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.
2025
Authors
Alexey Mikaberidze C. D. Cruz Ayalsew Zerihun Abel Barreto Pieter Beck Rocío Calderón Carlos Camino Rebecca E. Campbell Stephanie Delalieux Frederic Fabre Elin Falla Stuart Fraser Kaitlin Gold Carlos Gongora-Canul Frédéric Hamelin Dalphy Ondine Camira Harteveld Cheng-Fang Hong Melen Leclerc Da-Young Lee Murillo Lobo Jr Anne-Katrin Mahlein Emily McLay Paul Melloy Stephen Parnell Uwe Rascher Jack Rich Irene Salotti Samuel Soubeyrand Susan Sprague Antony Surano Sandhya Takooree Thomas H. Taylor Suzanne Touzeau Pablo Zarco-Tejada Nik CunniffeAbstract
Plant diseases impair the yield and quality of crops and threaten the health of natural plant communities. Epidemiological models can predict disease and inform management. However, data are scarce, because traditional methods to measure plant diseases are resource intensive, which often limits model performance. Optical sensing offers a methodology to acquire detailed data on plant diseases across various spatial and temporal scales. Key technologies include multispectral, hyperspectral, and thermal imaging, as well as light detection and ranging; the associated sensors can be installed on ground-based platforms, uncrewed aerial vehicles, airplanes, and satellites. However, despite enormous potential for synergy, optical sensing and epidemiological modeling have rarely been integrated. To address this gap, we first review the state of the art to develop a common language accessible to both research communities. We then explore the opportunities and challenges in combining optical sensing with epidemiological modeling. We discuss how optical sensing can inform epidemiological modeling by improving model selection and parameterization and providing accurate maps of host plants. Epidemiological modeling can inform optical sensing by boosting measurement accuracy, improving data interpretation, and optimizing sensor deployment. We consider outstanding challenges in (A) identifying particular diseases; (B) data availability, quality, and resolution; (C) linking optical sensing and epidemiological modeling; and (D) emerging diseases. We conclude with recommendations to motivate and shape research and practice in both fields. Among other suggestions, we propose standardizing methods and protocols for optical sensing of plant health and developing open access databases including both optical sensing data and epidemiological models to foster cross-disciplinary work.
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Authors
Marte Persdatter Tangvik May Bente Brurberg Christer Magnusson Arne Stensvand Simeon RossmannAbstract
Metabarcoding targeting nematodes, bacteria, fungi and oomycetes was used in combination with multispectral drone imagery and traditional soil extraction of nematodes to diagnose poor growth in patches of a potato field in Norway. Areas of good and poor growth as identified by the normalised difference vegetation index (NDVI) based on aerial photography were compared, and nematodes were identified as the likely drivers of poor growth. This was based on the presence of known plant-parasitic nematodes in the field and the significant association between low alpha diversity (total genus richness and abundance) for nematodes with areas of poor growth, while alpha diversity for other organism groups did not vary between patches with good and poor growth. Metabarcoding represented nematodes well compared to traditional soil extraction. The combination of aerial photography and metabarcoding used in this work offers a promising possibility to identify biological drivers of growth differences across organism groups at field scale.
Abstract
Bacterial canker caused by Pseudomonas syringae is an important disease on stone fruit trees. The development of infections after artificial inoculation of sweet cherry and plum trees in the nursery phase was examined. Furthermore, sweet cherry trees were observed in a nursery and for up to four years after planting in commercial sweet cherry orchards. If inoculated at the time of grafting, this caused near 100% death of the scions. Following inoculation of defeathering wounds, a mean of 52 and 61% of inoculation sites developed bacterial canker on sweet cherry and plum, respectively. Of non-inoculated nursery trees observed as healthy in the autumn, between 20 and 80% had developed visible bacterial cankers after a period of cold storage. In the planting year, a mean of 21% of the trees developed bacterial canker in seven commercial orchards included in the investigation, and by 2–4 years after planting 40% of the trees had symptoms of the disease. All sweet cherry cultivars and rootstocks developed bacterial canker in the commercial orchards. Cultivar Giorgia had the most severe symptoms. Up to 60% replacement of trees within two years after planting was experienced in the orchards.
Abstract
European canker developing in young apple orchards may have been initiated in the nursery. Artifcial inoculation of Neonectria ditissima was carried out at time of heading back and manipulating of branch angles in the second year of nursery phase sized trees of 10 apple cultivars, either T-budded or grafted (with or without interstem). The trees were followed for two growing seasons and canker was found on 10% of the trees inoculated in wounds from heading back of the top shoots and on 24% of the trees inoculated in cracks from bending side branches. About 50% of those trees had visible cankers after the frst growing season, clearly showing the risk of delivering non-symptomatic trees to customers when infected in year two of the nursery phase. Commercial trees of six cultivars were inoculated either in wounds (cut surfaces or cracks from bending), or on nonwounded trees at the time of planting and followed for two growing seasons. Inoculation in crack wounds from bending side branches resulted in a higher number of infected trees than cut surfaces, and both had a signifcantly higher incidence than non-wounded inoculated trees and their non-inoculated controls (97%, 67%, 14%, and 3 to 5%, respectively). All trees with canker after two growing seasons had symptoms after the frst growing season. After two growing seasons, 50% of the trees with an infected scion had canker lesions on the rootstock. These results show that cankers discovered during the year of planting could have been newly initiated infections if the trees had been wounded and exposed to inoculum at planting.
Authors
H. Heinemann F. Durand-Maniclas F. Seidel F. Ciulla Teresa Gómez de la Bárcena M. Camenzind S. Corrado Z. Csűrös Zs. Czakó D. Eylenbosch Andrea Ficke C. Flamm J.M. Herrera V. Horáková A. Hund F. Lüddeke F. Platz B. Poós Daniel Rasse M. da Silva-Lopes M. Toleikiene A. Veršulienė M. Visse-Mansiaux K. Yu J. Hirte A. DonAbstract
Ensuring food security through sustainable practices while reducing greenhouse gas emissions are key challenges in modern agriculture. Utilising genetic variability within a crop species to identify varieties with higher root biomass carbon (C) could help address these challenges. It is thus crucial to quantify and understand intra-specific above- and belowground performance under varying environmental conditions. The study objectives were to: (a) quantify root biomass and depth distribution in different winter wheat varieties under various pedoclimatic conditions, (b) investigate the influence of variety and pedoclimatic conditions on the relationship between above- and belowground biomass production, and (c) assess whether optimised winter wheat variety selection can lead to both greater root biomass C and yield, boosting C accrual. Root biomass, root distribution to 1 m soil depth and root-to-shoot ratios were assessed in 10 different winter wheat varieties grown at 11 experimental sites covering a European climatic gradient from Spain to Norway. Median root biomass down to 1 m depth was 1.4 ± 0.7 Mg ha−1. The primary explanatory factor was site, accounting for 60% of the variation in root biomass production, while the genetic diversity between wheat varieties explained 9.5%. Precipitation had a significantly negative effect on total root biomass, especially in subsoil. Significant differences were also observed between varieties in root-to-shoot ratios and grain yield. The difference between the variety with the lowest root biomass and the one with the highest across sites was on average 0.9 Mg ha−1 which is an increase of 45%. Pedoclimatic conditions had a greater influence than variety, and determined the relationship's direction between root biomass and grain yield. A site-specific approach is, therefore, needed to realise the full potential for increased root biomass and yield offered by optimised variety selection. Summary The variability in root biomass among 10 winter wheat varieties was quantified in field trials. Root biomass differs significantly between varieties, but is mainly driven by site conditions. Root-to-shoot ratios decreased with increasing precipitation. Root biomass was 45% higher in the best performing variety compared to the worst performing one.
Authors
Johan A. Stenberg Daniel Flø Lawrence Richard Kirkendall Anders Nielsen Selamawit Tekle Gobena Beatrix Alsanius Jorunn Børve Paal Krokene Christer Magnusson Mogens Nicolaisen Line Nybakken Iben Magrete Thomsen May-Guri Sæthre Sandra A.I. WrightAbstract
Citripar, a biological plant protection product containing the parasitic wasp Anagyrus vladimiri, is requested to be approved for use in Norway. The product is intended to be used against mealybugs, particularly Planococcus citri (citrus mealybug) and Planococcus ficus (vine mealybug) feeding on fruits, berries, vegetables and herbs in greenhouses and plastic tunnels, and on indoor plants. The Norwegian Food Safety Authority, therefore, asked the Norwegian Scientific Committee for Food and Environment to perform a risk assessment of the product. Occurrence and distribution in Norway: No observations of Anagyrus vladimiri have been reported from Norway. Potential for establishment and spread: VKM assesses that Anagyrus vladimiri will not be able to establish and spread in Norway under current conditions due to the absence of host organisms and too low winter temperatures, even in the warmest parts of the country. Potential effects on biodiversity: VKM assesses that Anagyrus vladimiri will not affect biodiversity in Norway, as there are currently no known native hosts for the wasp to parasitize. Taxonomic challenges that may affect the risk assessment: Anagyrus vladimiri belongs to the wasp family Encyrtidae, a family that includes the genus Anagyrus, many of which have quite tangled taxonomic histories. Individuals of what is now known as Anagyrus vladimiri were for many years identified as belonging to Anagyrus pseudococci. Anagyrus pseudococci and A. vladimiri are members of a complex of nearly indistinguishable species that are informally referred to as the Anagyrus pseudococci complex: A. pseudococci, A. vladimiri, A. kamali, A. dactylopii, A. kivuensis, and A. callidus. These species have been used for biological control of various mealybug species. Should incorrectly identified Anagyrus be imported to Norway, there would be no consequences for biological diversity, since the other species in the Anagyrus pseudococci complex are also host specific to mealybug genera that are not found in the Norwegian fauna, and they are physiologically unfit for the current Norwegian climate.
Abstract
Chocolate spot (CS), caused by Botrytis fabae, is one of the most destructive fungaldiseases affecting faba bean (Vicia faba L.) globally. This study evaluated 33 fababean cultivars across two locations and over 2 years to assess genetic resistance andthe effect of fungicide application on CS progression. The utility of unmanned aerialvehicle–mounted multispectral camera for disease monitoring was examined. Signif-icant variability was observed in cultivar susceptibility, with Bolivia exhibiting thehighest level of resistance and Louhi, Sampo, Vire, Merlin, Mistral, and GL Sunriseproving highly susceptible. Fungicide application significantly reduced CS severityand improved yield. Analysis of canopy spectral signatures revealed the near-infraredand red edge bands, along with enhanced vegetation index (EVI) and soil adjustedvegetation index, as most sensitive to CS infection, and they had a strong negativecorrelation with CS severity ranging from −0.51 to −0.71. In addition, EVI enabledearly disease detection in the field. Support vector machine accurately classified CSseverity into four classes (resistant, moderately resistant, moderately susceptible, andsusceptible) based on spectral data with higher accuracy after the onset of diseasecompared to later in the season (accuracy 0.75–0.90). This research underscores thevalue of integrating resistant germplasm, sound agronomic practices, and spectralmonitoring for effectively identification and managing CS disease in faba bean
2024
Authors
Emma SkogstadAbstract
In cereal production plant pathogens cause yield losses, and management strategies for controlling them are important. Cover crops as a part of the cereal production have beneficial properties for the soil health, can increase the biological diversity in the fields, and the soil structure can be improved, additionally cover crops can reduce soil erosion. Therefore, this thesis argues that implementing cruciferous plants as part of the cover crops have the potential to reduce plant pathogens. Cruciferous plants used as cover crops have shown to reduce plant pathogens survival both in laboratory and field plots. The suppression is due to the volatile glucosinolate (GLS) and isothiocyanate (ITC) content cruciferous plants. As a part of a project at NIBIO Ås, an in vitro experiment with allyl ITC were done to look at the effect on survival of Heterodera avenae, Fusarium graminearum and Microdochium nivale, with increasing allyl ITC concentration. Also, a closed jar experiment was conducted to look at the effects of cruciferous plants on suppression of survival of Heterodera avenae and Fusarium graminearum. The aim of the in vitro experiment was to see at which concentrations of allyl ITC that suppressed fungal growth of F. graminearum and M. nivale and hatching of the cereal cyst nematode H. avenae. The EC50-values of the F. graminearum isolates 200 630, 201 196 and 202 058, were 6.36, 9.50 and 7.62 mg/L respectively. EC50-values of M. nivale isolates 200 136, 200 231 and 202 786, were 8.60, 10.83 and 10.27 mg/L respectively. For H. avenae, the EC50-value was at 5.66 mg/L. This demonstrates a differentiation of EC50-values between nematodes and fungi, but also between fungal species and fungal isolates. A closed jar experiment was conducted to see if incorporation of cruciferous plants in soil may affect the survival of H. avenae and F. graminearum. Two different time exposures in jars with either two or eight weeks of exposure in jars, were performed. After treatments in jars, the cysts were given either a diapause or no diapause treatment. The total number of eggs and J2 were significantly lower for cysts exposed for eight weeks in jars compared to two weeks, but the total number of eggs and J2 were almost equal for diapause and no diapause. The number of hatched J2 (15°C) for cysts with diapause treatment had significantly higher number of J2 than no diapause treatment. Also, the number of hatched J2 were significantly higher for two weeks exposure in jars compared to eight weeks. The mycelial growth from F. graminearum on oat spikelet incorporated in soil with plant material was not different from untreated.