Articles
Impact of sub-radiation with LED light during cultivation of Mentha spicata on growth responses and leaf coloring
Article number
1296_83
Pages
651 – 658
Language
English
Abstract
Mint is a popular herb marketed as a fresh potted plant.
A dense appearance and healthy, green leaves are considered important quality traits for commercialization.
However, when cultivating this plant at a high plant density, yellowing of the lower leaves may occur.
To reduce the leaf yellowing, additional light applied underneath the crop canopy was evaluated for Moroccan mint (Mentha spicata ‘Maroccan’). Plants were scored for overall plant morphology with special attention to chlorophyll content of upper (fully light exposed) and lower (shaded) leaves.
We postulated that additional LED light (light-emitting diodes, λmax = 440 nm) given at the level of the lower leaves would promote chlorophyll synthesis and therefore prevent yellowing of the lower leaves.
The action of additional light (+19 µmol m‑2 s‑1 at the level of the lower leaves), given during a 16-h photoperiod, was evaluated.
This light treatment significantly increased chlorophyll levels at the upper (+7%) and lower (+28%) leaves compared to control plants.
Furthermore, significant increases in the number of leaves (+19%), fresh weight (+13%) and dry weight (+15%) were observed.
These features add to the market value of mint as a fresh product.
Furthermore, additional light was evaluated 1) only during the dark period, or 2) during the entire 24-h cycle.
Plants from both treatments showed strong phototropic response of the stem orientation toward the LED light used.
Leaves were heavily curled.
In both treatments, chlorophyll levels of the lower leaves increased significantly, but plants from both treatments were not marketable.
However, through optimization of the time that additional LED light underneath the crop was applied, these disadvantages could be eliminated.
A dense appearance and healthy, green leaves are considered important quality traits for commercialization.
However, when cultivating this plant at a high plant density, yellowing of the lower leaves may occur.
To reduce the leaf yellowing, additional light applied underneath the crop canopy was evaluated for Moroccan mint (Mentha spicata ‘Maroccan’). Plants were scored for overall plant morphology with special attention to chlorophyll content of upper (fully light exposed) and lower (shaded) leaves.
We postulated that additional LED light (light-emitting diodes, λmax = 440 nm) given at the level of the lower leaves would promote chlorophyll synthesis and therefore prevent yellowing of the lower leaves.
The action of additional light (+19 µmol m‑2 s‑1 at the level of the lower leaves), given during a 16-h photoperiod, was evaluated.
This light treatment significantly increased chlorophyll levels at the upper (+7%) and lower (+28%) leaves compared to control plants.
Furthermore, significant increases in the number of leaves (+19%), fresh weight (+13%) and dry weight (+15%) were observed.
These features add to the market value of mint as a fresh product.
Furthermore, additional light was evaluated 1) only during the dark period, or 2) during the entire 24-h cycle.
Plants from both treatments showed strong phototropic response of the stem orientation toward the LED light used.
Leaves were heavily curled.
In both treatments, chlorophyll levels of the lower leaves increased significantly, but plants from both treatments were not marketable.
However, through optimization of the time that additional LED light underneath the crop was applied, these disadvantages could be eliminated.
Publication
Authors
L. Schenkels, A. Lauwers, W. Saeys, M.P. De Proft
Keywords
sub-radiation, leaf coloring, mint, light emitting diodes, supplemental light
Groups involved
- Division Precision Horticulture and Engineering
- Division Greenhouse and Indoor Production Horticulture
- Working Group Organic Greenhouse Horticulture
- Working Group Protected Cultivation, Nettings and Screens for Mild Climates
- Working Group Light in Horticulture
- Working Group Vegetable Grafting
- Working Group Computational Fluid Dynamics in Agriculture
- Working Group Mechanization, Digitization, Sensing and Robotics
- Working Group Modelling Plant Growth, Environmental Control, Greenhouse Environment
- Working Group Greenhouse Environment and Climate Control
- Working Group Design and Automation in Integrated Indoor Production Systems
- Commission Agroecology and Organic Farming Systems
- Division Landscape and Urban Horticulture
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