Tiller dynamics, growth, and persistency of Lolium perenne L. and of Lolium rigidum Gaud.

Abstract

Changes in the size and composition of the tiller populations of single plants (20 cm spacing) of summer-dormant and non-dormant types of L. perenne and of L. rigidurn have been determined at Adelaide over a 13 month period. Dry matter yield, summer survival of plants and tillers, and the degree of reproductive development were also recorded. A seed vernalization technique was used in an attempt to obtain developmental variation within each species or cultivar.

The role of vegetative tillers in summer survival was found to be extremely small, since less than 10% of the visible vegetative tillers present at the commencement of summer regrew the following autumn. Regrowth after summer came principally from axillary buds at the base of the fertile tillers. The interrelationships between summer dormancy, regrowth, and tiller ecology are discussed.

The vernalization treatment resulted in increased dry weight and tiller number per plant during the first growing season: with autumn planting it had no marked effect on time of heading, but in some cases increased the proportion of fertile tillers.