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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.

2020

To document

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.

To document

Abstract

Growth cessation and floral initiation in black currant and red raspberry are jointly controlled by the interaction of temperature and short-day (SD) conditions, and the processes coincide in time in both natural and controlled environments. The critical photoperiods for the two successional responses were found to be approximately 15 and 16 h, respectively, for a range of Western-European black currant cultivars. Both cessation of growth and floral initiation are promoted and enhanced by increasing temperature in the 9 to 24°C range. In contrast, biennial-fruiting red raspberry has a maximum temperature limit for growth cessation and floral initiation. At temperatures above 16°C, most cultivars grow and remain vegetative regardless of day length conditions, at 12 to 16°C they cease growing and initiate flower primordia in photoperiods <15 h, while at temperatures ≤12°C they cease growing and initiate floral primordia regardless of day length. In the annual-fruiting (primocane) types of red raspberry on the other hand, floral initiation is not constrained by high temperature, but readily takes place at temperatures up to 30°C. In addition, floral initiation is also enhanced by long day (LD) conditions in most of these cultivars. Another fundamental physiological difference is that while floral primordia of the biennial types become dormant after initiation, they proceed directly to anthesis in the annual-fruiting types. Chilling at -5°C, and in the -5 to +5°C temperature range were found to be optimal for breaking of bud dormancy and promotion of flowering in black currant and red raspberry, respectively. In black currant, 14 weeks of chilling were optimal, while for raspberry, 20 or more weeks were required for full dormancy release and promotion of flowering along the entire length of the raspberry cane. The consequences of climate warming for the production of these species in different climatic regions are discussed.