Biomechanical response of the above-ground organs in tomato seedling at different age levels under wind-flow disturbance

Abstract

The wind-flow disturbance is a potential green biophysical method for preventing tomato seedlings from overgrowth in plant factories. Firstly, the biomechanical properties of the leaf, stem, and lateral branch in the tomato seedling at five age levels were determined by uniaxial tension tests. After which, five fluid-solid coupled finite element (FE) models were developed, each with a wind field and one of the five ages of seedling model formed by a stem and several lateral branches and leaves. The FE model with average tissue biomechanical data was capable of reproducing the experimental swing angle vs. time curve. Three multiple linear regression analysis models revealed that the strong seedling index was the most significant factor affecting the maximum stress in the tomato seedling, followed by the wind velocity and seedling age. When the strong seedling index, wind velocity and seedling age were 0.02, 2 m/s, and 25 days, the maximum Von Mises stress in the leaf and the lateral branch exceeded their failure stress, indicating that the inhibition of overgrowth seedling under wind-flow disturbance can be attributed to the tomato seedling's micro-mechanical damage caused by wind and result in further physiological response. This study provides an effective method for objectively investigating the biomechanical response of the internal tissues in tomato seedling subjected to wind-flow disturbance (stimulation), which cannot be achieved through actual experiment observation.