Hopp til hovedinnholdet

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.

2021

To document

Abstract

The natural light conditions above the Arctic Circle are unique in terms of annual variation creating special growth conditions for crop production. These include low solar elevations, very long daily photosynthetic light periods, midnight sun/absence of dark nights, and altered spectral distribution depending on solar elevation. All these factors are known to affect the growth and the metabolism of plants, although their influence on northern crop plants has not yet been reviewed. The ongoing global warming is especially affecting the temperature × light interactions in the Arctic, and understanding the impact on crop production and plant metabolism will be important for an Arctic contribution to global food production. Arctic light conditions have a strong influence on the timing of plant development, which together with temperature limits the number of cultivars suitable for Arctic agriculture. This review compiles information from the reports about the effects of light conditions at high latitudes on growth, biomass production, flowering and quality of the crop plants and discusses the gained knowledge and the key gaps to be addressed.

To document

Abstract

Several factors may define storability in root crops. In the following paper, preliminary results are presented from two experiments performed to test factors affecting storage quality of carrot. The study have focused on 1) soil loosening/soil compaction and 2) different cultivars of carrot and root age considered by the length of the growing period. The results so far indicate that the soil compaction had few effects on storability of carrot, but did seem to negatively affect the length of the carrot. Soil loosening reduced the occurrence of liquorice rot caused by Mycocentrospora acerina. Large differences were found in storability between the ten tested carrot cultivars and length of growing period tended to be negatively correlated to storability. We conclude that a number of precautions in carrot production may increase storability and thus economic performance.

Abstract

The use of peat as a growing media in horticulture is supposed to be reduced due to negative effects of its production on the environment. Interest in development of alternative growing media is therefore increasing and is enhanced by both political pressure and industry demands. Therefore, the influence of 33 growing media on the performance and productivity of two strawberry cultivars were examined in a polytunnel under Nordic conditions (60.7 N). Alternative substrates including fibers of spruce, birch and flax and coffee grounds were tested standalone or in mixes. Peat and coir were included as controls. Additionally, impregnation of the wood fibers with organic and inorganic substances was examined. All investigated growing media received identical fertigation strategies (EC 1.5). The highest average biomass production was observed for plants grown in bare peat; however, the best yield performance was noted for peat mixed with perlite and for coarse spruce fiber. Strawberries grown in these two best performing substrates showed comparable overall productivity, with 272 and 268 g of berries per plant, respectively. Both peat/perlite mix and the coarse spruce fiber had also a similar weight of berries larger than 25 mm, with 210 and 198 g plant-1, respectively. Moreover, improvement of the substrate structure by adding perlite or wood chips may have had a pronounced effect on fruiting performance. When compared to peat with added perlite (which gave the highest berry yield in the experiment; 272 g plant-1), strawberries grown in pure peat produced only 187 g plant-1. Furthermore, impregnation of spruce fiber with humic acid enhanced fruiting performance by increasing the total yield and number of large berries (≥25 mm). Future prospects for this study include establishment of an optimal structure of spruce fiber substrate suitable for strawberry production and development of the fertigation strategy optimized for the new growing media.

Abstract

Hydroponic production of strawberry (Fragaria × ananassa Duch.) in protected cultivation systems using substrates (growing media) is gaining popularity worldwide. Therefore, it is necessary to develop more sustainable growing media alternatives. This study focused on growth performance of strawberry plants grown in wood fibre from Norway spruce (Picea abies (L.) H. Karst.), in comparison to two industry standards (peat and coco fibres). Plug (tray) plants of the June-bearing strawberry cultivar 'Malling Centenary' and bare root (WBH) plants of cultivar 'Sonata' were transplanted into three different growing media: peat (80%) and perlite (20%) mixture, coconut coir (100%) and Norway spruce wood fibre (100%). The plants received four fertigation strategies (various potassium and nitrogen concentrations) from flowering onwards. Throughout the production season ripe berries were harvested and frozen for later analyses of chemical composition. Plant architecture was also recorded after termination of the experiment. The results revealed that the most significant differences among the majority of the fruit and plant parameters were due to cultivar traits. Strawberries grown in wood fibre produced slightly smaller berries with elevated °Brix and dry matter compared to berries from plants grown in peat and coir. This was most likely caused by the common fertigation strategy applied to all substrates. Nevertheless, among the tested fertigation strategies, application of solutions with elevated potassium resulted in the highest sugar accumulation in berries grown in wood fibre substrate. In general, the experiment revealed relatively negligible differences between the growing media, and we therefore conclude that wood fibre from Norway spruce may be a viable alternative as a growing media in hydroponic strawberry production when the fertigation strategy is precisely adjusted.

To document

Abstract

Impact of orchard management technologies on apple fruit internal quality was tested in several trials performed at the Institute of Horticulture, Lithuanian Research Center for Agriculture and Forestry during 2010-2019. Studies were focused mainly on the research of bioactive compounds: triterpenes and phenols. Studies included rootstocks, crop load regulation, planting distances, fruit position in the tree crown, geographical locations, regulation of tree vegetative growth by root pruning, trunk incision and prohexadione-calcium. ‘Auksis’ apple fruits on P 67 rootstock and ‘Ligol’ on P 61 and P 22 had the highest total phenol content, while the lowest total phenol content of both tested cultivars was recorded on M.9 and P 62 rootstocks. Increasing crop load on the tree led to significant increase of phenols and triterpenes. Higher fruit triterpene concentration was recorded on denser planted trees. Root pruning increased accumulation of phenols, while by the application of prohexadione-calcium the accumulation of phenols decreased significantly. Lower triterpene concentration was recorded when tree growth was controlled by trunk incision. Fruits from the top of the tree accumulated significantly higher amount of phenolic compounds, whereas fruits inside the tree crown were characterized by the highest amount of triterpene compounds. Colder climate during the vegetation and shorter vegetation period resulted in significantly higher accumulation of phenolic and triterpene compounds in apples grown in Estonia comparing to fruits grown in Poland. New scientific results on the impact of modern technologies on the changes of internal fruit quality parameters could increase consumption of apples.

To document

Abstract

The circular economy concept promotes the recycling of agricultural waste. This study was aimed at investigating the effects of cattle horn shavings on apple tree nitrogen nutrition. Ligol apple trees on P 60 rootstock were the object of the study. The experiment was conducted in the experimental orchard of the Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry, from 2015 to 2018. Two fertiliser rates were tested: 50 and 100 kg/ha N. Horn shavings (14.1% N) were applied at the end of autumn or at the beginning of vegetation in the spring and in one treatment 100 kg/ha N rate was divided into two equal parts and applied both in autumn and spring. The effects of the horn shavings were compared with the effects of ammonium nitrate (34.4% N) and the unfertilised treatment. The lowest mineral nitrogen content was found in the unfertilised orchard soil and the soil fertilised with horn shavings in the spring at 50 kg/ha N equivalent. In all other cases, the fertilisers increased the soil’s mineral nitrogen content. The lowest leaf nitrogen content was found in apple trees that grew in the unfertilised orchard soil or soil fertilised in the spring with 50 kg/ha N of horn shavings (1.58–2.13%). In other cases, leaf nitrogen content was higher (1.77–2.17%). The apple trees with the lowest leaf nitrogen content produced the smallest average yield (34.5–36.6 t/ha). The highest yield was recorded from fruit trees fertilised with 50 kg/ha N of ammonium nitrate applied in spring or horn shavings applied in autumn (42.4 and 41.4 t/ha, respectively). The influence of horn shavings on the other studied parameters was similar to that of ammonium nitrate. Horn shavings, like nitrogen fertiliser, could facilitate nitrogen nutrition management in apple trees, especially in organic orchards, where the use of synthetic fertilisers is prohibited.