EARLY PREDICTION OF SPRING WHEAT YIELDS IN SASKATCHEWAN FROM CURRENT AND HISTORICAL WEATHER DATA USING THE CERES-WHEAT MODEL

Wheat yields were simulated at three locations in Saskatchewan (Swift Current, Saskatoon and Melfort) using the CERES (crop estimation throu gh resource and environment synthesis-wheat)-Wheat model. The simulati ons were made using climatic data of selected (base) years from the st art of the growing season up to the prediction date; data for the rema inder of the season (runout data) were taken from 1960-1990 climate re cords. Years corresponding to the first, second, and third quartile yi eld values were selected for the three study sites. Predicted yields w ere calculated as the means of the yields for the runout years, and we re made at five growth stages: (i) emergence; (ii) terminal spikelet i nitiation; (iii) end of vegetative growth; (iv) start of ear growth; a nd (v) start of grain filling. Predictions using this method were foun d to agree well with measured data, suggesting that simulations made u sing a combination of historical climate records and current weather d ata as inputs provide good indications of yield. Use of these predicti ons would allow producers and those in agribusiness to choose alternat ive actions for minimizing losses when yield prospects are poor. (C) 1 997 Elsevier Science B.V.