Merit evaluation of perennial ryegrass cultivars following wear.

The visual merit of 49 Lolium perenne cultivars was scored at the end of football type wear by 9 assessors in Apr. 1989. Spearman's rank correlation coefficients (rs) were calculated to compare scores of each individual with ground cover deduced by point quadrat, shoot density, height, leaf width and reflectance ratio (near infra red:red). The point quadrat and reflectance ratio assessments were most closely correlated with visual merit. Reflectance ratio measurements during the time of visual assessments were not as closely related to visual merit as were measurements in an assessment conducted in Mar. The rs for shoot density against visual merit varied considerably amongst individuals. Rate of growth was positively correlated with visual merit and ground cover. Leaf width was negatively correlated with shoot density but was not significantly associated with any other measurement.