Integrative Effects of CO2 Concentration, Illumination Intensity and Air Speed on the Growth, Gas Exchange and Light Use Efficiency of Lettuce Plants Grown under Artificial Lighting

Horticulturae

Suliaman Q. Sahari¹  Abdulkarem M. Almogahed¹  Hesham A. Ahmed²  Lie Li²  Yuxin Tong²  Ruifeng Cheng² 

[1] Department of Agricultural Engineering and Modern Technologies, Faculty of Agriculture, Food and Environment, Sana’a University, Sana’a 13020, Yemen;Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, China;

关键词: lettuce;    plant factory;    photosynthesis;    transpiration;    stomatal conductance;    artificial lighting;   

DOI  :  10.3390/horticulturae8030270

来源: DOAJ

【 摘 要 】

This study investigates and quantifies the integrative effects of CO₂ concentration (500, 1000 and 1500 µmol mol⁻¹), illumination intensity (100, 200 and 300 μmol m⁻² s⁻¹) and air speed (0.25, 0.50 and 0.75 m s⁻¹) on the growth, gas exchange and light use efficiency of lettuce plants (Lactuca sativa L.) grown under artificial lighting. The results show that lettuce growth and gas exchange are closely related to CO₂ concentration and illumination intensity, while air speed enhances CO₂ transport during photosynthesis. The most influential two-way interactions were observed between CO₂ concentration and illumination intensity on the fresh and dry weights of lettuce shoots with effect sizes of 34% and 32%, respectively, and on the photosynthesis, transpiration and light use efficiency, with effect sizes of 52%, 47% and 41%, respectively. The most significant three-way interaction was observed for the photosynthetic rate, with an effect size of 51%. In general, the fresh and dry weights of lettuce plants increased by 36.2% and 20.1%, respectively, with an increase in CO₂ concentration from 500 to 1500 µmol mol⁻¹ and by 48.9% and 58.6%, respectively, with an increase in illumination intensity from 100 to 300 μmol m⁻² s⁻¹. The photosynthetic rate was found to be positively correlated with CO₂ concentration, illumination intensity and air speed. The transpiration rate and stomatal conductance increased by 34.9% and 42.1%, respectively, when the illumination intensity increased from 100 to 300 μmol m⁻² s⁻¹. However, as CO₂ concentration increased from 500 to 1500 μmol mol⁻¹ and air speed increased from 0.25 to 0.75 m s⁻¹, the transpiration rate decreased by 17.5% and 12.8%, respectively. With the quantified data obtained, we were able to adequately determine how CO₂ concentration, illumination intensity and air speed interact with their combined effects on the growth of lettuce plants grown in indoor cultivation systems with artificial lighting.

【 授权许可】

Unknown