Partição de matéria seca de feijão Caupi em função da necessidade térmica.

Abstract

The air temperature is a major enviroimental factor in the development and growth condition of the plants from drought stress does not occur markedly. To assess the effeet of air temperature, it may be the concept of thetmal or degree-days. that is based ou plant response to air temperature, the existence highlighting the basal temperaturas that control growth and crop development. When it is desired to simulate the growth of the plants is essential to quantify the distribution of dry matter formed by different components. Faced with these issues the main objeotive was to estimate the basal temperaturas to quantify the sum of degree davs and model the partitioning of dry matter of cowpea cv. BR3 Tracuateua due to thermal need. Were measured basal temperaturas and degree days accuraulated in the main subperiods of eulture through regular monitoring of the phenology of cowpea due to the climatic regime of the region. Meteorologieal data were colleeted from a station automahcally installed at the end of the experimenta) area. The need was iden.ifted through thermal theory of accumulation of degree-days. It was further established biomass partition and the tnfluence of temperature and irrigaüon and flnally this process were obtained empirieal models. A second experiment was performed at the same locaüon with the same methods of cultivatton and measurement, but about a year after the first, «hich provided data for model vahdatton. The values of biomass partitioning were faced with simulated values observed in the field, the second experiment. Tests were used for validation to assess the preciston and accuracy of the models. The basal temperatures lower and higher were considered and found 9 ° C and 38 ° C respectively and accumulated degree-days for the period extending from getm.nat.on to physiological maturity of cowpea cv. BR3 Tracuateua averaged 1052,96. From the beg.nn.ng of differentiation of the treatments were no significam differences (P <0.01) between treatments and without irrigafion. The models showed the index values of trust (c) greater than 0.90, the values of average roo, mean square error RMSE (10-20), the coneordance rates greater than 0.90, and model efficiency values greater than 0 90. Therefore conclude that the models showed good performance and efficiency with basal temperatures considered the deficiency of water affects the dry biomass of cowpea, but does not influence the displacement of the fraction in the plant parts.