1. General Model Information



Main medium: terrestrial
Main subject: biogeochemistry, agriculture
Organization level: population
Type of model: not specified
Main application:
Keywords: crop growth, phenology, development, yield, small grain, wheat, barley, phyllochron, thermal time, Triticum aestivum, Hordeum vulgare,


Dr. Gregory S. McMaster
GreatPlains System Research Unit
Fort Collins, CO 80522
Phone: (970)-490-8340
Fax : (970)-490-8310
email: greg@gpsrv1.gpsr.colostate.edu

Dr. Wallace Wilhelm
117 Keim Hall
University of Nebraska
Lincoln, NE 68583-0934
Phone: +1 402-472-1512
Fax : +1 402-472-7904
email: wwilhelm@unl.edu


Wilhelm, W.W., McMaster G. S and others
Fulllist of current cooperators


"SHOOTGRO emphasizes the development and growth of the shoot apex of small-grain cereals such as winter and spring wheat (Triticum aestivum L.) and spring barley (Hordeum vulgare L.). To better incorporate the variability typical in the field, up to six cohorts, or age classes, of plants are followed using a daily time step. Within each median plant of a cohort, the appearance of each tiller is simulated, and for each culm (main stem and tillers), the phenological growth stage and appearance, growth, and senescence/abortion of each leaf, internode, spikelet, floret, kernel, rachis, and chaff is simulated. The model has been evaluated under conditions from the Great Plains, Pacific Northwest, South Africa, Italy, and England." Source : SHOOTGRO Home Page

"SHOOTGRO simulates and reports date of appearance, size, date of senescence, and frequency in the canopy of all above-ground parts of the small grain modeled. Events are timed in terms of the phyllochron (the interval between appearance of successive leaves on a culm) in the model.
The algorithm reported by Baker et.al. (1980) is used to predict the phyllochron based on the rate of change in daylength at the time of seedling emergence. Developmental and growth processes are limited by the availability of light, nitrogen, and water. The individual plants in the community are divided into as many as six cohorts (based on time of emergence). Use of cohorts (each have a different time of emergence and therefore somewhat different conditions during each developmental phase) allows the simulation to reflect the variation between plants seen in the field. In addition to growth parameters, the model continuously reports crop development in three commonly used stages - Feekes, Zadoks-Chang-Konzak, and Haun.
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Model purpose
To simulate development and growth of small grains (winter and spring wheat and spring barley) from easily obtained input and weather data in response to environmental factors (nitrogen, light, and water availability) based on accumulation of thermal time."
Source :

Joergensen S.E., B. Halling-Soerensen and S.N Nielsen (Edts.) 1996: Handbook of Environmental and Ecological Modelling. CRC Press Boca Raton et al. 672 pp.

The following Information on Submodels can be found on the SHOOTGRO Home Page:

II. Technical Information II.1 Executables:
Operation System(s): DOS, UNIX
II.2 Source-code:
Programming language(s): standard FORTRAN 77
II.3 Manuals:
II.4 Data:

II. Technical Information

II.1 Executables:

Operating System(s): DOS, UNIX

II.2 Source-code:

Programming Language(s): standard FORTRAN 77

II.3 Manuals:

II.4 Data:

III. Mathematical Information

III.1 Mathematics

III.2 Quantities

III.2.1 Input

III.2.2 Output

IV. References

McMaster, G.S., and W.W. Wilhelm. 1997. Conservation compliance creditfor winter wheat fall biomass and implication for grain production. Journal of Soil and Water Conservation 52:000-000.

Wilhelm, W.W., and G.S. McMaster. 1996. Spikelet andfloret naming scheme for grasses with spike inflorescences. Crop Science36:000-000

McMaster, G.S. 1997. Phenology, development, and growthof the wheat (Triticum aestivum L.) Shoot apex: A review. Advances inAgronomy 59:63-118. or 58:000-000.

McMaster, G.S., and W.W. Wilhelm. 1995. Accuracy of equationspredicting the phyllochron of wheat. Crop Science 35:30-36.

McMaster, G.S., W.W. Wilhelm, and P.N.S. Bartling. 1994.Irrigation and culm contribution to yield and yield components of winterwheat. Agronomy Journal 86:1123-1127.

Harrell, D.M., Wilhelm, W.W., and McMaster, G.S., 1993. SCALES: Acomputer program to convert among three developmental stage scales for wheat.Agron, J. 85: 758-763.

McMaster, M., Klepper, S., Rickmann, B.,Wilhelm, W.W., and Willis, W.O.,1991.Simulation of above-ground vegetative development and growth ofunstressedwinter wheat. Ecol. Modelling 53: 189-204.

McMaster, G.S., Morgan, J.A., and Wilhelm, W.W., 1992. Simulating winterwheatspike development and growth. Agric. For. Metreol. 60: 193-220.

McMaster, G.S., Wilhelm, W.W., Morgan, J.A., 1992. Simulating winterwheat shoot apex phenology. J. Agric. Sci. Camb. 119: 1-12.

McMaster, G.S., and W.W. Wilhelm, 1997. Growing degree-days: One equation, two interpretations. Agric. For. Meteorol. 000:000-000.

McMaster, G.S. 1993. Another wheat (Triticum spp.) model? Progress and applications in crop modeling. Rivista di Agronomia 27:264-272.


V. Further information in the World-Wide-Web

  • SHOOTGRO Home Page

VI. Additional remarks

Last review of this document by: Greg McMaster and T.Gabele: 24-Sep-1997 updated model author
Status of the document:
last modified by Tobias Gabele Wed Aug 21 21:44:49 CEST 2002

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