Michel Verheul
Seniorforsker
(+47) 934 08 525
michel.verheul@nibio.no
Sted
Særheim
Besøksadresse
Postvegen 213, NO-4353 Klepp stasjon
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Introduction: Greenhouse tomato growers face the challenge of balancing fruit size and chemical quality traits. This study focused on elucidating the interplay between plant branching and light management on these traits, while maintaining consistent shoot density. Methods: We evaluated one- and two-shoot plants under varying top light intensities using high-pressure sodium lamps and light-emitting diode (LED) inter-lighting. Results: The reduced yield in the two-shoot plants was mainly due to smaller fruit size, but not due to source strength limitations, as evaluated through leaf weight ratio (LWR), chlorophyll index, specific leaf area (SLA), leaf dry matter percentage, and stem soluble carbohydrate accumulation. Enhanced lighting improved fruit weight and various fruit traits, such as dry matter content, total soluble carbohydrate content, and phenolic content, for both one- and two-shoot plant types. Despite lower mean fruit weight, two-shoot plants exhibited higher values for chemical fruit quality traits, indicating that the fruit growth of two-shoot plants is not limited by the available carbohydrates (source strength), but by the fruit sink strength. Diurnal analysis of fruit growth showed that two-shoot plants had reduced expansion during light transitions. This drop in fruit expansion was not related to changes in root pressure (measured as xylem sap exudation from decapitated plants), but might be related to diminished xylem area in the stem joint of the two-shoot plants. The concentration of several hormones, including cytokinins, was lower in two-shoot plants, suggesting a reduced fruit sink capacity. Discussion: The predominant impact of branching to two-shoot plants on sink capacity suggests that the fruit growth is not limited by available carbohydrates (source strength). Alongside the observation that light supplementation and branching exert independent additive effects on fruit size and chemical traits, this illuminates the potential to independently regulate these aspects in greenhouse tomato production.
Forfattere
Michel VerheulSammendrag
Det er ikke registrert sammendrag
Green Greenhouse growth
Divisjon for matproduksjon og samfunn
Emission-free smart greenhouse farming: increasing tomato production while reducing energy needs in a closed greenhouse system using an Environmental Control System
Økologisk veksthusdyrking i bakken ved norske forhold
Divisjon for matproduksjon og samfunn
JordbærSmak: En optimalisert moderne produksjonsteknologi for mer smakfulle norske jordbær
Strawberry is an important berry specie with long traditions in Norway. Norwegian berries have a high status amongconsumers. The climate in Norway is suited to produce strawberries with excellent taste, but the season is short andthe consumers' desire for strawberries around the year has led to a sharp increase in imports in recent years. IfNorwegian strawberries are to compete with imported berries during the growing season and retain their high status,it is important to focus on quality. The opening of import of strawberry plants, have given new possibilities forproduction. The high yield potential of imported strawberry plants combined with growing in substrate in highplastic tunnels meets many of the challenges for strawberry production in Norway. In extension of this, production ofstrawberries in greenhouses and in closed systems have also become relevant. In parallel with new productionsystems and increased import, the taste-quality of Norwegian berries has been challenged. A question that has beenraised is: "Why is there so little difference in the taste of Norwegian and imported strawberries?". However,strawberry taste is complex and specific, and preferences change with several factors, such as age and gender.Strawberry flavor is a complex interaction between sugar, acid, and aroma substances. Since the ripening processstops at harvest, the content of these cannot be changed after picking. Cultivar, cultivation practices, temperatureand light are factors that alone and in combination can affect the quality of taste. The role of the cultivation factorsin modern production systems must be understood in order to improve the consumer's taste experience andoptimize the quality of the final product. TastyStrawberry's main goal is therefore to develop new knowledge thatwill create a basis for optimizing the taste of strawberries produced in modern production systems during anextended growing season in Norway.
Divisjon for matproduksjon og samfunn
Utnyttelse av trefiber og avfallsstrømmer for bærekraftige og sirkulære dyrkingsmedier i hagebruket (‘SUBTECH 2.0’)
Divisjon for matproduksjon og samfunn
Sustainable growth of the Norwegian Horticulture Food System – GreenRoad GS35 (“GrøntStrategi mot 2035)
The main aim of GreenRoad is to deliver knowledge and solutions for increased value creation and sustainability in the horticultural food system in Norway.