Crop morphological parameters such as crop architecture with individual leaf size and leaf size distribution largely determine growth and production of a greenhouse tomato crop. Leaf morphological variables such as leaf mass, leaf surface area and leaf thickness are important for crop-environment interaction. As such, these variables are essential for model-based climate control or model-based planning tools. To cope with the potential changes of the environmental conditions, precise knowledge on the plant morphological development as a response to temperature and assimilation with CO2 concentration as a main driver is required. The area of a single leaf on a plant and in a canopy can be calculated from leaf width (WL) and leaf length (LL). Therefore, plant morphogenesis can be studied by detecting WL and LL changes. The aim of this paper is to establish a model to predict WL and LL dynamics. WL, LL, duration of leaf full widths and length expansion (DTWL, DTLL, respectively) were identified on 1908 tomato leaves of the cultivar ‚Pannovy‘ grown under three temperatures (18, 23, 28°C) and two CO2 concentration levels (400 and 1200 µmol mol‑1) in a semi-closed greenhouse environment. The influence of temperature, CO2 concentration and their interaction on tomato WL, LL, DTWL and DTLL was analysed by a two-way ANOVA. This study is the foundation for future establishment of a dynamic model of leaf area development under different environmental conditions. By testing four different static regression models in this paper, we determined that the logistic model had the best goodness of fit for WL and leaf age (R2=0.76, RMSE=6.13), LL and leaf age (R2=0.75, RMSE=4.39). The results show that temperature had a significant effect on the WL, LL, DTWL and DTLL, whereas CO2 concentration and the interaction between CO2 concentration and temperature had no significant effect on WL, LL, DTWL and DTLL.
Effect of temperature and CO2 concentration on leaf expansion in a tomato crop canopy
Effect of temperature and CO2 concentration on leaf expansion in a tomato crop canopy. W. Yu, O. Körner. ISHS Acta Horticulturae 1296: International Symposium on Advanced Technologies and Management for Innovative Greenhouses: GreenSys2019