Maize water use efficiency: breeding effects across contrasting environments

CURIN, FACUNDO; GONZÁLEZ FG; SEVERINI, ALAN; OTEGUI, MARÍA ELENA

Pergamino

Congreso; XI Congreso Nacional de Maíz; 2018

AIANBA/INTA

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 both mean GY and its percent annual gain, 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 released during the last four decades were sown in eight different environments (E) at three plant densities. Measurements included crop evapotranspiration (ETC) and shoot biomass (BT) at harvest. Radiation use efficiency (RUE) and WUE were computed. Significant hybrid and E×density effects were detected for both efficiencies, but neither density×hybrid nor E×hybrid 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).