Tiempos térmicos a floración y fotoperiodo ante cambios en la fecha de siembra en dos híbridos de maíz

70. GIMÉNEZ, V.D.; CIANCIO, N.; MADDONNI, G.A

Rosario

Congreso; X Congreso Nacional de Maíz; 2014

AIANBA

Grain yield of maize crops is highly determined by the date of sowing. In temperate environments of Argentina, potential grain yields are reduced as sowing date is delayed. However, during the last growing seasons, the proportion of late-sowed maize crops has increased significantly. The aim of this study was to characterize the effect of sowing date on the time to anthesis of two maize hybrids, focusing the study in the response of total leaf number per plant and the rate of leaf appearance to photoperiod and temperature. The experiment was conducted at the field of FA-UBA during 2013-2014. Two commercial hybrids (H1 and H2) were sown on Oct 22, 2013; Dec 11, 2013; Jan 9, 2014 and Mar 10, 2014. Ten plants per plot were tagged to record weekly the number of leaves per plant and the date of anthesis. Duration of the cycle was expressed in thermal time (TT) units after seedling emergence with a base temperature of 8°C. Both TT to anthesis (TTa) and total leaf number per plant varied significantly (p