Gabriela Elba Senisterra

Variation of wood Density and fibre length in six Willow Clones (Salix SPP.)

The variability of wood basic density and fibre length was determined in six 13-year-old willow clones growing under two different site conditions in Argentina. Values of basic density and wood fibre length were obtained and variance analyses were performed considering site and clone as sources of variation. Components of genetic and phenotypic variations were determined to calculate heritability in the broad sense. Site influence was significant for basic density, which ranged from 0.364 kg/dm3 and 0.455 kg/dm3. Clones “americano” and hybrid cv “A 13-44” showed the highest density values in both sites. For fibre length, values of the continental site were significantly higher. For each clone, mean values vary between 837.1 μm and 1142.1 μm. Heritability values show that the genetic control is stronger for density (h2 = 0.65) than for fibre length (h2 = 0.32). The clones “americano” and “13-44” stand out because of their high density and long fibres.

Estimation of soil erosionability in the stream basin of Pillahuinco Grande, Province of Buenos Aires, Argentina

2correlation value was 0.76 in relation to the simplifi ed K factor, 0.87 to K1, and 0.86 to K2 (very similar due to the small signifi cance of silt in the equation). This relationship demonstrates that the application of K1 and K2, according to the readiness of the data, is more specifi c and exact than the results obtained by applying the simplifi ed K factor.