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.
2020
Abstract
The triploid pear cultivar ‘Ingeborg’ is currently the main commercial pear cultivar grown in Norway. However, fruit set and subsequent yields of this cultivar have proven to be variable and overall rather low. In order to promote the fruit set, different bioregulators were applied during and after bloom and compared with an untreated control. Investigations were done during the period 2017-2018, at NIBIO Ullensvang, western Norway. Different dosages of both gibberellins (GA3, trade name GIBB 3, 10% active ingredient (a.i.) and GA4/7, trade name Novagib®, 1% a.i.) were applied at full bloom and at petal fall. Additional applications of the growth retardant prohexadioneCa (trade name Regalis®, 10% a.i.) were applied twice, when bourse shoots had 3-5 leaves and after one month later. Ethephon (Cerone (480 g a.i. L-1)) was applied three times starting about 7 days after petal fall with ca. 7- to 10-day intervals. All gibberellin applications significantly increased fruit set compared to the untreated control. One single application with GA3 (3 g ha-1) almost tripled the fruit number per 100 flower clusters when compared with the control (136 and 46, respectively). The yield response was similar (16.8 to 9.6 kg tree-1, respectively). Similar results occurred with one application of GA4/7 (12 g ha-1) with the same crop load level, and the fruit weights were similar to the control (130 g). Prohexadione-Ca treatments significantly reduced shoot growth of the pear trees. Two treatments with 125 g ha-1 or one treatment of 250 g ha-1 reduced the growth by ~35% but had no significant effect on fruit set and yield. The multiple ethephon applications (275 mL ha-1 in total) had no effect on both set and shoot growth, and return bloom compared to the untreated or gibberellin treated trees.
Authors
Fuad Gasi Oddmund Frøynes Belma Kalamujic Stroil Lejla Lasic Naris Pojskic Milica Fotiric Aksic Mekjell MelandAbstract
The diploid Celina/QTee® (‘Colorée de Juillet’ × ‘Williams’), one of the most promising pear cultivars developed by the Norwegian breeding program Graminor, was launched in 2010. In Norway, the flowering is medium to late, while the fruits ripen in the beginning of September. The fruits are attractive with an intense red blush (50%) on a green background. Although, ‘Celina’ is cultivated in the most climatically suitable regions for fruit cultivation, present in Norway, unfavorable environmental conditions for pear pollination can have a very negative effect on fruit set and consequent yield. The aim of this study was to determine the S-alleles of ‘Celina’, as well as its frequently used pollinizers, and, through paternity testing of ‘Celina’ seeds, give a recommendation regarding the most important pollinizers of this pear cultivar. In order to accomplish this, ‘Celina’ and its potential pollinizers were all S-genotyped. After harvest, seeds collected from ‘Celina’ fruit in 2017 and 2018 were genotyped using eleven microsatellite markers. Genomic DNA was also extracted from leaf material collected from ‘Celina’, as well as from five pear cultivars used as pollinizers in the three examined orchards, and analyzed using the same marker set. Subsequently a simple sequence repeat (SSR) database was constructed and used for gene assignment analyses with the aim of quantifying pollen donor contribution from individual pollinizers. The obtained results indicate that ‘Anna’, the only examined pollinizer that was fully cross-compatible with ‘Celina’, together with ‘Fritjof’, the genotype which had the highest flowering overlap with ‘Celina’, proved to be the most successful pollinizers across all seasons and orchards. Although both cultivars were ubiquitous in the examined orchards, either as planted trees or as branches introduced during the flowering period, they were the most abundant pollinizers in only one orchard each. It is therefore possible to conclude that pollinizer abundance has a secondary significance in pollinizer success within investigated ‘Celina’ orchards.
Abstract
No abstract has been registered
Authors
Michel VerheulAbstract
No abstract has been registered
Authors
Michel VerheulAbstract
No abstract has been registered
Authors
Michel VerheulAbstract
No abstract has been registered
Authors
Pia Heltoft ThomsenAbstract
No abstract has been registered
Abstract
BACKGROUND:The predicted and ongoing climate warming can have far-reaching effects on plant growth and life cycle. Therefore, there is need for simple and convenient methods for analysis and monitoring of consequences of the ongoing warming. OBJECTIVE:To demonstrate the usefulness of so-called climate-photothermographs for studying the consequences of the ongoing warming for production of berry crops. METHODS:Local photothermal climates can be expressed by so-called climate-photothermographs, which show the relationship between temperature and daylength for each month of the year in a rectangular coordinate diagram. When superimposing critical response curves for plant development processes on top of such a diagram, the limitations of the given climate for fulfilment of the processes can be readily assessed. RESULTS:Consequences of 2°C warming for critical development processes such as transition to flowering and breaking of winter dormancy in the berry crops raspberry, black currant and strawberry were clearly exposed by the technique. The locations Geisenheim, Germany and Ås, Norway were used as examples. Inadequate winter chill was identified as the most limiting factor for these crops. CONCLUSIONS:We conclude that the technique is an efficient and convenient tool for monitoring the consequences of climate warming for berry crops.
Abstract
Four raspberry cultivars were grown at two different latitudes namely in Geisenheim (DE, 49°60’N; 7°57’E) and in Kapp (NO, 60°42’N; 10°52’E) to investigate the impact of these growing sites on primary and secondary fruit chemical ingredients in the 2017 season. Fruits were harvested at two picking dates each with three field replications. Contents of °Brix, glucose, fructose, sucrose, organic acids, ascorbic acid, polyols, total polyphenols, and anthocyanins were analyzed in the fruits. The geographic growing sites, which in this case is more than10 latitudes between HGU in Germany and NIBIO in Norway, has partly no, partly significant effects on the primary and secondary ingredients of the investigated raspberry cultivars. In respect to the created data set, temperatures shortly before or at the picking dates were not considered. It may be expected that temperatures at harvest have an effect on the fruit ingredients and therefore on a further classification of the samples.
Authors
Sara Duran-Soria Delphine M. Pott William Allwood Erika Krüger Anita Sønsteby Agnieszka Masny Björn Usadel Dorota Jarret Sonia OsorioAbstract
No abstract has been registered