%0 Journal Article %T CORRELACI¨®N ENTRE PROPIEDADES ANAT¨®MICAS, RESISTENCIA A FLEXI¨®N EST¨¢TICA Y ENERG¨ªA REQUERIDA PARA EL CORTE DE LA CA A DE AZ¨²CAR (Saccharum officinarum L.) CORRELATIONS AMONG ANATOMIC PROPERTIES, BENDING RESISTANCE AND ENERGY REQUIRED TO CUT SUGAR CANE (Saccharum officinarum L.) %A Hugo Alberto Gonz¨¢lez S¨¢nchez %A Alejandro Toro Betancur %A Fernando ¨¢lvarez Mej¨ªa %A Elkin Alonso Cort¨¦s Mar¨ªn %J Revista Facultad Nacional de Agronom¨ªa, Medell¨ªn %D 2008 %I Universidad Nacional de Colombia, Sede Medell¨ªn %X La microestructura, estructura anat¨®mica, la resistencia a la flexi¨®n y la energ¨ªa requerida durante el corte de los tallos de tres variedades de ca a de az¨²car cultivadas en el Valle del Cauca (Colombia), fueron estudiados con el prop¨®sito de adquirir informaci¨®n ¨²til para el desarrollo de cuchillas para corte de esta especie. Las labores de caracterizaci¨®n microestructural y anat¨®mica se apoyaron en las t¨¦cnicas de microscop¨ªa ¨®ptica y electr¨®nica de barrido. Las propiedades mec¨¢nicas se determinaron adaptando algunas normas ASTM para maderas, mientras que la energ¨ªa al corte se evalu¨® usando un p¨¦ndulo de impacto tipo Charpy modificado. En los tallos de las tres variedades estudiadas se observaron diferentes distribuciones y dimensiones geom¨¦tricas de las fibras y se verific¨® la presencia de part¨ªculas de s¨ªlice. Se present¨® en general mayor requerimiento de energ¨ªa espec¨ªfica al corte en los entrenudos que en los nudos y un menor consumo espec¨ªfico de energ¨ªa al corte con las cuchillas con ¨¢ngulo de afilado de 20¡ã. Se establecieron relaciones entre la microestructura de los tallos, comportamiento a la flexi¨®n y al corte, destac¨¢ndose la relaci¨®n proporcional entre el ¨¢rea transversal efectiva de fibra (ATEF) y la energ¨ªa espec¨ªfica al corte, as¨ª como entre el coeficiente de flexibilidad y el m¨®dulo de elasticidad en flexi¨®n. The microstructure, anatomical structure, bending resistance and the energy required to cut stems of three varieties of sugar cane cultivated in the Valle del Cauca ( Colombia ), were studied in order to have useful data for the development of cutting blades. Microestructural and anatomical characterization tasks were performed by optical microscopy ( OM), and scanning electron microscopy (SEM). The physical and mechanical properties were determined after adaptation of ASTM standards (which were developed for wood), while the consumption of energy during cutting was evaluated by using a modified Charpy type impact pendulum. The fibers and silica particles showed different geometry and distribution in the stems of the three studied varieties, and a relation was established between the microstructure of the stems and the energy required to cut them in the modified Charpy pendulum. Generally speaking, cutting the internodes required higher specific energy than cutting the nodes, and the use of blades with cutting angle of 20¡ã led to lower levels of energy consumption. Also, a relation of proportionality between the effective cross-sectional area of fibers (ATEF) and the specific energy consumed in cutting, as well as between the fl %K Tallos de ca a de az¨²car %K propiedades mec¨¢nicas %K energ¨ªa al corte %K caracter¨ªsticas anat¨®micas %K microestructura %U http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0304-28472008000200023