Cambios en el índice de verdor en respuesta a la disponibilidad de nitrógeno y densidad de siembra de tres híbridos de maíz

Nitrogen (N) deficiencies and changes in plant population can affect resource availability per plantin maize. Leaf N determination is usually obtained measuring the relative content of chlorophyll inleaves through a green index (VI). In the present work, we analysed the behaviour of three maizehybrids with different prolificacy, at different plant populations and with the application ofdifferent N rates. The experiment was carried out in Balcarce on November 31 and was arrangedin split-plot design, with three replications. The genotype was used as the main plot: H1, H2 andH3. The subplots were four densities and three N doses. VI measurements were carried out atV10, R1 and R4 stages. Yield of each plot was obtained by harvesting the two central rows of eachtreatment. Yield decreased at high densities due to drought at silking. Increases in N ratesincreased yields in all hybrid and density combinations. Changes in IV caused by increases indensity or decreases in N availability were of similar magnitude between treatments and behavedadditively in advanced stages of the crop. Finally, as crop development advanced, differences in IVbecame more notable, but in R1 IV varied according to changes in N rate. Fil: Martínez, Roberto Dionisio. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina Fil: Stadler, Nicolas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina