Evaluation fo frost damage in seed corn (Zea mays): with special emphasis on seed composition and moisture content

Seed corn (Zea mays L.) producers in the Midwest region of the United States are affected by an early fall frost approximately every five years. The negative effects of frost on seed quality vary according to genotype and thus possibly seed composition. Our objective was to determine the effect of seed composition (oil and protein) and seed maturity on seed viability and vigor of artificially frost-damaged seed. Hybrid seed was produced by using a B73 inbred derivative with varying seed oil and protein content from the USDA GEM (United States Department of Agriculture Germplasm Enhancement of Maize) project as the female parent and IRF 311 as the male parent. Field plots were planted in a randomized complete-block design with two replications in one and two locations in 2008 and 2009, respectively. Ears were harvested at 300 to 350, 400 to 450, and 500 to 550 g H2O kg -1 moisture content. Onehalf of the harvested ears in each range were placed in an artificial frost cycle that mimicked a severe killing frost, and the remainder of the ears served as controls. Seeds were dried, threshed, and stored for 42 or 84 days before evaluating seed viability using the standard germination test and seed vigor using the saturated cold test and soak test. The artificial frost treatment decreased the percentage of normal