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Background and Aims: The production system of cut-rose (Rosa × hybrida) involves a complex combination of plant material, management practice and environment. Plant structure is determined by bud break and shoot development while having an effect on local light climate. The aim of the present study is to cover selected aspects of the cut-rose system using functional-structural plant modelling (FSPM), in order to better understand processes contributing to produce quality and quantity., Methods: The model describes the production system in three dimensions, including a virtual greenhouse environment with the crop, light sources (diffuse and direct sun light and lamps) and photosynthetically active radiation (PAR) sensors. The crop model is designed as a multiscaled FSPM with plant organs (axillary buds, leaves, internodes, flowers) as basic units, and local light interception and photosynthesis within each leaf. A Monte-Carlo light model was used to compute the local light climate for leaf photosynthesis, the latter described using a biochemical rate model., Key Results: The model was able to reproduce PAR measurements taken at different canopy positions, different times of the day and different light regimes. Simulated incident and absorbed PAR as well as net assimilation rate in upright and bent shoots showed characteristic spatial and diurnal dynamics for different common cultivation scenarios., Conclusions: The model of cut-rose presented allowed the creation of a range of initial structures thanks to interactive rules for pruning, cutting and bending. These static structures can be regarded as departure points for the dynamic simulation of production of flower canes. Furthermore, the model was able to predict local (per leaf) light absorption and photosynthesis. It can be used to investigate the physiology of ornamental plants, and provide support for the decisions of growers and consultants.

Garden-orchard systems (GOS) consist in intercropping various vegetables with fruit trees. They are very promising to produce fruits and vegetables in sufficient quantity and of adequate quality while limiting environmental impacts. We assessed the effects of apple trees on the spatiotemporal variations of microclimatic conditions and soil properties, and their influence on the growth of two vegetables (radish and lettuce). We performed measurements on five vegetable beds situated at different distances from apple tree rows (from 1.5 to 5 m). Vegetable beds near the apple trees received on average 8% less radiation. Air temperature near the trees was on average 1.5 °C lower during daytime while air relative humidity was up to 5% higher. Apple trees improved the soil surface properties. Soil organic matter was up to 40% higher in the vegetable beds near the rows whereas soil bulk density was 16% lower, N mineralization was up to two times faster. Mineral N and bulk density were the primary limiting factors for the growth of radish while lettuce growth was mainly affected by microclimate. Our results provide a framework to define a spatial arrangement of GOS that optimize the ecosystem services of fruit trees and, therefore, the productivity of GOS. [ABSTRACT FROM AUTHOR]

• Supplemental LED light only compared to HPS + LED lighting increased average fruit fresh weight. • Adding far-red LED to red/blue LED light increased the production of soluble sugar in the fruit. • Far-red LED light increased the effect of the dilution by soluble and storage compounds, but reduced the dilution by water. • Far-red LED light strongly increase glucose, fructose and sucrose concentration in the fruit. Understanding how greenhouse crops respond to supplemental lighting with light-emitting diodes (LEDs) compared with traditional lighting systems is essential to utilize the full potential of LEDs and their further adoption in energy efficient greenhouses. This study quantified the effects of supplemental lighting with high-pressure sodium (HPS) lamps and LED light on the dynamics of fruit growth and composition in tomato (Solanum lycopersicum L.). Two tomato genotypes ('Foundation' and 'Progression') were grown under daylight supplemented either with HPS (125 μmol m−2 s−1) combined with red/blue LED lighting (106 μmol m−2 s−1, HPS + LED light treatment) or red/blue LED light only (106 + 110 μmol m−2 s−1, LED + LED light treatment); and two genotypes ('Foundation' and 'NUN09204') under daylight supplemented either with red/blue LED light (200 μmol m−2 s−1, red/blue LED light treatment) or red/blue LED + far-red LED light (200 μmol m−2 s−1 + 40 μmol m−2 s−1, red/blue + far-red LED light treatment). Fresh weight and composition in glucose, fructose, sucrose, starch, citric acid and malic acid of tomato fruits at different stages of development were measured and analyzed in terms of three main underlying components: water dilution, dilution by soluble and storage compounds and metabolism. Growing fruits under the LED + LED compared to the HPS + LED light treatments increased average fruit fresh weight in all genotypes. The red/blue + far-red LED light treatment increased the production of soluble sugar, increased the dilution by soluble and storage compounds, and reduced water dilution leading to a strong increase in glucose, fructose and sucrose concentration in the pericarp. The LED + LED light treatment did not affect the metabolism of fruit biochemical compounds compared to the HPS + LED light treatments, but caused small changes in water dilution, which were reflected in the concentration of biochemical compounds. Dilution and metabolism were involved in genotypic differences in fruit composition. Our results show that altering the spectral composition of the supplemental light in energy efficient greenhouses can be done without an effect on fruit quality or even with an improvement of tomato fruit quality. Possible physiological processes underlying these light-induced changes in fruit biochemical compounds during fruit development in different genotypes were discussed. [ABSTRACT FROM AUTHOR]