EFFECT OF BEET VINASSE ON GERMINATION AND SEEDLING PERFORMANCE OF RYEGRASS (LOLIUM-MULTIFLORUM LAM CV BARWOLTRA)

The effect of a concentrated, depotassified beet vinasse (desugared beet molasses) on both germination (in vitro and in soil) and seedling development (in soil) of ryegrass Lolium multiflorum has been studied. Germination and root elongation of the ryegrass in vitro were more negatively affected by vinasse (concentration of 0.15 and 0.5% w) than those of cress (Lepidium sativum). Seedling emergence of ryegrass in pots sown in three different soils (a moderately acid, sandy loam soil, without CaCO3; a red, sandy clay loam soil, 12% CaCO3; and a light yellowish-brown sandy clay loam soil, 30% CaCO3) was, in general, not affected by the application of a moderate dose of pure vinasse (approximately 3 t ha-1) at sowing or 30 days before. Only in the acid soil was seedling emergence significantly (P < 0.05) limited during the first week. The application of vinasse at sowing caused an initial significant shortening (P < 0.05) of the primary roots of ryegrass in the three soils studied (measured at the fourth day). However, plant fresh weights (measured at the thirtieth day) were not affected by this treatment, especially in the calcareous soils. In general, the vinasse application produced beneficial results for ryegrass seedling in the three soils.