Field Criteria Used in Determining the Vigor of Seed Corn (Zea mays L.) as Influenced by Drying Injury

General agreement does not exist regarding the influence of seed corn (Zea mays L.) vigor on subsequent crop performance. Studies were conducted to determine the characters through which seed corn vigor is expressed, how long the influence persists and the relationship among the characters identified. Seeds of two corn hybrids A632 X (H99 X H95) and B73 X (H99 X H95), dried at 35 °C and 50 °C were grown in the field in each of 2 years and in the growth chamber in Ames, Iowa. A complete range of growth parameters was measured in the laboratory and growth chamber and field. Of these parameters, emergence, emergence rate, plant height, stem diameter, shoot dry matter at 4 and 6 weeks and penultimate leaf length and width were characters found to be influenced by seed vigor. As the plants matured, the influence of seed vigor decreased. Positive and negative relationships were found to exist between some of the characters influenced by seed vigor. However, seed vigor had no influence on yield.