Light-emitting diodes (LEDs) have become the leading artificial light source for plant
factories due to their efficiency and flexibility. Recent study titled “Effects of different
light intensity on the growth of tomato seedlings in a plant factory” investigates the impact of
different light intensities, using red and blue LEDs, on the growth of tomato seedlings. The results
indicate that a light intensity of 240 μmol/m2/s is optimal for promoting robust plant growth and can effectively
replace greenhouse conditions, offering energy savings and reduced emissions.
Modern society faces a "trilemma" involving food shortages, limited resources, and environmental
degradation. This issue is amplified by urban population growth and a declining agricultural workforce. To address this,
innovative plant production systems are needed to increase food yield and quality while minimizing resource consumption and
environmental impact. One such system is the Plant Factory with Artificial Lighting (PFAL), which can enhance resource efficiency,
productivity, and plant quality without pesticides.
Tomato seedlings are sensitive to light intensity, which affects their growth and physiological
changes. This study explores the effects of different light intensities, particularly focusing on the combination
of red and blue LEDs, on tomato seedlings in a controlled environment.
Tomato seeds were germinated and transplanted into trays in a controlled environment with a 12-hour photoperiod, temperatures of 25°C/20°C (day/night), and humidity levels of 65%-75%. Four different light intensity treatments (60, 150, 240, and 330 μmol/m2/s were compared to natural sunlight, with a fixed red-blue LED ratio of 7:3.
Various growth indicators, such as plant height, stem diameter, dry matter accumulation, chlorophyll content, and photosynthetic properties, were measured. Statistical analyses were conducted using SPSS 22.0 and Origin Pro 2022.
The results showed significant differences in the growth of tomato seedlings under different light intensities. The optimal stem diameter and dry weight were achieved at 240 μmol/m2/s. Lower light intensities led to elongated plants with insufficient growth, while higher intensities did not significantly improve growth metrics.
Chlorophyll content was highest at 240 μmol/m2/s, indicating that this light intensity is most effective for promoting photosynthesis and plant health.
The net photosynthetic rate was highest at 240 μmol/m2/s, surpassing even natural sunlight conditions. This intensity also optimized stomatal conductance and intercellular CO2 concentration, crucial for efficient gas exchange and photosynthesis.
Effects of Different Light Intensity on the Growth of Tomato Seedlings :
available at
https://www.researchgate.net/publication/376044401
_Effects_of_different_light_intensity_on_the_growth_of
_tomato_seedlings_in_a_plant_factory