Abstract: Methods and systems for assessing wide-area performance of a crop variety using a linear mixed model that incorporates geostatistical components and includes parameters for fixed effects, random effects and covariances. A wide-area database is constructed that includes covariate data, spatial coordinates of testing locations of one or more crop varieties, geographic areas in which the testing locations reside, and performance trait values of one or more crop varieties. The parameters for the fixed effects, random effects and covariances are estimated by fitting the linear mixed model with data in the wide-area database. Long-term expected performance of the crop variety may be estimated using the parameter estimates. Average performance of the crop variety for a given time period may be predicted using the parameter estimates.