GENERATION OF SOLAR-RADIATION VALUES FOR USE IN WEATHER FILES OF CROPSIMULATION-MODELS

A user friendly computer program for generating solar radiation values was developed for three sites (Mayaguez, Pence and Isabela) in Puerto Rico. The program produces solar radiation data compatible with that of the weather files of the crop models in the Decision Support System for Agrotechnology Transfer (DSSAT), developed by the International B enchmark Sites Network for Agrotechnology Transfer (IBSNAT). The progr am randomly generates solar radiation values within a range determined by statistical analysis of available observed solar radiation data. A chi-square goodness-of-fit test showed that, for a given Julian day a nd site, the random values produced are uniformly distributed (non-bia sed) over the pre-determined confidence interval range (alpha = 0.05). Results also indicate that the annual trend in the program-generated solar radiation values throughout the year was similar to that of the observed values. Using the randomly generated solar radiation values, the output parameters (pod yield, seed yield, shelling percentage, wei ght per seed, seed number, maximum LAI, biomass, stalk and harvest ind ex) of the DSSAT dry bean model were similar to the variables generate d with observed solar radiation data.