FIELD: agriculture.SUBSTANCE: method involves determining weather values at a specified measurement period from a sowing point to a time point within the earing phase to the yellow ripeness phase； separation of measurement period into time intervals corresponding to duration of phenological phases； dividing the measurement period into time intervals and using a coefficient which takes into account the different effect of the phenological phases. At the first phenological phase "sowing – sprouts" soil temperature and moisture are measured, and on the remaining phenological phases of plants development – air temperature and soil moisture. Duration of time intervals is reduced to two days. Angle, which characterizes area of effective usage of weather factors by plant for each phenological phase for realization of growth process, is defined as the angle between the temperature axis and the vector passing from the origin to the point, which for the first phenological phase corresponds to the optimum values of temperature and soil moisture, and for other phenological phases corresponds to optimal values of air temperature and soil moisture, using for this purpose at the specified scale of axes the graphic constructions of the previous experimental investigation, which detects by means of residual method above specified optimum values on temperature and moisture on various phenological phases. Crop yield is evaluated by formula:, where n is number of time intervals during measurement period； n1 is the number of time intervals throughout 1st phenological phase； ni is number of time intervals during i-th phenological phase； l is number of analyzed phenological phases； i is number of analyzed phenological phase； j is number of time interval during phenological phase； A is conversion coefficient of calculated result to value in "kg/ha"； Kf1 – coefficient of 1st phenological phase； Kfi is coefficient of i-th phenological phase； Bp1j is soil temperature loss at the j-th interval
