Adjustment of water-crop production models for ratoon sugarcane

ABSTRACT Production models need to be tested at different locations to be used as an agricultural planning tool. Hydric relations and performances of water-crop production models were used to estimate ratoon sugarcane yield along nine production cycles, in Paranavaí, Paraná State, Brazil. The crop reference and real evapotranspiration, soil water storage, water deficit and surplus were evaluated. The "Stewart" and "Jensen" models showed the best performance to estimate ratoon sugarcane yield. Water availability in the first development phase of ratoon sugarcane has the greatest influence on yield