YIELD AND COMPOSITION OF MONOCULTURES AND MIXTURES OF BROMEGRASS, ORCHARDGRASS AND TIMOTHY

Abstract

The objectives of this study were (a) to determine the relative yielding ability of binary and ternary mixtures of bromegrass (Brotnus inermis Leyss.), orchardgrass (Dactylis glomerata L.), and timothy (Phleum pratense L.); and (b) determine the relative competitiveness of the three species in mixtures. Two experiments were established in 1981 and 1982 and each evaluated for three consecutive production years. Bromegrass was the highest yielding monoculture in both experiments, followed by timothy, with orchardgrass being the lowest. Among mixtures, bromegrass-timothy was the highest yielding and orchardgrass-timothy the lowest. Yields of mixtures generally fell between the yields of the monocultures of the component species. There were, however, two examples of mixtures significantly (P = 0.05) outyielding their highest yielding component monoculture. For the bromegrass-timothy mixture there was a trend towards higher yields than the bromegrass monoculture in the second and third years. Mixtures were generally more competitive against weed invasion than were monocultures. In mixtures, orchardgrass was usually the most competitive of the three species, with its percent composition increasing substantially by the end of the third production year. Bromegrass was intermediate in competitiveness, increasing in percent composition in mixtures with timothy, but decreasing in mixtures with orchardgrass. Timothy was the least competitive, decreasing markedly in all mixtures, particularly those which included orchardgrass.Key words: Orchardgrass, bromegrass, timothy, forage grass mixtures, interspecific competition