A sunflower simulation model: I. Model development

Chapman, S.C., Hammer, G.L. and Meinke, H. (1993) A sunflower simulation model: I. Model development. Agronomy Journal, 85 3: 725-735.

Author Chapman, S.C.
Hammer, G.L.
Meinke, H.
Title A sunflower simulation model: I. Model development
Journal name Agronomy Journal   Check publisher's open access policy
ISSN 0002-1962
Publication date 1993-05
Sub-type Article (original research)
Volume 85
Issue 3
Start page 725
End page 735
Total pages 11
Place of publication Madison, WI, United States
Publisher American Society of Agronomy
Language eng
Formatted abstract
In dryland farming systems, opportunities to improve sunflower (Helianthus annuus L.) yields are mostly associated with management decisions made at planting. Dynamic crop simulation models can assist in making such decisions. This study reports the structure of QSUN, a simple and mechanistic crop model for sunflower, and how it accounts for the dynamic interaction of the crop with the soil and aerial environment. The model incorporates several recent approaches to simulation of crop growth in dryland conditions. QSUN estimates growth, development, and yield of a sunflower crop. Daily inputs of temperature and photoperiod drive a phenology submodel to predict stages of emergence, bud visibility, 50% anthesis, and maturity. Using these stages, the growth submodel, driven by daily inputs of radiation, rainfall, and temperature, estimates leaf area production and senescence and soil water extraction. Biomass production is calculated from the amount of radiation intercepted by leaves or from the amount of water accessible in the root zone, depending on whether radiation or water is limiting crop growth. Seed yield is calculated from the allocation of biomass to the grain following anthesis. Sensitivity testing of the model under several irrigation regimes indicated that QSUN was most sensitive to the rate at which partitioning of biomass to grain increased, the ratio of biomass produced to water transpired, and the rate of soil water extraction in a water limited situation. The model was tested against independent data, with actual phenological data and was able to satisfactorily predict leaf area index (r2 = 0.65), total biomass (r2 = 0.96), and grain yield (r2 = 0.93), thus providing tool for use in simulations studies and to assist in management decision making.
Keyword Arid tropical environment
Radiation use efficiency
Comparative productivity
Biomass accumulation
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: Queensland Alliance for Agriculture and Food Innovation
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Citation counts: TR Web of Science Citation Count  Cited 96 times in Thomson Reuters Web of Science Article | Citations
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Created: Mon, 07 Mar 2011, 15:30:19 EST