Harvest schedule for multi-purpose cane production

In the past few years, processing o f sugarcane progressed from sugar production to multipurpose production (sugar + energy + molecules o f interest). Co-products are better promoted resulting in a wide range of final products (ethanol, fuel, paper pulp, electricity, wax, bio-based compounds for example). The present study aims to evaluate the best harvest time in order to maximise the production for sugar, molasses, energy and organic acids. Sugarcane samples from three varieties were taken at five dates (every two months approximately), on plant crop and first ratoon. They were analysed for yield, sugar and nonsugar content and fibre characteristics. Results, expressed on a fresh weight basis, showed that yield, fibre and sugar increased until the final harvest; non-sugar content (in particular reducing sugars and organic acids) decreased. Therefore, sugar and energy production are highest when the yield is maximum. For molasses and organic acids production, the productivity was the highest earlier in the crop season. The present study shows that multi-purpose production can be optimised by timing of the harvest. (Résumé d'auteur