Abstract
Estimates of seeding dates of spring wheat based on climatic criteria at selected prairie locations were compared with observed dates for corresponding crop districts using linear regression and correlation analyses. Correlation coefficients ranged from 0.11 to 0.76 and standard errors of estimates of regression from 3.9 to 8.5 d. Average estimated seeding dates were consistently earlier by about 3–8 d than average observed values reported for periods ranging from 24 to 33 yr.Key words: Correlation, regression, seeding date criteria, soil water content