Biblio
“The relationship between applied nitrogen, nitrogen concentration in herbage, and seed yield in perennial ryegrass (Lolium perenne L.). II. Cultivars in Oregon”, J. Appl. Seed Prod, vol. 16, pp. 115–124, 1998.
, , “The link between nitrogen application, concentration of nitrogen in herbage and seed quality in perennial ryegrass (Lolium perenne L.)”, J. Appl. Seed Prod, vol. 17, pp. 1–6, 1999.
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