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    I C Madakadze, T M Masamvu, T Radiotis, J Li, D L Smith
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    ABSTRACT: Shortage of conventional raw material for the pulp and paper products together with the increasing world demand for paper has renewed interest in non-wood fibres. Non-wood pulping capacity has been increasing steadily over the last decade. A lot of crops grown for biomass, like switchgrass (Panicum virgatum L.), are good examples of plants with potential for pulp production. Raw material chemical composition, kraft pulp yield and properties, and fibre characteristics of elephant grass or hybrid pennisetum (Pennisetum purpureum Schum. cv. SDPN3) and switchgrass (cv. Cave-in-Rock) were determined in an effort to evaluate them as raw materials for pulp and paper production. Elephant grass had -cellulose and Klasson lignin contents of 45.6 and 17.7%, respectively. The respective values for switchgrass were 41.2 and 23.89 %. Pulp yields, following a mild kraft process, were 48 and 50% for switchgrass and elephant grass, respectively. The corresponding kappa numbers were 15.5 and 9.2. The weight-weighted fibre length averaged 1.32 mm. Pulp freeness was higher for switchgrass (330 mL) than for elephant grass (139 mL). Elephant grass had a burst index above 5.85 kP.m 2 g -1 . These characteristics demonstrate the suitability of both elephant grass and switchgrass for pulp production.
    African Journal of Environmental Science and Technology. 08/2010; 4:465-470.
  • Crop Science 01/2003; 43(3). · 1.51 Impact Factor
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    ABSTRACT: Chlorophyll meters have been used to estimate leaf chlorophyll content, and therefore nitrogen (N) status and fertilization requirements for several crops. However, until now C4 forage grasses have not been investigated in this regard. A field study was conducted in 1995 and 1996 to evaluate the potential of chlorophyll (SPAD) meter readings to determine switchgrass N concentration and herbage yield. Meter readings were taken on the top most fully expanded leaves of switchgrass grown on a free draining sandy clay loam soil (St Bernard, Typic Hapludalf) fertilized at 0, 75, or 150 kg N ha. The switchgrass was either cut at the end of the season or every four or six weeks. Herbage N concentration in uncut stands declined with time while SPAD readings increased to a mid‐season maximum, beyond which they declined rapidly. The relationship between N concentration and SPAD readings was linear (r=0.62–0.93; p
    Journal of Plant Nutrition - J PLANT NUTR. 01/1999; 22(6):1001-1010.
  • Crop Science - CROP SCI. 01/1999; 39(2).
  • I.C. Madakadze, T. Radiotis, J. Li, K. Goel, D.L. Smith
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    ABSTRACT: Non-wood fibres are increasingly being used in the pulp and paper industry to help meet the increasing world demand for paper. Their use also helps to reduce demand on declining forest reserves. In this study several warm season grasses, prairie sandreed (Calmovilfa longifolia (Hook.) Scribn.), cordgrass (Spartina pectinata L.), big bluestem (Andropogon gerardii Vitman), and switchgrass (Panicum virgatum L. cv. Pathfinder (PF) and New Jersey 50 (NJ50)), were evaluated as potential raw materials for pulp and paper production. Raw material chemical composition, kraft pulp yield and properties, and fibre characteristics were evaluated. All these grasses were easily pulped under a mild kraft process, with pulp yields ranging from 44 to 51%, highest yields were recorded for NJ50 and big bluestem; and kappa numbers ranging from 10 to 16. The weight-weighted fibre length ranged from 1.29 to 1.43 mm, the highest value being recorded for big bluestem. The unbeaten pulp freeness ranged from 275 ml for sandreed to 411 ml for NJ50. Sandreed, NJ50 and big bluestem had high tear indices of 7.49, 7.12 and 7.07 mN m2 g−1, respectively. Cordgrass and sandreed had burst indices above 5.0 kPa m2 g−1 (5.68 and 5.22 kPa m2 g−1, respectively). Other physical and strength properties are also presented.
    Bioresource Technology 01/1999; · 5.04 Impact Factor
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    ABSTRACT: Switchgrass (Panicum virgatum L.) is one of several warm-season grasses that have been identified as potential biomass crops in North America. A two-year field study was conducted, on a free-draining sandy clay loam (St. Bernard, Typic Hapludalf), to characterize the growth and evaluate changes in biomass accumulation and composition of switchgrass at Montreal, QC. Three cultivars, Cave-in-Rock, Pathfinder, and Sunburst, were grown in solid stands in a randomized complete block design. Canopy height, dry matter (DM) accumulation and chemical composition were monitored biweekly throughout the growing season. Average maximum canopy heights were 192.5 cm for Cave-in-Rock, 169.9 for Pathfinder, and 177.8 for Sunburst. The respective end-of-season DM yields were 12.2, 11.5, and 10.6 Mg/ha. Biomass production among cultivars appeared to be related to time of maturation. Nitrogen concentration of DM decreased curvilinearly from 25 g/kg at the beginning of the season to 5 g/kg DM at season's end. Both acid-detergent fiber (ADF) and neutral-detergent fiber (NDF) concentrations increased to a maximum early in the season, after which no changes were detected. The average maximum values of ADF and NDF were, respectively, 647.6 and 849.0 g/kg DM for Cave-in-Rock, 669.1 and 865.2 for Pathfinder, and 661.8 and 860.9 for Sunburst. Changes in canopy height, DM accumulation, and chemical composition could all be described by predictive regression equations. These results indicate that switchgrass has potential as a biomass crop in a short-season environment.
    Agronomy Journal - AGRON J. 01/1999; 91(4):696-701.
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    ABSTRACT: Field studies were conducted in 1994 and 1995 to determine the phenology, leaf and tiller characteristics and yield of 22 warm-season grasses in south western Quebec, Canada. Cordgrass (Spartina pectinata L.), two cultivars of Indiangrass [Sorghastrum nutans L. (Nash)], two cultivars of big bluestem (Andropogon gerardii Vitman), 12 cultivars of switchgrass (Panicum virgatum L.) and five cultivars of prairie sandreed [Calamovilfa longifolia (Hook) Scribn., were included in the study. In terms of initial spring growth, CWNC (cordgrass) and New Jersey 50 (switchgrass) were the earliest and latest, respectively. Initial spring regrowth from sandreeds was predominantly from continued growth of biennial tillers, from rhizomes in cordgrass and from buds on stem bases for the other species. The earliest maturing entries were ND3743, Dakota, Ottawa3 (switchgrasses) and Bison (big bluestem). New Jersey 50 and CWNC were the latest maturing. CWNC had high tiller numbers throughout the season while the rest of the entries showed increases in tiller numbers in summer. There were significant differences among entries in height development across the season. Biomass yields ranged from 65 to 861 g per plant. Lignocellulose concentration was high in all entries with neutral detergent fiber (NDF) and acid detergent fiber (ADF) ranging from 770–860 g kg−1 and 460–540 g kg−1, respectively. Nitrogen and ash concentrations ranged from 4–10 and 40–70 g kg−1, respectively. The results indicate potential for cordgrass (CWNC) and several switchgrasses for biomass production in the short season areas of Quebec.
    Bioresource Technology 01/1998; · 5.04 Impact Factor
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    ABSTRACT: Switchgrass (Panicum virgatum L.) has been identified as a potential biomass crop in North America. A two-year study was conducted to characterize leaf area development and estimate radiation-use efficiency (RUE) of switchgrass in eastern Canada. Three cultivars, Cave-in-Rock (CIR), Pathfinder (PF) and Sunburst (SB) were grown in solid stands in a randomized complete block design. Dry matter (DM) yield, leaf area development and light interception were monitored bi-weekly throughout the growing season. Herbage subsamples were hand separated into leaf and sheath-stem fractions. Mean seasonal maximum leaf area indices (LAI) were 6.1, 5.3 and 5.1 for CIR, PF and SB, respectively. By early July of each season the canopies were intercepting about 90% of the incoming light. End of season DM yields were 12.2, 11.5 and 10.6Mg ha−1 for CIR, PF and SB, respectively. The stem plus leaf sheaths constituted the major component of DM and its accumulation trend parallelled that of total DM. End of season stem-sheath components averaged 764, 714 and 691 of the total g kg−1 DM for CIR, PF and SB, respectively. Energy contents of the switchgrasses averaged 17.4 MJ g−1 DM and did not vary among cultivars or during the season. This translated into total energy yields ha−1 of 216 GJ for CIR, 197 for PF and 186 for SB. Radiation-use efficiencies computed using total incoming solar radiation, for the near linear growth phases, averaged 1.07g DM MJ−1 for CIR, 0.90 for PF and 0.89 for SB. The respective values based on photosynthetically active radiation were 2.20, 2.00 and 1.96g DM MJ−1. Changes in LAI, relationships between LAI and light interception and DM yield could all be described by predictive regression equations. These results indicate the potential of switchgrass as a biomass crop in short season areas.
    Biomass and Bioenergy 01/1998; 15(6):475-482. · 2.98 Impact Factor
  • Crop Science - CROP SCI. 01/1998; 38(3).

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