The optimization of the harvesting is a key point in the energy chain since it affects the size pattern of the feedstock. For giant reed (Arundo donax L.), the harvesters for forage crops normally, used provide a product too much fine for meeting the requirements of biorefineries. Panacea group, in collaboration with Spapperi Ltd, has designed and developed a prototype for cutting and sectioning the Arundo plants aimed at producing a higher proportion of chips longer than the ones obtainable from a common harvester for forage crop. A study has been conducted in order to assess the performance of the machinery and to evaluate the characteristics of the product obtained.