Mohammad: I suggest you refer to "Correlation of Five Wheat Growth Stage Scales Used in the Great Plains", USDA, ARS, AAT-NC-7, July, 1983, A. Bauer, D. Smika, A. Black. In the Zadoks scale, 50% anthesis occurs at 65; milk development (assume beginning of grain filling) at 71; maturity at 92. Using the figures and tables in this publication should help you resolve your problems. Al ALBERT WEISS, DEPT. OF AGRICULTURAL METEOROLOGY UNIVERSITY OF NEBRASKA-LINCOLN, LINCOLN,NE 68583-0728 VOICE (402)472-6761, FAX (402)472-6614 E-MAIL [log in to unmask]