Genetic Variability in In Vitro Dry Matter Digestibility of Fall‐Saved Reed Canarygrass, Phalaris arundinacea L.1

Abstract

Variation in percentage of in vitro digestible dry matter (IVDDM) in fall‐saved forage from 20 reed canarygrass (Phalaris arundinacea L.) clones and their topcross progenies was studied under two clipping managements. Significant differences were found among parent clones in all tests and among their progenies (at .01 and .10 probability levels) in two of three tests. Broad‐sense heritabilities ranged from 51 to 80% among clonal means and from 6 to 66% among progeny means. Significant parent‐progeny correlations also indicated the presence of heritable variation in IVDDM. The correlation between parent and progeny means over years and clipping managements was .69. Average percentage IVDDM decreased from 65 to 55% with an increase from two to three months in length of regrowth period in 1964. The interaction of clones or progenies with length of regrowth period was not significant. A highly significant clone ✕ year interaction indicated that selection should be based oil more than one year's results.Correlations between IVDDM and yield of dry matter, percentage dry matter, percentage crude protein, and palatability score were low and not significant. All correlations with yield were negative and those with percentage crude protein were positive.