Microclimatic, physiological, and structural changes of tomato seedlings during wind-based overgrowth inhibition in vegetable nursery

Abstract

Wind disturbance has emerged as a potential eco-friendly method for seedling cultivation. In this study, an electromechanical device was designed and built to investigate the effects of airflow on the micro-environment and physiological activities of tomato seedlings in seedbeds by controlled experiments. The results indicated that airflow could enhance CO2 concentration near the seedling canopy, accelerate water evaporation from the seedling substrate, and reduce fluctuations in the temperature and humidity in microclimate. The photosynthetic rates of leaves at the 4th, 7th, and 10th positions in seedlings subjected to airflow increased by 25.04 %, 8.23 %, and 8.47 %, respectively, whereas the transpiration rates increased by 15.59 %, 22.28 %, and 13.26 %, respectively when compared to the control group. Additionally, the strong seedling index of seedlings treated with airflow and exogenous iron element increased by 26.02 % and 31.5 %, respectively. Compared to seedlings treated with exogenous iron element, the geometric mean diameter of the pith tissue cells in the stems of seedlings subjected to airflow disturbance was reduced by approximately 18.66 %, while the elastic modulus and bending strength of the stems increased by 10.01 % and 5.89 %, respectively. Similarly, the volume of root tissue cells decreased by 19.22 %, but the elastic modulus of the roots increased by 6.46 %. This study confirms that airflow significantly enhances seedling resilience to abiotic stress, yielding similar or better outcomes than exogenous iron application. It provides both theoretical and practical support for using airflow disturbance as a green technology for cultivating robust seedlings.