TEMPERATURAS EXTREMAS DURANTE EL PERIODO CRÍTICO DE MAÍZ EN EL NORESTE ARGENTINO ANTE CAMBIOS EN LA FECHA DE SIEMBRA

FEDERICO DAVID NALLI SONZOGNI; BELÉN ARACELI KETTLER; NICOLÁS NEIFF; GUSTAVO MADDONNI

Pergamino

Congreso; XII Congreso Nacional de Maíz; 2022

Asociación de Ingenieros Agrónomos del Norte de Buenos Aires (AIANBA)

The aims of this work were: to simulate the occurrence of critical period (CP) of maize cultivated at different sowing dates (SD) in six locations of NE of Argentina, and to quantify events of maximum (TX) and minimum (Tx) temperatures above critical thresholds during the CP. Four thermal indexes were defined: number of days with TX>35ºC and Tx>23ºC (DTX+35 and DTx+23, respectively), and cumulative degrees above both thresholds (STX+35 and STx+23 for TX and Tx, respectively). Early (Aug-10 to Sep-10) and late (Jan-10 to Feb-10) SD had longer CP durations (30 and 29d, respectively; averaged between locations) than intermediate SD (24d). Among locations, CP were longer at higher latitudes. The intermediate SD (Oct-10 to Dec-10) always shown the greatest thermal indexes values. Regardless the SD, Las Breñas (Chaco) was the location with the greatest DTX+35 and STX+35 values, meanwhile Las Breñas and El Colorado (Formosa) exhibited the highest DTx+23 and STx+23 values. In summary, early or late SD could mitigate the incidence of extremely high temperatures during the CP of maize crops in the NE of Argentina. Future studies should combine this information with the incidence of water stress during PC and the occurrence of early frosts during the grain-filling period.