Abstract
Three experiments were conducted with seedlings of Lolium multiflorum (mammoth, 4n) grown in 1/5000 a pots filled with the mixture of vermiculite, sand and clay soil with the ratio of 2, 2 and 1 in bulk followed by fertilizer application 10g/m^2 each of N, P_2O_5 and K_2O as base, to confirm the timelife of roots during establishment and to find the contribution of seminal roots for early growth. 1. Seedlings were sampled every fortnights for spring-sown experiments and every eighth day for autumn-sown samples. Roots were graded into three categories according to visual observations with respect to their morphological development and appearance of senescence. New roots were enamelled at their bases every eighth day with different colours to visualize their history. 2. Effects of fertilizer application to seminal roots and/or nodal roots were compared upon the seedling growth. 3. Either of the roots were pruned from their emergence in one experiment and in another experiment seminal roots were pruned from the date of root emergence until the eleventh day by two-day intervals to confirm whether these treatments give any harmful effects on early growth. It was found that both roots proceed to grow until five weeks after emergence and will stop growing during next one or two weeks. They seemed to begin to decay around that date at their tips. Roots of spring-sown grasses seemed to have a shorter life than those of autumn-sown grasses. Seminal roots will continue to grow and work until seventh week after seeding far beyond the weaning stage. It plays an important role in absorption and anchoring particularly until two weeks after seeding.
