The problem of assessing strains: A study in grass-breeding technique

Abstract

1. This paper reports a study of the behaviour of five strains of ryegrass (Devon Eaver, Irish S. 24 and New Zealand certified mother perennial ryegrass and H.I) under three different conditions of spacing and two types of management. Strain performances are compared on the basis of green and dry-weight data of total herbage, and green weight of sown strain contributions under the three techniques of evaluation.2. Under both managements, the total annual production per unit area was greatest from broadcast and least from single-plant areas. Some individual cut yields were, however, greater than those from broadcast plots, with the drill-row production intermediate.3. Yield differences between the four perennial ryegrasses were greatest as spaced plants and least in broadcast plots. Single plants and broadcast plots of H. 1 were outstanding compared with the perennial strains. Under neither management were there significant interactions between strains and sowing method in 1952, though such interactions were detected in both cases during 1953.4. The relative yield performance of strains under similar spacing conditions were almost identical under both managements.