How uniform is emergence and early growth, and does seed matter?
In many fields, uniformity of emergence and plant size early in the season probably reduce yields more than does non-uniformity of plant spacing. Planting depth is one factor that affects uniformity of emergence. The ideal depth may vary some depending on soil conditions, but in most cases planting 1.5 to 1.75 inches deep is likely to provide the best results. Both deeper and shallower planting tend to place seed in less-uniform conditions, which can contribute to unevenness in emergence time or stand loss. If planting is done under reasonably good conditions, emergence in a field should normally take place over a period of less than 48 hours. In a study we did using a seed coating designed to delay emergence, yield decreased when the time to emergence was delayed and the number of days between first and last emergence was increased (table 2). It is not possible to separate the effects of emergence timing and uniformity in this study, but there is other evidence that non-uniform emerge
