A QUANTITATIVE ANALYSIS OF GERMINATION AND EARLY SEEDLING GROWTH IN PERENNIAL RYEGRASS

Seedlings of perennial ryegrass were grown in soil and growth was studied up to 21 days from sowing. The shoot grew exponentially during this period. The weight of the whole plant fell to about 65% of the original weight of the caryopsis at about 9 days from sowing and did not regain this original value until about 16 days after sowing. Endosperm reserves were virtually exhausted within 14 days. The interval between the 7th and 14th day appears to be critical in the establishment of the seedling, when conditions adverse to the development of a rapid rate of photosynthesis by the shoot could severely reduce seedling growth and the chances of survival.