The changing tiller population of spaced Plants of S.170 tall fescue (Festuca arundinacea).
In outdoor pot trials in 1962-4, mean tiller number per tall fescue Plant rose exponentially at first, then more slowly, to reach about 300 by end 1962, fell to about 250 during the severe winter 1962-3, then fell steeply to about 100 in early June. Tiller number per Plant increased rapidly in July, less rapidly in Oct., and reached 500 by end-1963. Few tillers died in the mild winter 1963-4; subsequent changes resembled those in the previous year. 30% of tillers present in early May flowered within 6 weeks and a similar number, of all ages, died without producing an ear. Tillers did not flower at other times of year; there was a 2nd and smaller peak of tiller mortality in Sept. New tillers appeared throughout the year, but mainly during June and July and to a lesser extent in Oct. Some tillers were very short-lived, many died in Sept. of the year they were formed, some lived for almost 2 years, most lived for 1 year or slightly less. Very few tillers flowered in the year they appeared. Patterns of tiller production and death were dominated by flowering. __ R.B.