RENDIMIENTO POTENCIAL EN HÍBRIDOS DE MAÍZ LIBERADOS EN ARGENTINA ENTRE 1965 Y 2010.

DI MATTEO, J.; CERRUDO, A.; ECHARTE, L.; ANDRADE, F.H.

Rosario

Congreso; Maíz HD-X Congreso Nacional de maíz; 2014

Average crop yield increased around 116 kg ha-1 year-1 between 1965 and 2010 in Argentina. In Argentina, yield potential increased around 150 kg ha-1 yr-1 from 1965 to 1997. Argentine hybrids released in the 1990s yielded more than hybrids released in the 1960s in a wide range of plant densities tested; but it is not known if the optimum plant density was increased across the decades. Additionally, it is important to extend the period analyzed of yield potential for hybrids released in Argentina. The objectives of this work were to determine (i) the optimum plant density, and (ii) the potential yield increment, its physiological determinants (i.e. seasonal shoot biomass and harvest index), and numerical components (i.e. kernel number and weight per kernel), for hybrids released between 1965 and 2010. Field experiments included hybrids released between 1965 and 1993 (Exp. 1 and 2), hybrids released from 1993 to 2010 (Exp. 3 and 4) and hybrids released from 1965 to 2010 (Exp. 5). Plant densities ranged from 1.5 to 20 pl m-2.  The optimum density was estimated using a modification of the methodology proposed by Sarlangue et al. (2007). The optimum density to attain the maximum yield was similar across hybrids released in different decades (P=0.069). The potential yield increased around 0.73% year -1 (P<0.0001) which represents 110 kg ha-1 year-1. However, the harvest index increased only from 1980 to 1993 and remained stable at 0.52 from 1993 to 2010. Biomass production increased around 0.31% year-1 (96 kg ha-1 año-1) steadily thought the decades. Kernel number increased around 0.86% year-1 (53 kernels m-2 year-1) while the weight per kernel was stable across the decades.