Survival Characteristics of Corn Seed during Storage: II. Rate of Seed Deterioration

Abstract

The Ellis‐Roberts deterioration model depends on the assumption that the rate of seed deterioration is the same among seed lots of a crop species when stored in identical environments. The rate of deterioration of 11 corn (Zea mays L.) seed lots from six hybrids was measured during storage in various combinations of constant temperatures (20, 30, 40, and 50°C) and seed moisture contents (100, 120, 140, and 160 g kg−1, fresh weight basis). The seed‐survival curves were constructed by conducting successive germination tests at frequent intervals during storage. The rates of seed deterioration were estimated by probit analysis and differences among seed lots were identified by analysis of variance. The deterioration rates were significantly different among seed lots in 16 of 21 storage environments when analyzing full data sets (all data points) and in 14 of 21 storage environments when using truncated data sets (germination percentages between 5 and 95%). Both genotype and initial seed quality affected the rate of deterioration with low‐vigor seed lots generally deteriorating at a faster rate than high‐vigor seed lots. The rate of deterioration was greatly influenced by storage environment and increased with an increase in storage temperature, seed moisture, or both. The assumption of a constant rate of seed deterioration in identical storage environments was not valid for hybrid corn seed.