Using degree days accumulated by monomodal growth cycles in estimating evapotranspiration of sugarcane (Saccharum spp. hybrid)

Abstract

Presents preliminary results about the relationship obtained among degree days, evapotranspiration and agricultural yields of sugarcane. A linear correlation between evapotranspiration and degrees days accumulated by monomodal growth cycles was obtained. A trial to estimate agricultural yields in seven basic business units (BSU) of Cuba was conducted. Potential yields were determined from the degree days. These ranged from 160,2 to 205,7 t cane.ha-1, indicating the potential possibilities of this crop. In five of the seven companies, used model underestimated farm yields in percentages from 8,52 (UEB �??Jesús Rabí�?� to 28,81 % (UEB Brazil). Agricultural performance was overestimated in two UEB �??Primero de Enero�?� and �??Argeo Martínez�?� at 8,20 and 13,98 %, respectively. The results obtained allow ratify the possible use of the degree days as similar from the accumulated evapotranspiration, for the prediction of agricultural performance, as well as cover the first stage of quantitative character at a general level, whereas the sugarcane as individual species and prepare conditions for the arrival to a more qualitative stage in the yields prediction at of commercial level of varieties in this crop.