ABSTRACT
Elevated atmospheric C 0 2 concentrations and associated climate changes may affect crop production in coming decades, as well as world food supplies (Rosenzweig and Hillel, 1998). During the latter part of the twenty-first century, crops are expected to be grown in en vironments with twice the present atmospheric C 0 2 concentrations, with average temperatures being about 2 to 5°C warmer than at pres ent (Houghton et al., 1996). In addition, unexpected late springs and early frosts and periodic episodes of heat and drought stresses are predicted to occur more frequently under new weather environments, and changes could exacerbate climate effects on many aspects of crop growth and development to decrease crop yields and quality (Reddy etal., 1999).
