The role of far-red light (FR) in photomorphogenesis and its use in greenhouse plant production

Abstract

<p>Light energy is one of the most important factors regulating the growth and development of plants. In greenhouses and other controlled- environments in which the natural radiation intensities are often low, plant production relies on supplementary lighting to optimize the photosynthesis, increase production levels, and enable year-round production. For a long time, the research related to artificial lighting sources focused on the optimization of the efficiency of use for photosynthesis. The quality of light in plant production has been widely addressed only recently with the development of advanced LED technology that is energy efficient and enables the control of the spectral composition of light. Red and far-red light are sensed by the phytochromes that trigger several morphological and developmental processes that impact productivity and yield quality. Thus, to efficiently exploit all the advantages of LEDs and to develop LED arrays for specific plant applications, it is essential to understand thoroughly how light quality influences plant growth and development. This paper presents an overview of the recent developments in light quality manipulation, focusing on far-red light and the R: FR ratio, to improve yield and quality of products and to manage plant architecture and flowering in vegetable and ornamental horticulture.</p>

Hybrid Genetic Programming and Multiverse-based Optimization of Pre-Harvest Growth Factors of Aquaponic Lettuce Based on Chlorophyll Concentration

“…This means that when plants are exposed to 4 in proximity to a light source emitting significant infrared, heat energy may cause it to exhibit leaf discoloration, spreading of nodes, and the worst is killing the plant. This measured incident radiation from the artificial light source is different from the far-infrared radiation (FIR) suitable for plant leaves as it is reported to yield no tissue irritation due to lower energy composition [13,[19][20]22]. Violet spectrum consistently exhibited the lowest intensity and Vis/IR for all proximities.…”

“…The use of a Sunlike light-emitting diode (LED) that mimics the natural solar spectrum (400 nm to 700 nm) proves that red and blue light of 9:1 ratio corresponds to better biomass production [19]. Far-red (FR) light has a positive impact on the photomorphogenesis of greenhouse plants [20], monochromatic red and blue lights result in to decrease in stomatal density [21], and red-blue and yellow spectrums affect the air temperature and humidity [22]. The combination of red-blue light (4:1) and 15 hours photoperiod has been tested effective for spinach [23].…”

Supplemental greenhouse lighting increased the water use efficiency, crop growth, and cutting production in Cannabis sativa

“…Responses of plant height in conjunction with internode extension are key to understanding whether the plant stretches mainly because of growth or to compete for more light, triggering shade avoidance syndrome or SAS ( Kump, 2020 ).…”

The effects of far-red light on plant-arthropod interactions and the implications for greenhouse tomato cultivation

“…To address this topic, I studied how changes in the red to far-red light ratio (R:FR) influence the interactions between tomato plants and their associated arthropod community in greenhouse environments, including pests, biological control agents and pollinators. I specifically focussed on the effects of supplemental far-red light (reduced R:FR) due to (1) its role in shade avoidance and the well-described effects on the growth-defence dynamics in plants (Ballaré and Austin, 2019;Fernández-Milmanda et al, 2020; Chapter 2), and (2) the benefits of shade avoidance responses for horticultural crop production (Demotes-Mainard et al, 2016;Kump, 2020). First, I explored how both an increase and decrease in R:FR affect tomato plant morphology and the performance of various arthropod herbivores.…”

“…Shade avoidance responses can be beneficial for crop production in protected horticulture (Pierik & Ballaré, 2021), and the use of far-red light emitting diodes (LEDs) to induce shade avoidance responses is increasingly practiced in greenhouses (Demotes-Mainard et al, 2016;Kump, 2020). The morphological adaptations associated with SAS can improve light interception and thereby improve whole-plant photosynthesis, while the acceleration of flowering can shorten cropping cycles of ornamentals and fruit-forming vegetables (Davis & Burns, 2016;Demotes-Mainard et al, 2016).…”