Characterization of dhaincha accessions based on morphological descriptors and biomass production
Forty five accessions of dhaincha germplasms were collected from different parts of Bangladesh and characterized on the basis of morphological descriptors and biomass production ability. Thirty eight accessions were identified as Sesbania bispinosa, four as S. cannabina and two as unidentified Sesbania spp. One accession as S. rostrata was included for comparison. Both at seedling and maturity stages, wide and significant differences were observed among the accessions of different dhaincha germplasms for their biomass production capability and other morphological descriptors. At the seedling stage, total dry mass (TDM) production varied from 10.2 to 41.6g 30-plants–1. At the maturity stage, plant height, total number of branches and base diameter of dhaincha germplasms varied from 347.5–474.7cm, 10.4–23.7, and 1.9–4.9cm, respectively. The highest amount (4.10kg 10-plants–1) of above-ground TDM was produced in one accession of unidentified Sesbania sp. followed by S. rostrata and one accession of S. cannabina (3.85kg 10-plants–1), and the lowest TDM (0.9kg 10-plants–1) was measured in two accessions of S. bispinosa. It may be concluded that the biomass production capability of at least two accessions of local Sesbania germplasms were higher/comparable to that of exotic S. rostrata. It will be too early to make a conclusive remark based on only a few dhaincha germplasms. A detailed study with a large number of germplasms collected from whole Bangladesh is obviously needed to reach in a precise conclusion.
EFFECT OF HARVESTING AGE ON THE CHEMICAL AND MORPHOLOGICAL PROPERTIES OF DHAINCHA (SESBANIA ACULEATA) AND ITS PULPABILITY AND BLEACHABILITY
Dhaincha (Sesbania aculeata) is one of the annual plants in Bangladesh that has potential as a fiber source. It is a crop generally cultivated for its nutritive value to soil. This paper describes the effect of harvesting age of dhaincha on chemical, morphological, pulp, and papermaking properties and its bleachability. Dhaincha is a short length fiber that can be used as a substitute to hardwood. Fiber length was found to increase slightly with increasing age of the plant. The alpha-cellulose content in dhaincha increased and pentosan decreased with increasing age. Dhaincha pulp was prepared from 2, 3, 4, 5, and 6 month old plants under identical cooking conditions. Pulp yield (43-45 %) and kappa number (26-30) did not follow direct correlation with plant age. But physical properties of unbleached pulp increased linearly with the increase of age. Bleachability of dhaincha pulp was quite poor. The bleachability of pulp was improved when the age of dhaincha was increased.
Potential of mimosa (Albizia julibrissin) for papermaking
Mimosa Albiza julibrissin) is a fatt-growing perennial plant that can be grown on plantations at high yields. For mimosa to be a viable substitute for hardwood fibers in fine paper manufacturing papermakers need to know how mimosa responds to different pulping conditions and to different bleaching sequences. Experiments are being carried out at Auburn University Pulp and Paper Research and Education Center to deter mine the anatomic characteristics of fibers, the various aspects of cooking and the pulp qualities of mimosa, and the strength propetites of paper made from mimosa pulp. In terms of strength, pulp made from the mimosa is comparable to pulp obtained from typical southern hardwood (sweet gum). Pulp processing experimentts indicate the potential fro cost savings associated with the ease of pulping, bleaching, and refining of the mimosa fibers.