Fig. 2. Relationship between stover (a) dry matter yield, (b) crude protein (CP) concentration, (c) neutral detergent fiber (NDF) concentration, (d) acid detergent fiber (ADF) concentration, (e) in vitro true digestibility (IVTD) concentration, and (f) ear/stover ratio and growing degree units (GDUs). Each data point is the mean across four hybrids, four replicates, and 2 yr. Equations and coefficients of determination (R²) for Fig. 2 are reported in Table 3. R1 refers to the growth stage of the corn when silks were emerged on at least 50% of the plants.