The effect of the time of seedling emergence of crisp lettuce on the time of maturity and head weight at maturity

SummaryThe effect of the time of seedling emergence on the time of maturity and the head weight at maturity of the American crisp lettuce cvs Salinas and Pennlake was examined using crops sown in April, May and July. Within a crop, later emerging seedlings of both cultivars produced plants which matured later. There was a trend towards later emerging seedlings producing lighter heads though the opposite was true for Salinas sown in May. These results suggest that, within a crop, variation in the time of maturity and in head weight at maturity can be reduced by improving the uniformity of seedling emergence.