Efecto de inyecciones nutritivas al tronco en la productividad de naranja valencia

The objective of this work was to determine the effect of nutritional trunk injections (NI) of N, [P.sub.2][O.sub.5], [K.sub.2]O, CaO, and MgO on quantitative and qualitative productivity. Experimental trials were conducted during three years, between campaigns 2008/09, 2009/10 and 2010/11, in an orchard of orange "Valencia Late" in Corrientes, Argentina. NI were applied to each side of the trunk at 40 cm of soil. The treatments tested consisted of soil fertilization (50% spring and autumn) T1: 1,5 kg [plant.sup.-1] of 15-6-15-6 (half dose, HF); T2: HF treatment plus NI spring; T3: HF plus NI spring and summer; T4: HF plus NI spring, summer and autumn and T5: full dose 3 kg [plant.sup.-1] of 15-6-15-6. Statistical design was a randomized complete block with four replications, experimental plot of two effective plants. Leaf concentrations of N, P, K, Ca, Mg, Fe, Zn, Cu and Mn were determined in leaves of fruiting branches obtained in autumn. Total fruit production was measured at harvest, diameter, percentage of juice, soluble solids contents, acidity, ratio and color were determined on a sample of 40 fruits per plot. Variance analysis, Duncan test and principal component analysis were done for quantitative variables and for color Kruskal Wallis test was performed. Fruit production was increases by the treatment 4 compared with same dose of soil applications (T1) added that none of the treatments significantly affected IN fruit quality. This report establishes the utility of using the IN as a complementary tool to conventional fertilization. Key words: citrus hybrids, fertilization, sensory fruit characteristic, yield Se determinó el efecto de inyecciones nutricionales al tronco (IN) de N, [P.sub.2][O.sub.5], [K.sub.2]O, CaO y MgO en la productividad de naranja "Valencia Late" en Corrientes, Argentina. Durante tres años, campañas 2008/2009, 2009/2010 y 2010/2011, se llevaron a cabo ensayos experimentales aplicando diferentes dosis de IN a cada lado del tronco a 40 cm del suelo. Los tratamientos evaluados consistieron en la fertilización al suelo (50% en la primavera y en otoño) T1: 1,5 kg [planta.sup.-1] de 15-6-15-6 (media dosis, MD), T2: tratamiento MD más IN en primavera; T3: MD más IN en primavera y en verano; T4: MD más IN en primavera, en verano y en otoño y T5: dosis completa de 3 kg [planta.sup.-1] de 15-6-15-6. (DC). El diseño experimental fue de Bloques al Azar con cuatro repeticiones y parcela experimental de dos plantas efectivas. Se determinaro