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Figure 3. (A and B) ERA hybrids from the 1930s and the 1990s, respectively, showing differences in leaf angle (Photo courtesy of D.N. Duvick). (C and D) Canadian hybrids at 9 weeks post-silking from the 1940s and 1980s, respectively, showing differences in visual stay-green. (E and F) Maize plants with excess source capacity, relative to sink capacity, which is typified by purpling of leaves and stalks. G. Maize plant with excess sink capacity, relative to source capacity, which is typified by premature senescence of the leaves and stalk. (H and I) Hybrids grown at a high plant population density showing symptoms of nitrogen deficiency and variability in ear size, respectively.
