In agronomy and seed production, seed uniformity defines their homogeneity in size, most often thickness, which influences sowing quality. Crop uniformity characterizes the homogeneity of the plant stand in terms of height, phenological stage timing, and general plant habitus, which is important for the efficiency of mechanical harvesting.
During laboratory seed analysis, the indicator is expressed as a percentage representing the sum of the two most representative adjacent fractions. In variety testing, plant uniformity is evaluated visually or through the coefficient of variation of morphological traits. The lower the coefficient of variation, the higher the level of variety uniformity is considered to be.
The level of this trait depends on both the genetic characteristics of the variety and environmental conditions, including agronomic practices and meteorological factors during the seed formation period. Material with a uniformity of at least 80% is considered standard, and values below this threshold require mandatory calibration of the lot before sowing.