Abstract
Physical characteristics measured individually for each lettuce (Lactuca sativa L.) seed and its embryo were significantly correlated with seedling and plant growth (vigor) up to a certain stage, possibly heading, after which the correlations diminished. Embryo physical measurements, although slightly better correlated with subsequent vigor than seed (achene) physical measurements, were highly correlated with those of the whole seed.
Of the 5 physical measurements studied, all but length were found to be associated with early vigor. Thorough statistical analyses place seed and embryo physical characteristics in a consistent and significant order in determining vigor: weight > thickness > density (as measured by an air column) > width > length.