TILLER GROWTH AND DEVELOPMENT CYCLE IN BROMUS INERMIS GROWN FOR SEED IN SOUTHERN MANITOBA

Abstract

Tiller production and development by brome-grass (Bromus inermis Leyss.) grown on Red River clay and fertilized with 207 kg/ha of 27–14–0 in spring, midsummer or late fall were compared at frequent intervals. Seed yields in the range 225–750 kg/ha were obtained. Seed production in 1964 equalled the combined production of 1965 and 1966. Differences due to the addition of fertilizer were not evident until the third harvest year. Growth of the overwintering tillers commenced in April. Jointing started in early May, probably in response to suitable temperatures, and stopped in late August when daylength shortened to less than 15½ hours. During the jointing period, the rosette tiller was an evanescent stage between crown buds and jointed tillers. Shortly after jointing started, the number of crown buds reached a low level. Replacement buds developed during June and July. From early August until growth cessation in late October, new tillers appeared continually from crown buds, and the rosette tiller stage represented a considerable proportion of the tiller population. Deterioration of the bromegrass stand to the "sodbound" condition was accompanied by reductions in tiller density and growth rate. Addition of fertilizer prevented or reduced this deterioration. The time of fertilizer application was not critical.