Drought and temperature limit tropical and temperate maize hybrids differently in a subtropical region.

CASALI, L ; ; RUBIO G; HERRERA JM

AGRONOMY FOR SUSTAINABLE DEVELOPMENT

EDP SCIENCES S A

Lugar: Paris; Año: 2018 p. 38 - 49

1774-0746

Although the semiarid and subhumid Chaco regions in northern Argentina have been traditionally consideredmarginal and unsuitable for cultivating grain maize for human and livestock nutrition, this crop is increasingly being adopted by local farmers. The low maize yieldsobserved in the area suggest that climatic constraints limit productivity, while changes in genotypes and management may beuseful to mitigate the effect of these constraints. We analyzed data from 792 farm paddocks withmultivariate mixed models to identify and quantify the main environmental andmanagement constraints to maize?s yield. In addition, we used the crop model CERES-Maize to assess the potential of a temperatemaize hybrid to overcome water constraints.Results from the mixed models identified the amount ofrainfall during February as a primary determinant of maize yield and showedthat tropical hybrids tended to withstand higher temperatures and heat stress better, while temperate hybrids performed betterunder conditions of water scarcity. CERES-Maize simulations suggested that temperatemaize hybrids have the potentialto increase grain yieldsfrom 18 to 21 kg ha-1 (14.5% moisture content) for every mm of rain during February. This report is the first to identify alternative rolesof temperate and tropical maize hybrids for counteracting climatic risks in thestudied subtropical regions. These findings will provideplant breeders urgently needed information to breed better-adapted maize genotypesfor the semiarid and subhumid Chaco.Keywords: farming systems, subtropical semiarid areas, big-data, mixed models, climate change.