Trends of Wheat Phenological Stages (IMAGE) Science China Press Caption These are trends of wheat phenological stages from 1981 to 2010. (The cross symbol (+) in some circles and triangles indicate that the trend is significant at the 0.05 level. SW: spring wheat; WW: winter wheat.) Credit ©Science China Press Usage Restrictions Use with credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.