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.
2024
Authors
Maurine Oluchukwu OkolieAbstract
This study examines the potential of large-scale urine recycling as a sustainable solution to address sanitation challenges, enhance agricultural productivity, and improve food security in Bahir-Dar, Ethiopia. The approach involves establishing urine recycling systems (URS) that collect urine from onsite sanitation facilities and convert it to dry urine-based fertilizer (UBF) near collection sites for local farmers. Using a combination of primary and secondary data sources, this study performs a cost-benefit analysis (CBA) to evaluate the financial viability of implementing URS in Bahir Dar, focusing on direct monetary costs and benefits. The assessment includes metrics such as net present value (NPV), internal rate of return (IRR), benefit-cost ratio (BCR), and payback period (PBP) and is supplemented by sensitivity and scenario analyses to account for varying assumptions. The findings reveal that, under the set assumptions of this study, implementing urine recycling systems is not financially viable in Bahir Dar. The financial feasibility is highly dependent on the capacity of the urine recycling technology and the fees charged for using the toilet facilities. Higher dehydration capacity significantly improves financial outcomes, as does charging users for each use of the facilities. Charging higher fees per use enhances the economic viability of the system. Based on these findings, the study recommends further research on integrating indirect benefits, which include social and environmental benefits. This will provide a comprehensive understanding of the value of the urine recycling system.
Abstract
No abstract has been registered
Authors
Anne MartinussenAbstract
The goal of this thesis was to enhance the effectiveness of the conservation of the potato in vitro bank, by finding more efficient ways to maintain the bank and to introduce new varieties. A different method for virus detection was examined (Recombinase Polymerase Amplification on potato skin cDNA samples), slow growth mediums were tested on different potato varieties, and meristem culturing was carried out to eradicate viruses from infected plant material. First, an initial slow growth test experiment with ten potato varieties was executed. Apical and axillary shoot cuttings were subjected to mediums with 0 mg/L, 0,5 mg/L, 1 mg/L, 3 mg/L or 5 mg/L Abscisic acid (ABA). The apical shoot cuttings had a lower survival rate. The ABA successfully reduced growth, but the high ABA mediums (3 mg/L and 5 mg/L ABA) had a lower survival rate. After nine months on the mediums the survival rate was higher on the 3 mg/L and 5 mg/L ABA mediums. Second, a bigger slow growth experiment was done including ten potato varieties and 12 different mediums. The mediums both varied in sucrose and ABA concentration. The experiment showed that sucrose and ABA both stunt the growth of potatoes in vitro. The medium with the best characteristics seemed to be 3% sucrose and 1 mg/L ABA, as this medium gave no abnormal growth (contrary to what is seen on the high sucrose mediums), no fall in early survival (compared to what was seen on high ABA medium), low variance in growth between varieties (compared to the other sucrose treatments) and gave considerable growth reduction. This medium would allow the varieties to be transferred to a new medium after more than four months in the potato in vitro bank, lessening the work needed to maintain the potato in vitro bank. Four virus-infected varieties were meristem cultivated to virus free material. Only one of these, Blåpotet, was completely cleaned of viruses. The potato virus Y (PVY) (Species Potato virus Y, genus Potyvirus, Family Potyviridae) was cleaned from Kvit Rund Kvam. Åkerøy was not successfully cleaned for viruses, but some meristems survived and grew into plants. Only the shoot tip in vitro cultures of Early Rose survived. Primers were designed to test for PVY using Recombinase Polymerase amplification (RPA). Three different primer pairs were tested; “PVY1” which used primers from two different papers (Cassedy et al., 2022; Y. Wang et al., 2020), “PVY2” from a paper by Ying Wang and Ruhao Chen (Y. Wang et al., 2020), and “PVY3”, a primer pair designed by me. The primer pair that gave the least extra bands and streaks of nucleic acid when visualized on gel was PVY1. The RNA samples extracted from Potato skins were however of too low quality to be used for regular PVY testing. Better sampling of potato skins and improvement of the RNA extraction is needed. RPA on potato skin cDNA samples cannot be reliably used for virus testing, until the protocol is changed. This could be done by using a RNA extraction kit optimized for tuber samples.
Abstract
In Norway, there is political goal to increase the degree of self-sufficiency of fruits. To achieve this goal, the sales period of Norwegian produced apple fruit needs to be extended, and thus, the storage technology improved. Sensory quality is of importance for consumers acceptability of the apple fruit. The aim of this study was to evaluate the sensory properties of the apple cultivars ‘Red Elstar’ and ‘Rubinstep’ treated with 1-methylcyclopropene (1-MCP) in combination with storage in regular and controlled atmosphere. Before storage, the harvested fruit were divided into two parts; half treated with 1-MCP and the other half untreated. A semi-trained sensory panel evaluated selected sensory properties of apple fruit harvested in 2021, 2022, and 2023, and stored in regular or controlled atmosphere at 2°C for 5.5, 5.5, and 4 months, respectively. Treatment with 1-MCP in combination with controlled atmosphere storage resulted in the highest sensory score of firmness, crispiness, and juiciness, and lowest score for mealiness and sweetness. Fruit stored in a regular atmosphere without 1-MCP had less acidity and the fruitiest aroma. How to obtain optimal taste of ‘Rubinstep’ and ‘Red Elstar’ after the different post-harvest treatments will be discussed.
Abstract
In Norway, the apple cultivar ‘Red Aroma’ accounts for approximately one third of the Norwegian production. Treatment with 1-MCP has been tested on fruit of different ripening degrees to improve shelf-life and sensory properties. Fruits were harvested and treated with 1-MCP at one-week intervals starting two weeks before optimal harvest time (OHT) and ending two weeks after OHT. Fruits were stored until the end of November in regular atmosphere at 4 °C. A semi-trained sensory panel evaluated selected sensory parameters in addition to measurements of physiochemical parameters using traditional methods. The panel evaluated 1-MCP treated fruit from all harvest times as more acidic, firmer, less mealy, crisper, and juicier than the untreated fruit. The untreated fruit harvested one or two weeks after OHT were more aromatic (floral and fruity aroma), sweeter, and riper. Intensity of grassy flavour was lowest for the untreated fruit after the optimal harvest time. Some of the evaluated sensory properties correlated with measured physiochemical parameters. Optimal sensory quality in relation to harvest time and 1-MCP treatment will be discussed.
Authors
May Bente BrurbergAbstract
No abstract has been registered
Authors
Begum BilgicAbstract
No abstract has been registered
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No abstract has been registered