Air temperature, maize yield and phenological characterization associated to heat units [Temperatura do ar, rendimento de grãos de milho e caracterização fenológica associada à soma calórica]

Abstract

With the purpose of evaluating the effect of the mean daily air temperature on grain yield and to predict the occurrence of the maize crop phenological phases as function of heat units, a field experiment was carried out using three hybrids with different heat unit requirements and three sowing dates. To estimate grain productivity, different yield components were determinated. Crop phenology was associated to the relative degree-days, for which a linear relation was observed. There is a mean air temperature corresponding to maximum grain yield, and the crop phenological phases can be predicted knowing the local historical temperature series and the thermic index for physiological maturity. © 2000, Scientia Agricola. All rights reserved.