Author(s)

Emanoeli Borges Monteiro, Cátia Cardoso da Silva, Andréa Carvalho da Silva, Adilson Pacheco de Souza

Institute of Agricultural and Environmental Sciences, Federal University of Mato Grosso, Sinop, Brazil.

This study determined the thermal requirements of forest native seedlings (Hymenolobium petraeum and Parkia pendula) and exotic seedlings (Adenanthera pavonina and Cassia fistula) all belonging to Fabaceae family, in three shading conditions (full sun, 50% and 65% of global radiation attenuation by poliefinas black screens). Also they were estimated of leaf emergence by Phyllochron and the Wang and Engel models, on climatological conditions at Sinop (Region of Transition Amazon-Cerrado), Mato Grosso State, Brazil, for winter period (between June and August of 2012). The minimum (T_b) and maximum (T_B) basal temperatures and the optimum temperature (T_opt) of growth of each species were estimated by regressions between relative growth rates and minimum, maximum and average temperatures, respectively. The values of the estimated T_b were 15.0°C, 16.4°C, 14.5°C and 14.6°C; to T_B were 39.7°C, 37.1°C, 38.6°C and 40.1°C; and to T_opt were 24.4°C, 24.9°C, 24.9°C and 25.1°C to A. pavonina, C. fistula, H. petraeum and P. pendula, respectively. The Phyllochron model showed highest efficiency in the estimation of leaf appearance when compared to Wang and Engel method.

Vegetative Growth, Thermal Sum, Degree-Days, Statistical Indicatives

Monteiro, E. , da Silva, C. , da Silva, A. and de Souza, A. (2014) Estimating Emission of Leaves Seedlings Forest in Different Shading Levels, at Conditions of Transition Amazon-Cerrado, Brazil. American Journal of Plant Sciences, 5, 2330-2341. doi: 10.4236/ajps.2014.515247.