MAIZE WATER USE EFFICIENCY: BREEDING EFFECTS ACROSS CONTRASTING ENVIRONMENTS

CURIN, F.; GONZALEZ, F.G.; SEVERINI, A.D.; OTEGUI, M.E.

Pergamino

Congreso; XI Congreso Nacional del Maíz; 2018

AIANBA

Maize (Zea mays, L.) grain yield (GY) progress is well below the projected as necessary to meet the expected global demand. Argentina records are close to global reports for mean GY, although the potential productivity is much higher. Main determinants of this gap are nutritional and water deficits. The former can be corrected by fertilization. Breeding is among the few technologies aimed to alleviate the latter in rainfed farming. The aim of our study was identify breeding effects in relation to water use and water use efficiency (WUE). Five hybrids (H) released during the last four decades were sown in eight different environments (E) at three stand densities (SD). Measurements included crop evapotranspiration (ETC) and shoot biomass (BT) at harvest. Radiation use efficiency (RUE) and WUE were computed. Significant hybrid and E×SD effects were detected for both efficiencies, but neither SD×H nor E×H effects were found. ETC declined for hybrids release after 1993. WUE and RUE increased throughout the evaluated period. Results suggest that maize breeding in Argentina had a larger effect on canopy traits that affect RUE (0.5 % year-1) than on root traits that affect ETc (-0.4% year-1) and WUE (0.4% year-1).