Vegetative Development of Cesalpinea ferrea and Anadenanthera macrocarpa: I: Estimated of Cardinal Temperatures

Abstract The air temperature influences the vegetative development and the seedling phase duration in the forest species, since it regulates the photosynthesis reactions, because that is considered the main meteorological variable. The aim of this work was to estimate cardinal temperatures (base, optimum and maximum), which determines the thresholds on the development phases, and to estimate the phyllochron of two forest species in the seedling phase. A field experiment was carried out in a completely randomized design, in a 2X12 factorial arrangement, with two Brazilian forest species (Caesalpinia ferrea Mart. ex. Tul. Var. leiostachya Benth e angico-vermelho - Anadenanthera macrocarpa (Benth) Brenan), 12 sowing dates and five replicates. The cardinal temperatures for pau-ferro were: 12.8 °C, 20.7 °C and 46.3 °C and for angico-vermelho were: 10.3 °C, 23 °C and 45.5 °C. The phyllochron was 56.9 °C day per leaf for pau-ferro and was 163.8 °C day per leaf for angico-vermelho, which indicates that angico-vermelho requires more energy accumulation to promote the vegetative development than pau-ferro.