Published online by Cambridge University Press: 12 June 2017
Glyphosate [N-(phosphonomethyl)glycine] and EPTC (S-ethyl dipropylthiocarbamate) did not reduce significantly the percent germination of either ‘Saranac’ or ‘Vernal’ cultivars of alfalfa (Medicago sativa L.) grown in petri dishes. Glyphosate at 10−5 M significantly reduced shoot length of both cultivars. Vernal alfalfa appeared to be more susceptible to glyphosate than the Saranac cultivar. Soil applications of glyphosate also had no effect on percent emergence of either cultivar and reduced plant height only of Vernal when applied to the soil at 17.9 kg/ha. Applications of glyphosate at 2.2, 4.5, and 9.0 kg/ha to a Kentucky bluegrass (Poa pratensis L.) sod in a simulated sod seeding alfalfa establishment study in the greenhouse reduced dry weight of both alfalfa cultivars; Vernal was affected more adversely than Saranac. Application of 2.2 kg/ha glyphosate in four management systems showed that a 3-day planting delay after spraying reduced growth inhibition of alfalfa seeded in treated sod. These results were similar to those obtained with paraquat (1,1′-dimethyl-4,4′-bipyridinium ion) in these management systems. Kentucky bluegrass clippings treated with paraquat 3 days or less before contact with alfalfa seedlings significantly reduced seedling dry weight. Clippings treated with glyphosate did not reduce alfalfa seedling dry weights significantly.