How to Manage Pests

Interactive Tools and Models: ALFALFA 1.4

ALFALFA 1.4 is a model that simulates growth and development of the alfalfa plant. The model is based in integrative plant physiology and morphology. Beginning with tissue- and organ-level information, the growth of shoots, including individual leaves and stem internodes, is simulated for up to five age classes of stems. Perennial, underground structures (crown, taproot, and fibrous roots) are simulated over 10 soil layers. The model includes variations in plant population so that overwintering and stand persistence can be simulated.

The program is driven by daily weather data from standard meteorological reports. Hourly weather variables are derived from the daily data to support the model's hourly time advance. This approach permits simulation of the diurnal patterns of production processes and growth for studying the influences of temperature, radiation, water deficit, and carbon supply.

ALFALFA 1.4 offers a robust structure suited to a wide range of management issues and for coupling to insect and disease models. The Fortran program is organized to allow flexible inputs and outputs with run-time graphics selected from a choice of more than 100 variables.

The model's authors, R. Ford Denison and Bob Loomis, wrote UC ANR Publication 1926, An Integrative Physiological Model of Alfalfa Growth and Development, to accompany the program. This 75-page publication describes the science behind the model, explains subroutines, and includes the executable code.

The project was initiated with the sponsorship of the University of California Statewide Integrated Pest Management Project, with funding from USDA-CSRS Western Regional Project W-161.

Availability of ALFALFA 1.4

• The program, without the manual, is available courtesy of R. Ford Denison here as a zipped file. Important: Place the downloaded file into its own directory, then use a decompression program to expand the 25 files onto your hard disk. Download

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