvest- and vine-ripening of cherry tomatoes (Lycopersicon esculentum Mill.) (cv. Jennita) produced in a greenhouse. A remarkable decrease in the content of chalconaringenin took place during postharvest ripening. The tomatoes were found to contain 15.26 mg 100 g-1 fresh weight (FW) at harvest, but held only 0.41 mg after three weeks at 20 ºC in darkness. Chalconaringenin did not convert into naringenin. The content of chlorogenic acid fell from 0.51 to 0.06 mg 100 g-1 FW at the same conditions. The content of rutin and that of total phenolics remained stable during postharvest ripening. The amounts of lycopene as well as b-carotene and ascorbic acid increased during postharvest ripening. No significant change in the amount of methanol soluble antioxidants or total soluble solids was found during postharvest ripening of the tomato fruits. During vine ripening, the total amount of phenolics and that of soluble solids (%-Brix) increased. The content of phenolics correlated well with the content of methanol soluble antioxidants (p

Sammendrag

Plant production in northern countries is hampered by a short growing season. In Norway, waterpower provides relatively cheap and renewable energy that can be used for artificial lighting. Light is often the limiting factor for plant growth and productivity in greenhouses, and the use of artificial radiation became already early last century an important subject for investigation in Norway. Development of different lamp types gave rise to investigations of light quality on plant performance. Artificial irradiation was primarily confined to plant propagation. Large-scale irradiation of entire crops started in Norway in 1989 and has given rise to a marked increase in winter production of flowers and vegetables. The Norwegian Crop Research Institute performs applied research in all chains of plant production. Research on greenhouse production is coordinated from Særheim Research Centre. Særheim is located in the southwest of Norway where 80% of tomatoes and 50% of the Norwegian cucumbers are produced. Research on the use of artificial light for cucumber production started here in 1990. After that, production systems for lettuce, herbs, strawberry, tomato and sweet pepper were developed. Growers that nowadays use our system for year-round production of cucumbers have increased their yield from 40 to 160 kg/m2. In 2004, we were the first to reach an annual yield of 100 kg/m2 in tomato. In our applied research, consumer and wholesaler demands define the quality aspects of food to be produced. Consumers increasingly demand save and healthy food of high quality. At Særheim Research Centre, effects of environmental conditions (light, temperature, CO2, air humidity, nutrients, growth media) and cultural practices (training, irrigation, harvesting) on size, colour, shelf life, taste and biochemical compounds are being quantified. It could be shown how light intensity and light quality effects the contents of chlorophyll, anthocyanins, ascorbic acid and nitrate in lettuce, shelf life and taste in herbs, taste and antioxidant activity in strawberry, titratable acidity and the contents of phenolics, ascorbic acid, lycopene and soluble solids in tomato. Results will be presented at the workshop. The favourable ratio between light and temperature in our region offers an opportunity to produce high quality products year-round. Norway is known as a healthy country, with little problems with pests and diseases, with an availability of renewable energy, organic growth media and organic fertiliser and with a high water quality. This gives rise to a development of organic production. Research on organic production of greenhouse vegetables started at Særheim in 2003. By now, a rational growing system for organic production of tomato is developed and a system for cucumber production is on trial. Preliminary trials show differences in the content of phenolic compounds, ascorbic acids and antioxidant activity in fruits and plants grown on organic growth media when compared to rockwool. Results will be presented at the workshop.

Sammendrag

Forsøkene undersøkte virkningen av vekstduk og mulchtype på avling og kvalitetskomponenter i `Korona" jordbær ved dyrking i tunnel i to år. Tunnelen førte til redusert innstråling (PAR), særlig i det andre avlingsåret, og enkelte dager så mye at det ville ha negativ effekt på avling. Vekstduk reduserte fruktstørrelse og avlinge i det første året, mens hvit mulch ikke hadde noen klar effekt på totalavling. Imidlertid ga hvit mulch større frukter enn brun mulch i det første avlingsåret, og en større andel frukter større enn 25 mm i begge årene. Når bladverket var utvokst ble temperaturen i plantebestanden høyere over hvit enn over brun plastfoliemulch på dager med sterk innstråling og %RF ble samtidig kraftig redusert. Temperaturen under vekstduken ble betydelig høyere enn uten vekstduk, og i det første året så høy at plantene ble utsatt for varmestress. I begge årene økte klorofyllinnholdet i bladene ved dyrking på hvit sammenlignet med brun folie. I det første året ga vekstduk økt klorofyllinnhold, mens forholdet var motsatt i det andre året. Fruktkvaliteten ble påvirket både av fruktorden, mulchtype og vekstduk.

Sammendrag

The content of selected plant constituents was measured in cherry tomatoes (Lycopersicon esculentum Mill. cv Jennita) during conventional Norwegian tomato production in a greenhouse from May until October 2004. Samples were collected according to standard production procedure with orange-yellow coloured fruits at weight in the range of 12.4 -19.3 g and size in the range of 28.9-33.0 mm (diameter). The content of selected compounds based on 100 g FW were found to vary in the following range during the season: 7.38-28.38 mg chalconaringenin, 0.32-0.92 mg rutin, 0.24-1.06 mg chlorogenic acid, 5.60-20.02 mg ascorbic acid, 1.60-5.54 mg lycopene and 0.37-0.55 mg b-carotene. Only minute amounts of naringenin together with kaempferol 3-rutinoside and caffeic acid, which previously have been reported from tomatoes, were detected. The content of chalconaringenin to rutin, and that of lycopene to b-carotene showed a strong correlation during the season (p < 0.001). The content of total phenolics and methanol soluble antioxidants also showed a correlation (p < 0.001), and were found in the range 14.6 - 32.6 mg GAE/100 g FW and 445 - 737 mmol FeII/100 g FW, respectively. Seasonal variation in the level of plant constituents is shown to be related to photon flux density and fertilization level.

Sammendrag

Resultatene bekrefter den dominerende rollen til genotype for danning av fenoler. Det ble også vist at virkningen av omgivelsene var påvirket av genptype. Av andre faktorer påvirket nitrogen fenolene mest. Resultatene foreslår at foredling er en måte å øke innholdet av fenoler på. Imidlertid, foredling tar tid og produktet er tilpasset bare for et spesifikt miljø. Siden det blir konsumert relativt mye bær, kan kunnskap om faktorer som bare har liten virkning på innholdet av fenoler ha en stor betydning for inntaket av disse.

Sammendrag

The Norwegian government aims that ten percent of the total agricultural area must be grown ecologically by 2010. A further goal is that ecologically grown vegetables should cover 15 % of the market. In spite of earlier efforts, the production and sale of ecological vegetables is still on a very low level. Successful production of organic greenhouse vegetables requires a good knowledge of both organic principles and effective greenhouse production. In order to increase the marketable yield, agronomical problems concerning the transition from conventional to organic greenhouse production should be solved. The main challenge in this sense is the proper use of organic growing media and fertilisers. In 2003, Planteforsk Særheim Research Centre started a trial to develop a growing concept for ecologically grown greenhouse tomatoes following the standards set up by the Norwegian Food Safety Authority and controlled by "Debio". In order to avoid problems with soil borne pests and diseases and to reduce the risk of losses of plant nutrients, plants were grown in limited beds. This system gave good results in earlier experiments in Sweden (Gäredal and Lundegårdh, 1998) and might quicken the transition from conventional to ecologic production. Growing media used in the trail were peat, a mixture of peat and bark or a mixture of soil and straw with a volume of 25 or 75 litres per m2. Some of the treatments received a basic fertiliser, consisting of composted chicken or pig manure, while other treatments received no basic fertiliser. In order to meet the nutritional requirements of the plants, organic fertiliser was given regularly during the growing season. A solution of organic nutrients using drip irrigation or the coarse fraction of cattle manure applied three times a week was used. In a control treatment, plants were grown on peat bags with a volume of 25 litres per m2 and fertilised with conventional mineral nutrition. Tomato transplants were planted in week 10 and harvested until week 44. Input and output of nutrients were recorded. Results showed great differences in marketable yield between the different treatments. Plants grown in peat with a volume of 25 litres and only given a solution of organic nutrients gave a low yield (26 kg/m2) and problems with blossom end rot (33 %). Low volume hampered a proper supply of organic fertilisers. Plants grown on 75 litres of a mixture of peat and bark or a mixture of soil and straw, including compost and fertilised with cattle manure, gave a yield of 39 and 37 kg/m2 respectively. Control plants yielded 39 kg/m2. This shows that a normal yield can be achieved using organic growing media and fertilisers. In 2004 the growing concept will be further developed. It is also planned to develop a growing system for organic cucumber and lettuce production.

Sammendrag

Stadig større mjøldoggproblemer i de siste årene har økt interessen for tolerante sorter. Høsten 2002 ble fem nye tolerante sorter sammenlignet med målesorten "Indira" i paraplykultur med bruk av kunstig lys. Resultatene viser at "Indira" fortsatt er et sikkert sortsvalg. Vektlegges holdbarhet, kan "Aviance" prøves.

Sammendrag

Planteforsk Særheim forskingssenter startet i år med produksjon av økologiske tomat. De første resultatene viser at avlingen blir mye høyere enn forventet.

Sammendrag

Utgangspunktet for prosjektet "sunne planter-sunnere kosthold" er påstanden om at oppal av planter i et biologisk aktiv dyrkingsmedium gir sunnere småplanter som etablerer seg raskere etter utplanting og har økt motstandsevne mot flere plantesykdommer enn småplanter alet opp i kunstige og sterile dyrkingsmedium. I tillegg skal plantenes/produktenes innhold av antioksidanter være høyere. I det foreliggende forsøket ble det sett nærmere på disse påstandene gjennom oppal og dyrking av veksthusagurk under strengt sammenlignbare, definerte og kontrollerte forhold. Forsøket ble gjennomført ved Planteforsk Særheim forskingssenter på oppdrag av BAMA/Gartnerhallen. De kjemiske analysene er gjennomført ved Matforsk og PlantChem.

Sammendrag

Fire nye klasetomatsorter ble vurdert i forhold til målesorten "Cedrico". Resultatene viser at nye sorter med bedre smak også har noen negative egenskaper.

Sammendrag

Fire nye tomatsorter til løs plukking ble vurdert i forhold til målesortene "Cedrico" og "Espero". I årets prøving ble også smaksegenskapene testet. Resultatene viser at de nye sortene har flere gode, men desverre også mindre gode egenskaper.

Sammendrag

Helårsproduksjon av jordbær i veksthus kan være et interessant produksjonsalternativ. Rapporten beskriver resultatene fra et prosjekt med mål å utvikle en effektiv norsk veksthusproduksjon av jordbær av høy kvalitet. Forsøkene gjennomførtt på Planteforsk Særheim forskingssenter i perioden februar 1998 til mai 2000 viser et produksjonssystem hvor store jordbær med god smak kan produseres til enhver ønskelig tid, selv midt på vinteren. Krav til småplantekvalitet og styring av klimaforholdene i veksthus ble undersøkt og diskutert.

Sammendrag

Heving av pH i kommunalt vann i stadig flere kommuner fører til at behovet for pH-regulering øker. Vanlig praksis har vært å bruke fosforsyre eller salpetersyre. Forsøk ved Planteforsk viser at også CO2 kan brukes. Tilføring av CO2 i råvannet reduserte pH og økte bikarbonatinnholdet i næringsløsningen. Det ble ikke funnet forskjeller i tilvekst av ulike kulturer når råvann med lav bikarbonattall ble regulert ved hjelp av syre eller CO2.

Sammendrag

Prosjektets hovedmål er til å dokumentere virkningen av noen dyrkingsforhold, høstetidspunkt og behandling etter høsting på tomatkvalitetet. Resultater fra forsøket viser at dyrkings- og lageringsforholdene har en målbar effekt på tomatkvaliteten. Kvalitetsikring av norske tomater krever tilgang til objektive målings-metoder. Særlig ved markedsføring av norske "smaks-tomater" er det viktig at smaken lettvint og rutinemessig kan kontrolleres.

Sammendrag

Melduggproblemer stadig tidligere i sesongen gjør det vanskeligere å velge den rette sorten. Fire nye halvtolerante sorter og en ny ikke tolerant sort ble vurdert i forhold til "Jessica" i en paraplykultur tidlig om våren. Resultatene viser at både den halvtolerante sorten "Aviance" og den ikke tolerante "RZ 24-108" er et bedre valg enn "Jessica".

Sammendrag

Bruk av kunstig lys med høy belysningsstyrke kan være en måte å produsere jordbær uavhengig av sesonger i Norge. For å undersøke produksjons mulighetene, ble et fosøk utført om vinter med å dyrke planter i 12 uker under kunstig lys. Resultater viser maksimale produksjon på 4,4 kg. pr. m2 ved 12,7 planter pr. m2. Plantekvalitet viser seg å være avgjørende for en økonomisk produksjon. Resultater fra dette forsøk blir brukt til å utarbeide metoder for helårs produksjon.

Sammendrag

Bruk av mjøldoggtolerante sorter er en av de mulighetene vi har til å hindre de stadig økende problemer med mjøldogg i agurk. Fem nye mjøldoggtolerante sorter ble vurdert i forhold til målesorten `Indira` i et høsthold med nedsenking og bruk av kunstig lys. Det viste seg at de nye sortene ikke nødvendigvis er noe bedre alternativ enn de vi til vanlig bruker.

Sammendrag

Fire nye tomatsorter ble vurdert i forhold til målesortene "Aromata" og "Espero". Resultatene viser at "Cedrico" er en lovende nykommer med god avling med faste frukt og god holdbarhet. Det ble også konstatert noen mindre positive egenskaper. Dessverre er ingen av sortene perfekte.

Sammendrag

I prosjektet "Økt produktivitet i agurk og tomat gjennom miljøvennlig plantevern og effektiv dyrkingsteknikk" har en i perioden 1997-1999 arbeidet med ulike teknikker for rensing av resirkulerende næringsløsning i veksthus

Sammendrag

Som en del av prosjektet - Produktivitets- og kvalitetsøkning i agurk og tomat" ble vannforbruk og avrenning registrert i ulike gartnerier. Resultatene viste at gartnerne har blitt mer oppmerksommme på vanningen. Tomatgartneriene som var med i prosjektet har klart å redusere avrenningen til 20 prosent

Sammendrag

Praksis har vist at riktig vanning kan være svart så vanskelig. I et forsøk på å gjøre vanningen bedre er det gjennomført en registrering av plantenes daglig vannforbruk og på bakgrunn av dette utviklet enklet regler for vanntilførsel. Arbeidet er gjennomført av Planteforsk Særheim forskingssenter.

Sammendrag

Fem nye agurksorter ble sammenlignet med standardsorten "Ventura" i et vinterhold med bruk av kunstig lys. To av sortene, "Nova" og "Euphoria", viste seg å være bedre alternativer, både når det gjelder avling og kvalitet.

Sammendrag

Helårsproduksjon av tomat ved hjelp av kunstig lys lar seg gjennomføre, både teknisk og økonomisk. Dette sier en prosjektgruppe i Nederland, bestående av dyrkere, forskere og representanter fra næringslivet. Resultatene fra et prøveprosjekt er så lovende at det snakkes om en ny revolusjon i tomatproduksjonen.

Sammendrag

Analyser av enggras på Jæren i dette året viste at fordøyeligheten gikk fort ned p.g.a. høye temperaturer. Gode vekstforhold framkalte rask nedgang også i proteininnhold. Trevlerinnholdet var høyt, spesielt i timotei. Analyseresultatene blir brukt til å utvikle en beregningsmetode for veiledere og bønder til å forutse fôrkvaliteten på den enkelte gård ut fra opplysninger om jord- og værforhold. Det åpnes dermed bedre muligheter til å tilpasse høstetiden til dyras behov.