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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Adaptive Cropping Systems Laboratory » Research » Publications at this Location » Publication #405557
Research Project: Experimentally Assessing and Modeling the Impact of Climate and Management on the Resiliency of Crop-Weed-Soil Agro-Ecosystems

Location: Adaptive Cropping Systems Laboratory

Title: A comparison of wheat phenology submodules

Author
item Paff, Kirsten
item Timlin, Dennis

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/8/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Accurately simulating wheat (Triticum aestivum L.) phenology is critical for process-based crop models. The duration of growth stages affects the crop's ability to accumulate biomass and grain yield, and the impact of stresses is more severe if they occur at critical stages. Phenological development is primarily affected by temperature and photoperiod. Most crop models account for temperature using linear functions that calculate thermal time accumulation, however, experimental data has shown that the assumption of linearity breaks down when temperatures are high or near the inflection points. Nonlinear functions have been proposed to address this issue. This study compared the results of three different wheat phenology submodules. The widely used DSSAT CERES-Wheat model simulates phenology using 3-segment linear temperature and vernalization responses and a nonlinear photoperiod response. A nonlinear temperature submodule created by Wang and Engel was substituted into the DSSAT CERES model, while the photoperiod and vernalization submodules were kept constant. Finally, a phenology submodule created by Streck et al. that combined the Wang and Engel nonlinear temperature submodule with an improved nonlinear vernalization submodule was used. The study used observed data from the International Heat Stress Genotype Experiment, which grew two spring-wheat cultivars at six locations across the globe (Sudan, India, Bangladesh, Egypt, and two locations in Mexico). All treatments were well watered and fertilized, so the main differences between treatments were temperature and photoperiod. A subset of the data was used for model calibration. Crop models are important tools for examining the impacts of climate change and evaluating adaptation strategies, therefore it is vital for their sub-modules, including the phenology sub-module, to be accurate under a wide range of climate conditions.