1. General Model Information



Main medium: terrestrial
Main subject: agriculture
Organization level: population
Type of model: ordinary differential equations
Main application:
Keywords: crop, growth, helianthus annuus, watersupply, nitrogen supply, light interception, radiation use efficiency, phenology, thermal time


Dr. F.J. Villalobos.
Instituto de Agricultura Sostenible (CSIC) - Universidad de Cordoba, Dept. Agronomy, Apartado 3048, 14080 Cordoba, SPAIN.
Phone: +34.57.218 491
Fax: +34.57.202 721
email: ag1vimaf@cc.uco.es



Simulation of sunflower (Helianthus annuus L.) crop growth, development and yield in response to climate and water and nitrogen supply. The model has similar water and nitrogen balances as Ceres-Maize v2. Crop growth is based on radiation interception and a leaf area index-dependent Radiation Use Efficiency. Dry matter partitioning is based on priority relationships for the different organs and the ratios potential growth/total increment in dry matter. Yield determination depends on the number of seeds per plant and on seed growth rates. Phenological development depends on temperature and photoperiod. The different sunflower varieties are described using five genetic coefficients: Thermal time for the juvenile period, Sensitivity to photoperiod, Thermal time from first anthesis to physiological maturity, Maximum seed number per plant and maximum seed growth rate.

Model parentage: Ceres-Maize.

Source of the AbstractCAMASE Register of Agro-ecosystems Models

II. Technical Information

II.1 Executables:

Operating System(s): PC-Compatibles under DOS. Contract necessary: Costs: : None. Comments:

II.2 Source-code:

Programming Language(s): Microsoft FORTRAN.

II.3 Manuals:

II.4 Data:

III. Mathematical Information

III.1 Mathematics

III.2 Quantities

Rate variables: Above ground: phenological development, crop growth, growth of plant organs, evaporation, transpiration (and others). Below-ground: percolation rate, water content, irrigation, root growth (mass and length).

State variables: Above ground: biomass (total, and per crop organ e.g. leaf, stem, root, head), leaf area index, number of flowers and seeds, seed mass. Below-ground: soil water content (per layer), root length, nitrate content, ammonium content (all per layer).

III.2.1 Input

Geographical latitude and longitude, weather data (daily radiation, minimum and maximum temperature), rainfall, five genotype specific parameters physical and hydrological soil properties, crop and soil management information. Input check in model: Partial check.

III.2.2 Output

Crop rate and state variables (e.g. leaf area index), soil rate and state variables (e.g. evapotranspiration).
Basic spatial unit: m2 - ha.
Time interval of simulation: 1 Day.

IV. References

Villalobos, F.J., A.J. Hall & J.T. Ritchie., 1990. Oilcrop-Sun: A crop growth and development simulation model of the sunflower. Phenology model calibration and validation. Inaugural Congress European Society of Agronomy. Pars, 5-7 Diciembre de 1990.
Villalobos, F.J., A.J. Hall & J.T. Ritchie, 1992. Oilcrop-Sun: A crop growth and development simulation model of the sunflower (Helianthus annuus L.). Proceedings 13th International Sunflower Conference. Pisa, Italia. 8-10 Septiembre, 1992. International Sunflower Association. 453-458

V. Further information in the World-Wide-Web

VI. Additional remarks

Parentage: Ceres-Maize
Last review of this document by: Tue Sep 23 1997
Status of the document:
last modified by Joachim Benz Mon Jul 2 18:31:37 CEST 2007

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