Growth and productivity evaluation of three varieties of sugar cane in two agro-ecological regions of Tucuman-Argentina/Crecimiento y productividad de tres variedades de cana de azucar en dos regiones agroecologicas de Tucuman-Argentina

Sugar industry and sugar cane cropping is one of the main economic and social activities in the northwestern region of Argentina. The goal of this study was to analyze the growth dynamic and productivity of three varieties grown in two agro-ecological regions of Tucuman, Argentina. Two trials were established in different locations where EEAOC's sugar cane nurseries were established (plot 11-15 and Los Trejos). From the beginning of sprout emergence, periodic measurements of stalk population dynamics and stalk height were carried out. At the end of the cycle, cane and sugar yield per hectare (TSCH and TAH) was estimated. Plot 11-15 presented higher tiller population, between 44 and 40 stalks [m.sup.-1] for LCP 85-384 and TUC 97-8 respectively. TUC 95-10 registered 30 stalks [m.sup.-1] in both locations. Final number of stalks per linear meter (FN) did not evidence differences between locations, but a significant interaction location*variety was determined. In this case, LCP 85-384 registered 20 stems [m.sup.-1] in Los Trejos. Individual variables stalk weight showed significant differences between locations and the highest value was observed in Los Trejos even though no significant interaction location*variety was determined. TSCH was significantly higher in Los Trejos where TUC 95-10 produced 113 t [ha.sup.-1], presenting significant differences between the rests of the interactions. TUC 95-10 showed better adaptation to different agro-ecological conditions, presenting high sugar cane yields in both considered regions. Key words: growth, environment, yield, population. La produccion de cana de azucar, en Argentina, tiene una gran importancia economica y social. El objetivo de este trabajo fue analizar la dinamica de poblacion de tallos, la evolucion de la altura y la productividad de tres variedades de cana de azucar (LCP 85-384, TUC 95-10 y TUC 97-8), en dos regiones agroecologicas de Tucuman, Argentina. Los ensayos se realizaron en lotes semilleros de la Estacion Experimental Agroindustrial Obispo Colombres (EEAOC), Lote 11-15 y Lote Los Trejos. Desde el inicio de la brotacion, se midio, periodicamente, la dinamica de la poblacion y evolucion de la altura de los tallos. Al final del ciclo, se determino la produccion de cana y azucar por hectarea. En el Lote 11-15 se registro el mayor macollaje, entre 44 y 40 tallos [m.sup.-1] para las variedades LCP 85-384 y TUC 97-8, respectivamente. Para la variedad TUC 95-10 se registraron 30 tallos [m.sup.-1], en la