Contribución de las jerarquías tempranas de plantas a las respuestas del cultivo de maíz a la fertilización nitrogenada

MADDONNI, GUSTAVO A.; OTEGUI, MARÍA E.; ROSSINI, MARÍA DE LOS ANGELES

Corrientes

Congreso; XXXI Reunion Argentina de Fisiologia Vegetal; 2016

Sociedad Argentina de Fisiología Vegetal

The aim of this study was to analyze (i) the contribution of early established plant hierarchies (dominated, mean and dominant) to crop responses to N fertilization in terms of biomass, grain yield, total and grain N uptake (NUP,) of two maize hybrids with different tolerance to crowding stress, (ii) changes among hierarchies in N use efficiency to produce biomass (NUEBIOM) and grain yield (NUEGRAIN), and (iii) the impact of inter-plant variability of NUEGRAIN on NUEGRAIN at the crop level. Crop responses to N fertilization of tolerant hybrid were mainly caused by the response of the early-established mean and dominated plants. These responses denote differences in NUEBIOM and NUEGRAIN among plant hierarchies. Inequity among hierarchies contribution was lower in the intolerant hybrid. N fertilization attenuated inter-plant variability in NUEGRAIN in a larger extent in the tolerant hybrid. The NUP in excess by dominant plants (mainly in the intolerant hybrid) was accompanied by a fall in crop NUEGRAIN, which was negatively associated with population variability in NUEGRAIN.