Physiological analysis of far-red effects on fruit-bearing tomato plants

Supplementary lighting in greenhouse horticulture during the winter months is necessary to achieve year-round production at northern latitudes. The transition towards new light technologies, like Light-Emitting Diodes (LEDs) would allow growers to decrease their expenses in terms of electricity and supply the most suited light spectra to optimise plant growth and production. The addition of far-red light (FR, 700-800 nm) to a background lighting has been reported to improve fruit yield in tomato, both in terms of quantity and quality. However, most of the available knowledge on the perception and response to FR was developed on young vegetative plants and in environmental conditions far from comparable to greenhouse cultivation. Therefore, research focusing on the effects of FR on a model crop like tomato is necessary to guide science-based applications of this technology in the horticultural sector. The aim of the proposed research is to deepen our understanding of the perception and transduction of FR in fruit-bearing tomato plants and to explore different solutions for FR application in greenhouse cultivation. This research will focus on: i) determining the most suitable timing and intensity of FR to maximise yield improvements and minimize energy consumption; ii) studying the location of FR perception in fruiting tomato plants and iii) characterising the genotypic variation in FR-induced yield improvements among different tomato cultivars. The expected results of this research will improve our knowledge on the effects of FR on fruit-bearing plants, supply new targets for breeding purposes and ultimately stimulate the transition to energy-efficient LEDs.