FIBRE SORGHUM: INFLUENCE OF HARVESTING PERIOD AND BIOLOGICAL CYCLE ON YIELD AND DRY MATTER IN SOME HYBRIDS

摘要

The EU energy policy requires a gradual increase of the energy quota obtained from sustainable sources, in response to concerns about the difficulties of energy supply and environmental pollution. In this situation so careful to these environmental problems are opening up new prospects involving the use of biomass from wood and cellulose residue or from crops grown expressly cultivated. In the development of agricultural biomass for energy use some interest has been reserved for the fibre sorghum, annual and photosynthetic efficiency plant (C4), with low inputs farming techniques and resistant to water stress. Field experiments were carried out in a five year period (2001-2005) at the Inviolatella Farm of the CRA-QCE at Rome. This paper compares three genotypes of fibre sorghum characterized by different maturity classes: H128 (early maturing), 11133 (early-medium maturing) and H132 (late-maturing), in order to establish the optimal harvesting period in the environmental condition of Central Italy and maximize the yield of dry matter (biomass) avoiding an excessive moisture content and risks of stem lodging. Were investigated the effect of lour different harvest dates (0,7,14 and 21 days after flowering). The results of statistical analysis showed that the late-maturing hybrid H132 was more productive (28.9 t ha(-1)) but harvested of autumnal season, runs the risk of an unsuitable field drying. Early and early-medium maturing hybrid (H128 and H133) harvesting 7 or 14 days after flowering were the best compromise between yield and a safer and shorter drying in the field in climatic conditions of the Mediterranean summer.