Sugarcane Productivity Simulation in Southeast of Brazil Using the DSSAT MODEL.

The irrigated Brazilian area for sugarcane  is small and located in semi-arid regions.  However, there is a great interest in evaluating the adoption of irrigated sugarcane in the country’s  southeastern region, where the rainfall depth  is satisfactory for the sugarcane production, since commercial pilot projects have shown promising results about  the increase productivity and  also sugarcane fields increase longevity. The aim of this study was to simulate the stem’s   potential productivity and the extraction of sugar from sugarcane cultivated in two sub-humid regions of Brazil, analyzing four varieties in different planting dates, under two situations: rainfed and irrigated. The simulation model was the CANEGRO / DSSAT (Decision Support System for Agrotechnology Transfer) and the four varieties of sugarcane evaluated were RB86 7515, CTC 4,  CTC 7 and CTC 20 (all in a cycle of 1.5 years). In rainfed conditions, the results showed that sugarcane planting is best in September and November for region 1. In region 2, the planting was not indicated for rainfed conditions due to water deficit throughout the year. In irrigated environment, there was no difference in the stem productivity according to the planting date for all varieties,  in both  regions evaluated. The productivities of stem and sugar were always higher in irrigated environment when compared to the rainfed, in all locations and varieties. The simulation model generated optimum estimative of stem and sugar yields compared to experimental data obtained in the region.