Effects of Seed Vigor on Crop Characters in Uniform and Reduced Populations of Corn (Zea mays L.)

Abstract

AbstractThe relationship between seed corn vigor and some crop characters in uniform and reduced plant populations is poorly defined. This study, was designed to define the crop characters through which seed vigor is expressed in reduced and uniform populations of corn and to clarify which experimental technique should be used in seed vigor studies. Seeds of two corn hybrids, A632 x (H99 x H95) and B73 x (H99 x H95), were dried at two temperatures, 35 °C and 50 oC, and planted near Ames, Iowa, in 1983. The two drying temperatures created differential vigor levels between the seed lots. There were 21 crop characters measured in two populations, reduced populations due to lack of seed vigor and uniform population (thinning to stand). Early vegetative growth was influenced by seed vigor, but as the plant aged, the influence of seed vigor decreased. Increased early plant height, up to 6 weeks old, small stem diameter, low shoot dry‐matter content, delay in days from sowing to 50 % tasseling and to 50 % silking, narrow penultimate and ear leaf, and reduction in the number of ears and tiller production were observed in the uniform population. The differences in population density due to seed vigor did not have a significant effect on final grain yield inasmuch as plants in the reduced populations were able to compensate completely for missing stands.