An Alternative Model to Predict Corn Seed Deterioration during Storage

Abstract

An assumption of the Ellis‐Roberts viability equation, that all seed lots of a species deteriorate at the same rate in the same storage environment, was not valid for hybrid corn (Zea mays L.) seed. Thus, an alternative model was developed that used a potential storability index (PG, the time for germination to decline to a level G) and a storage environment coefficient (SEC, the factor by which seed longevity is altered by a change in storage temperature and seed moisture content) to predict deterioration of hybrid corn seed. The alternative model was derived from the ratio of seed longevity of the same seed lot in two storage environments. The PG in the storage environment was estimated as the product of PG in a rapid‐aging test and SEC, which was determined with a regression model based on the differences in temperature and moisture between the two environments. The model was evaluated by predicting the time to 90 and 50% germination (P90 and P50) for high‐ and medium‐quality seed lots stored under a range of constant conditions. There was generally good agreement between predicted and observed P90 and P50, with many of the predicted values within 10% of observed values across five seed lots. The storage conditions in the rapid‐aging test had no effect on the predictive ability of the model. This model provides an effective approach to predicting corn seed longevity that may be useful in managing seed storage.