Alkaloids and Palatability of Phalaris arundinacea L. Grown in Diverse Environments1

We grew 15 clones of reed canarygrass (Phalaris arundinacea L.) of varying palatability in Indiana and Minnesota and nine clones in Pennsylvania and Alaska over a 2-year period to determine whether diverse environments would influence alkaloid type, alkaloid concentration, and palatability. We also determined the repeatability of a previously-established correlation between palatability and total basic alkaloids in reed canary. Major alkaloid types and relative total basic alkaloid concentrations of clones were very repeatable among locations, even though heat units and daylength varied greatly. Of the nine clones grown in all 11 environments, three always contained gramine (3-dimethylaminomethyl-indole), two contained N,N-dimethyltryptamine, and four contained 5-methoxy-N,N.dimethyltryptamine. Total basic alkaloid concentrations of clones were highly correlated (r = 0.90 or higher) between all combinations of environments. Palatability ratings of clones grazed by sheep were highly correlated between Minnesota and Indiana (r = 0.91 or 0.96) and between harvests within locations (r = 0.97 or 0.99). Therefore, palatability was a function of plant rather than of animal differences. Total alkaloid concentrations and palatability ratings of clones were highly correlated (r = 0.87 to 0.94) when palatability was rated on a scale of 1 (completely consumed) to 10 (completely rejected). These results confirmed previous findings and substantiated the conclusion that determination of total alkaloids is a valid method of screening for palatability in reed canary.