Seasonal effect on the chemical composition of the leaves of Stipa tenacissima L. and implications for pulp properties

Abstract: Esparto (Stipa tenacissima) is a highly fibrous herbaceous plant. In addition, the fiber properties (suppleness, thinness, and cellulose content) make this plant a valuable raw material for papermaking in terms of both quality and quantity. In Tunisia, esparto is the only source of raw material for papermaking. In this paper, the chemical characteristics (cellulose, hemicelluloses, lignin, extractives, and ashes) of esparto leaves are analyzed in relation to growing conditions and plant biology. Four localized sites in the Kasserine region (central Tunisia) are examined. The chemical properties of esparto fibers vary significantly with site and season. In fall, esparto leaves contain more cellulose (46.4%) than in other seasons. In winter, esparto leaves have lower cellulose content (43.3%) and higher extractive content. The pulp properties across seasons indicate that pulp yield and strength properties are superior when leaves are harvested in fall. [Copyright &y& Elsevier]