The interaction between wheat and perennial ryegrass seed density and seedlings of different ages was studied under controlled conditions. Root length of perennial ryegrass, after sowing, was suppressed by wheat and was dependent on the density of wheat seeds. Shoot growth of perennial ryegrass, however, was unaffected by the presence of wheat. Perennial ryegrass density had no effect on the first 2 wk of wheat seedling growth. The age of wheat seedlings had no appreciable influence on either root or shoot growth of perennial ryegrass. The present study highlights the need for an unbiased two-way experimental design to identify the dominant competitor.
Nomenclature: Perennial ryegrass, Lolium perenne L. #3 LOLPE; wheat, Triticum aestivum L.
Additional index words: Allelopathy, competitive ability.
Abbreviation: ANOVA, analysis of variance.