Abstract
Mass selection for quick and slow emergence within a population of alfalfa, composed of 10 very winter-hardy cultivars and strains, was accompanied by an increase in yield of the quick emerging population over that of the slow emerging population. Combined selection for rate of emergence in two directions, followed by selection on the basis of high and low yield in the respective populations, caused a differential of about 10% in yield between the two. This yield differential appeared to hold in the field as well as in the greenhouse. It is suggested that selection for quick and slow emergence could effect a change in the population for more or less yield and less or more persistence.