Some aspects of competition between timothy and perennial ryegrass : A thesis submitted for the degree of Master of Agricultural Science and Honours in Agricultural Botany

Abstract

The Problem : When timothy occurs in a sward in association with perennial ryegrass the ryegrass frequently appears to be antagonistic to the normal growth of timothy. The outcome of this apparent incompatibility is expressed in reduced tillering and lowered dry matter production by the timothy during the first two or three years of the life of the sward. Thereafter timothy may become one of the major constituents of the sward or remain in a continued state of low productivity depending upon soil conditions and management. The Aim : The primary object of the investigation was to study the extent of the suppression of timothy by perennial ryegrass and to examine the influence of shading and the possibility of excretion of toxic substances by perennial ryegrass as causative agents.