A comparison of British and North African varieties of tall fescue (Festuca arundinacea). 4. Tiller production in single plants.
Spaced plants of S170 and the 2 synthetic North African tall fescue varieties Syn I and Syn II were grown in the open during Apr-Dec. 1962. Tillers were labelled at intervals and their life-histories followed. Mean tiller number/plant increased exponentially at first but then more slowly. Initially the North African varieties tillered more rapidly than S170 but after Oct. the reverse was true. No tillers died until July, after which death-rates fluctuated widely, reaching a maximum in Syn II of 1.6 tillers/plant per day during Nov. ; in S170 tiller death never exceeded 0.3 tillers/plant per day. Few tillers flowered, particularly in S170; in Syn I a peak flowering rate of 0.4 tillers/plant per day was recorded during Sept., and a slightly smaller rate in Syn II during Oct. Of tillers produced early in the year when plants were small, many flowered and a small percentage died. Similarly, a larger percentage of primary tillers flowered and a smaller percentage died than of tillers borne elsewhere on the plant. S170 probably tillered more rapidly during Oct. because its leaves expanded less rapidly as temperatures fell. This led to an accumulation of assimilates which were available to aid the expansion of more lateral buds into tillers.-F.A.S.