TastyStrawberry: Sustainable optimization of modern cultivation practice for taste improvement of Norwegian strawberries

Strawberries are an important berry species with long traditions in Norway, and Norwegian strawberries have a high status among consumers. The climate in Norway is favorable for growing tasty strawberries, but the short season has led to increased imports to meet year-round demand. In order for Norwegian strawberries to be able to compete with imported berries and retain their high status, it is crucial to focus on taste and quality. The increased import of strawberry plants has opened up new opportunities for production, including the use of high-yielding imported plants in substrate cultivation under plastic tunnels. This meets many of the challenges within Norwegian strawberry production and has also made production in greenhouses and closed systems relevant. However, this development has also challenged the taste of Norwegian strawberries. The taste of strawberries is a complex interaction between sugar, acid and aroma substances, and cannot be changed after harvesting. Variety, cultivation practices, temperature and light are all factors that affect the quality of taste. In order to improve taste in modern production systems, it is necessary to understand how these factors work together. The main goal of TasteyStrawberry is to develop new knowledge to optimize the taste of strawberries produced during an extended growing season in Norway. The project is in its second season. Experiments have been carried out both tunnels and under controlled conditions to identify factors that affect the strawberry taste. Controlled experiments under different light and temperature conditions will reveal the importance of the Norwegian climate on the berry taste. In greenhouse specific light qualities with LED has tested for optimization of taste in three varieties. Cultivar trials with a total of 19 cultivars have been tested for taste and yield at two different locations. Different fertilization regimes throughout a long season have been carried out to uncover potential for optimization in modern production systems. Investigation on the effect of different fertilization strategies have been done on the strawberry variety Favori, focused on levels of nitrogen, both in the form of ammonium and nitrate. The results from our trials will be completed during the winter. Further research will focus on adjusting the ratio between ammonium and nitrate in different growth phases of the season to fine-tune the sugar and acid balance in the strawberries. Producers in tunnels within the project group and externals have been followed up by advisers gaining direct knowledge from the project regarding fertilization and irrigation. Some producers have also tested varieties in their facilities. There has been great interest in greenhouse production, and a new producer has started strawberry production at Jæren with experience from the project. In addition, consumer surveys have revealed a number of interesting aspects of Norwegians' relationship with strawberries and taste, which provides additional knowledge useful for the entire value chain. Among other things, the very high importance placed on taste and food safety among Norwegian consumers and that young people prefer a slightly more tart taste compared to the elderly.

Strawberry is an important berry specie with long traditions in Norway. The Norwegian strawberries have a high status among consumers and are famous for its excellent taste. Despite this preference, there have been a sharp increase in strawberry imports, especially outside the Norwegian season. However, new opportunities for production have made it possible to combine the high yield potential of the imported strawberry plants with cultivation in substrate under high plastic tunnels. Also, greenhouse production and production in closed systems have become relevant for strawberry production in Norway. However, in parallel with development of new production systems and increasing imports, the taste and flavour quality of Norwegian berries have been challenged. Studies of consumer taste preferences emphasizes the importance of sweetness and the intensity of strawberry flavour. The strawberry taste is complicated and specific, and preferences is affected by several factors such as age and gender. Meeting the strawberry flavour preferences is a complex interaction between sugars, acids, and aroma substances. It is nevertheless known that the taste and flavour experience is reduced by factors which decrease the total content of aroma substances and sugars, and increase the acid content. Since the ripening process for strawberry stops at harvest, the quality cannot be improved after picking. The role of preharvest factors under modern production systems must be understood to improve consumers approval and optimize the end-product. Genotype/cultivar, cultivation practice and temperature/light are all factors that alone and in combination is proven to affect taste quality. The main goal of StrawberryTaste is therefore to develop R&D-based knowledge that will create a basis for optimizing external factors for the best possible taste of strawberries produced in modern production systems in Norway, in step with increased value creation of Norwegian berries.