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Publications

NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.

2023

Abstract

Global warming benefits enrichment of the assortment of cultivated fruit trees. New fruit species, less winter hardy, demanding higher temperatures during their growth and longer vegetation period, could become new commercial crops in Norwegian orchards. Up to now there is a lack of knowledge and experience with new fruit species in Norway. Main goal of the project was to justify the possibilities of introduction of new fruit crops namely table/wine grapes, peaches, apricots, and nectarines. The project implementation was based on literature analysis, questionnaires of growers and scientists, information gathered during the visits to scientific institutions and farmers in Norway, Sweden, Latvia, and Lithuania. According to growers’ experience and research performed in Norway, neighbouring countries and in regions with similar climate, a number of wine grape and apricot cultivars can be successfully grown in Norway. However, table grapes, peach and especially nectarine are more risky crops. After comprehensive analysis of cultivar characteristics and management, recommendations for the introduction of new cultivars were prepared for commercial growing or additional cultivar evaluation trials.

Abstract

This report presents results of two plum cultivars and selections trials, performed during 2013-2021 and 2016-2021 at Ullensvang. In total, 19 plum cultivars were evaluated: 4 from the Institute of Horticulture, Čačak, Serbia; 9 cultivars and selections bred by Einar Ruud, Søgne; 3 plum selections from Graminor, Njøs and 1 cultivar from NMBU. Cultivars Opal and Čačanska lepotica served as control. The aim of these reported plum cultivar trials was to investigate recently released plum cultivars and premium selections from Norwegian and Serbian breeding programs from pomological, agronomical, and biochemical point of view, identify the most important quality parameters, and select cultivars with desirable traits for the modern market in Norway. Based on overall fruit quality and tree productivity, selections NPr. 458 and Anne (R21) (Rudiplomme, if a DNA-test reveal that it is the same as the cultivar Anne (R 21)) are selected for fresh consumption and can be recommended for further commercial growing tests. Due to very sweet and good fruit taste, cultivars Boranka and Ellen might be used for jam.

Abstract

There is an increased interest in the hydroponic production of strawberries in protected cultivation systems, and it is, therefore, urgent to develop new, more sustainable growing media alternatives. This study investigated the physical properties of wood fiber produced from Norway spruce (Picea abies (L.) H. Karst.) and peat:wood fiber substrate blends as well as the performance of the wood fiber in comparison to the industry standards, i.e., peat and coconut coir in the cultivation of hydroponic strawberry. Tray plants of the June-bearing strawberry (Fragaria × ananassa Duch.) cultivar ‘Malling Centenary’ were transplanted into five different growing media: a peat (80%) and perlite (20%) mixture, stand-alone (100%) coconut coir and three stand-alone (100%) Norway spruce wood fiber substrates (including coarse textured fibers with compact and loose packing density and compacted fine-textured fibers). Ripe strawberries were harvested and registered throughout the production season. The overall marketable yield was comparable across all the tested growing media; however, after 4 weeks of harvest, both coarse wood fiber and fine wood fiber showed better fruiting performance than the peat-perlite mixture. A trend for earlier berry maturation was observed for all wood fiber-based substrates. Plant parameters recorded after the end of production showed that plant height, number of leaves, and biomass production were higher in coarse wood fiber than in the peat-perlite mixture. Moreover, plants grown in wood fiber-based substrates had less unripe berries and flowers not harvested in comparison to both the peat and coir treatments.

To document

Abstract

There is a stable growth in aquaculture production to avoid seafood scarcity. The usage of eco-friendly feed additives is not only associated with aquatic animal health but also reduces the risk of deleterious effects to the environment and consumers. Aquaculture researchers are seeking dietary solutions to improve the growth performance and yield of target organisms. A wide range of naturally derived compounds such as probiotics, prebiotics, synbiotics, complex carbohydrates, nutritional factors, herbs, hormones, vitamins, and cytokines was utilized as immunostimulants in aquaculture. The use of polysaccharides derived from natural resources, such as alginate, agar, laminarin, carrageenan, fucoidan, chitin, and chitosan, as supplementary feed in aquaculture species has been reported. Polysaccharides are prebiotic substances which are enhancing the immunity, disease resistance and growth of aquatic animals. Further, chitin (CT), chitosan (CTS) and chitooligosaccharides (COS) were recognized for their biodegradable properties and unique biological functions. The dietary effects of CT, CTS and COS at different inclusion levels on growth performance, immune response and gut microbiota in aquaculture species has been reviewed. The safety regulations, challenges and future outlooks of CT, CTS and COS in aquatic animals have been discussed in this review.

To document

Abstract

To compensate for higher production costs in winter, tomato cultivars with better taste and flavor characteristics and higher selling price are often cultivated. Tomato taste and flavor is reduced during cold storage, however the reduction is often cultivar dependent. Little is known how postharvest storage conditions affect flavor and taste quality of tomatoes cultivated in greenhouses during wintertime at high latitudes. This study was aimed to analyze how postharvest storage conditions affect composition of flavor-related volatile organic compounds (VOCs) and taste quality of tomato fruits. Tomato cultivars ‘Brioso’, ‘Flavance’, ‘Piccolo’, ‘Sweetelle’, ‘Sweeterno’ were grown in greenhouses with artificial lightning in southwestern Norway during wintertime and were collected ripe. Experimental set up was simulating shortest postharvest chain for southwestern Norway, including harvest day (18°C for one day, in darkness), packaging and transport (12°C for 3 days, in darkness), retail (18°C for 2 days, with light) and consumer storage in either a refrigerator (4°C for 4 days, in darkness) or a kitchen counter (20°C for 4 days, with light). VOC composition of tomato fruits was analyzed using HS-SPME-GC-MS. Fruit quality parameters including sugars, titratable acidity (TA), dry matter content, firmness and pigments were analyzed. Laboratory results were compared to responses from a taste panel. Firmness and TA were lower for fruits after storage at both conditions compared to fresh fruits. Relative concentrations of the most flavor-related VOCs were lowest for fruits after storage at both conditions. The reduction was higher when fruits were stored at 4°C. Fruits from cultivars ‘Sweeterno’ and ‘Piccolo’ showed the lowest difference in relative VOC concentration at 4°C. Perceived overall tomato taste generally decreased after storage. Overall, storage at 20°C is favorable for preserving flavor of most winter-produced tomato cultivars, but disadvantageous for maintaining their firmness and TA.

Abstract

Appropriate weed control measures during the renewal phase of temporary grasslands are critical to ensure high yields during the whole grassland lifecycle. The aim of this study was to determine which integrated grassland renewal strategy can most effectively control annual weeds in the sowing year and delay perennial weed re-establishment. Four split-plot trials were established at three sites dominated by Rumex spp. along a south-north gradient in Norway. The annual and perennial weed abundance was recorded during the sowing year and two or three production years. Main plots tested seven renewal strategies: 1. Spring plowing, 2. Spring plowing+companion crop (CC), 3. Summer cut+plowing, 4. Summer glyphosate+plowing, 5. Summer glyphosate+harrowing, 6. Late spring glyphosate+plowing, 7. Fall glyphosate+spring plowing+CC. Strategies 1–4 were tested in all four trials, strategy 5 in three trials, strategy 6 in two trials and strategy 7 in one trial. Plowing was performed at 20–25 cm depth, rotary harrowing at 15 cm depth, and glyphosate was applied at 2160 g a.i. ha-1. CC was spring barley (Hordeum vulgare). Subplots tested selective herbicide spraying (yes/no) in the sowing year. Results showed that effects of renewal strategies were often site-specific and differed between the sowing year and production years. Spring renewal resulted in higher perennial weed abundance than summer renewal in two out of four trials (by 3 and 12 percentage points, over all production years), and glyphosate followed by harrowing drastically increased Rumex spp. in one out of three trials (by 18 percentage points over all production years). CCs only significantly reduced perennial weed abundance in one trial (by 8 percentage points over all production years). In comparison, the selective herbicides had a strong effect on annual and perennial weeds in the sowing year in all trials. Selective herbicides reduced the weed cover from 32% to 7% cover, and averaged over the production years and sites, the perennial weed biomass fraction was 6 percentage points lower where herbicides had been applied. We conclude that while the tested renewal strategies provided variable and site-specific perennial weed control, selective herbicides were effective at controlling Rumex spp. and other perennial dicot weeds in the first two production years.