2017 ASHS Annual Conference
A Process-based Approach for Modeling Leaf Development and Growth in Hardneck Garlic (Allium sativum L.)
A Process-based Approach for Modeling Leaf Development and Growth in Hardneck Garlic (Allium sativum L.)
Friday, September 22, 2017
Kona Ballroom (Hilton Waikoloa Village)
Leaf development and growth are two major processes in crop simulation models. Accurately representing these two processes sets the foundation for modeling changes in leaf number and leaf area throughout the growth and development of a whole-plant. This is critical for processes that highly depend on leaf phenology and morphology, such as gas exchange and carbon allocation, which determine biomass and yield. In this study, we developed a process-based modeling approach that describes the development and expansion of individual leaves for hardneck garlic (Allium sativum L.). We characterized leaf development through the temperature dependence of leaf initiation, maturation and senescence, which is further modified by photoperiod and storage time. In between the process of leaf initiation and leaf maturation, we used a beta function to describe the temperature dependence of leaf elongation, and further applied an allometric relationship between leaf length and leaf area to simulate the gain in leaf area through elongation and expansion over time. Leaf development, elongation and expansion were described for each individual leaf, and was synchronized through leaf development phenology to represent the whole canopy. We calibrated the model with one year of field-collected data on leaf development and leaf area, and validated the model with another year of field data that represented differences in planting dates, storage time, cultivars, location and weather. Comparison between model simulations and field observations showed that the model was able to capture the dynamics of leaf development and growth over time, under a range of climate and management conditions, and was suitable to integrate with other modules within the garlic model that depend on an accurate representation of the crop phenology and morphology.