THE EFFECT OF TILLER SIZE IN AUTUMN ON THE PERCENTAGE OF REPRODUCTIVE TILLERS IN AMENITY TYPES OF POA PRATENSIS L., FESTUCA RUBRA L. AND LOLIUM PERENNE L.

B. Boelt

Danish Institute of Agricultural Sciences, Department of Plant biology

Research Centre Flakkebjerg, DK-4200 Slagelse, Denmark

e-mail: birte.boelt@agrsci.dk

A field experiment was initiated to assess the effect of tiller size in autumn on the percentage of tillers that survived the winter and produced an inflorescence in amenity types of smooth stalked meadow grass (Poa pratensis L.), red fescue (Festuca rubra L.) and perennial ryegrass (Lolium perenne L.). Tillers were labelled according to stem base diameter in three categories with intervals being > 2.0 mm, 1.5-2.0 mm and 1.0-1.5 mm.

The highest percentage of reproductive tillers was recorded in perennial ryegrass, where on average 93% of the tillers present in autumn produced an inflorescence. However, in all the species smaller tillers had a lower percentage of reproductive tillers. This effect was quite pronounced in smooth stalked meadow grass that only approximately 50% of the small tillers (1.0-1.5 mm) present in autumn produced an inflorescence.

Keywords: Smooth stalked meadow grass; red fescue; perennial ryegrass; stem base diameter; fertile tillers.