This week there seemed to have been some confusion about the graphics options in the new DSSAT v3. 1. When you select the GRAPH option under Models, the list of variables you see displayed under GROWTH, WATER, NITROGEN etc. is controlled by the individual output files of the crop models. 2. The current models have two output options : a "short" one which displays 11 variables, and a "long" one which can display up to 46 variables per indvidual option (GROWTH, WATER, etc.). 3. This output option is set by a "switch" in the control section of fileX. You modify this switch through XCREATE or an editor. Another option is to use option 12 "Output Control" of Sensitivity Analysis in the models. 4. The measured variables displayed in the graph are read from fileT. The linkage between fileT and the crop model output files is through a file called DATA.CDE which contains header codes and definitions. You can access this file in DSSAT through DATA - Background - Codes. The codes used in fileT need to match the codes of the crop model files to able to compare simulated and measured data. 5. The "user-selected" variables under "graph" of the model selection allows you to combine variables normally displayed in different sections such as Growth, Water, Nitrogen, etc. For instance in this option you can combine root length density and water content for each individual soil layer. 6. If you feel that the variables displayed under the "long" option of the models is inadequate or does not match your measured variables, you need to contact one of the model developers or modify the model code yourself. We feel that we have covered most of the variables the models can predict under the long option in each specific section. 7. A probabily unknown feature to many of you is the use of the graphics program for display of measured data ONLY. If you select Experiment under the DATA section, and then select Utilities - Graphs, you can display your measured data : DATA --> Experiment --> Utilities --> Graphs You first need to select your field data file before you will be able to graph your data. 8. If you want to graph data for which there is no code in the DATA.CDE file, you can modify this file as explained earlier : DATA --> Background --> Codes --> Data If any of these options is unclear, please let me know. Gerrit Dr. Gerrit Hoogenboom | Dept. of Biol. and Agric. Eng. Assistant Professor | Georgia Station Internet : GHOOGEN @ | The University of Georgia GAES.GRIFFIN.PEACHNET.EDU | Griffin, Georgia 30223-1797 USA PHONE: (404)-228-7216 FAX: (404) 228-7218