Characterization of three naturalized grass species of the Dominio humedo de Chile
1993
Balocchi L, Oscar | Lopez C, Ignacio | Nahuelhual M, Laura | Estai M, Adolfo (Universidad Austral de Chile, Valdivia (Chile). Fac. de Ciencias Agrarias)
Three naturalized grass species widely distributed in the Dominio humedo de Chile were collected and characterized. They correspond to Agrostis tenuis, Holcus lanatus and Bromus unioloides. Vegetative tillers were transplanted into experimental plots to study phenologic development, seed germination and seedling vigour. Physical features of the seed such as size, weight and viability were also determined. The germination test was carried out under controlled conditions of temperature, light and moisture. The test lasted between 14 and 28 days in accordance with the requirements of each species. Simultaneously, the effect of two pregerminative treatments (precooling of seeds at 4 for 7 days and a 0,5% solution of potassium nitrate at the substrate) were tested. Bromus unioloides showed the greater percentage of germination (greater than 95%), and seedling development throughout the germinative process. Agrostis tenuis presented the smaller percentage of germination (50% as average) and a high percentage of latent seeds. Holcus lanatus showed an intermediate performance reaching a final germination great then 75% and a low percentage of latent seeds. Only the pregerminative treatment with potassium nitrate had significant effect upon the germination of Agrostis tenuis. The seedling vigour study lasted for 62 days. Growth and development of the three species was compared with Dactylis glomerata, as control. At the end of the period, the accumulation of dry matter in leaves and roots, and the lamina/sheath ratio were measured. Bromus unioloides showed the greater growth rate, expressed as dry weight of leaves and roots per plant per day. Agrostis tenuis showed the smallest growth rate, but with a better lamina/sheath ratio
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