OPTIMIZATION OF SUGARCANE HARVEST USING REMOTE SENSING
In Iranian sugarcane agro-industries, the harvest time is estimated by sucrose content. Measuring the sucrose content in the juice (pol) during sugarcane harvest season will help users and farmers to achieve the best time for sugarcane harvest, which is important in accurate agricultural management. In harvest season, the pol percent is measured weekly by the destructive method through sampling of different areas of representative farms. In the this method, all fields are not sampled due to the plurality of fields and the need for expenditure and workforce, and the measured samples do not represent the entire area of a field. The aim of this paper is to find an optimal model for determine best harvest time for four sugarcane varieties using satellite vegetation indices, and also to obtain a zoning map which represents the areas ready for harvest during a harvest season in order to achieve maximum sucrose content. The results showed that, compared with NDVI and GVI, GNDVI represented higher correlation with pol (R2=0.885). The optimum values of GNDVI were found to be between 0.5 and 0.55, which indicated the areas with highest sucrose concentration. In addition, the zoning map was presented that makes it possible to separate spatially the areas ready for harvest in each field and they were also showed that central areas of farms ripened (reach maximum sugar content) sooner than sideways.