Legume Compatibility of Reed Canarygrass Clones Related to Agronomic and Other Morphological Traits

Abstract

Legume compatibility, the ability of a forage grass genotype to persist in a legume mixture without losing the legume stand, is needed in genetic materials intended for use in perennial grass‐legume mixtures, but limited information exists about appropriate selection criteria for forage grass compatibility with legumes. Data on nine agronomic and morphological traits of 14 reed canarygrass (Phalaris arundinacea L.) clones grown alone were used to explain their compatibility with alfalfa (Medicago sativa L.) or with birdsfoot trefoil (Lotus corniculatus L.) in binary mixtures subjected to a hay management. A second objective was to choose traits to use as components of a selection index for legume compatibility. Data on the nine traits of the 14 clones grown alone were summarized by principal component analysis. The nine first principal components were then reorganized into three uncorrelated factors, each of which described a different combination of principal components. Clones with high Factor I scores exhibited some combination of high dry‐matter yield (DMY), high tiller weight, early maturity, and height. Clones with high Factor 2 scores exhibited some combination of high DMY, high tiller density, high leaf area per ground area, and low rhizomatous spreading ability. Clones with high Factor 3 scores exhibited some combination of high specific leaf weight, low leaf area per ground area, and erectness of leaves. Factors 1 and 2 were equally important in describing the variability among the 14 clones, and Factor 3 was about 30% less important. Factors 1 and 2 often explained variability for reed canarygrass DMY and legume concentration in alfalfa and birdsfoot trefoil mixtures, but Factor 3 was never significant (P > 0.10). Selection on a spaced‐plant basis for higher DMY, early maturity, increased height, higher tiller density, and lower rhizomatous spreading ability should improve the legume compatibility of reed canarygrass in legume‐dominated stands managed for hay production.