Fibre dimension studies of five Bangladeshi woods, namely,
Moluccana koroi (Albizia falcataria), kainjal ( Bischof ia javanica},
jialbhadi (Lannea coromandelica’), narikeli (Pterygota alata) and chundul
(Tetrameles nudiflora) wets carried out to find out their suitability
in paper making. From the data, Runkel ratio, flexibility co-efficient
and relative fibre length, which influence certain pulping properties,
were deduced. Attempts were made to correlate fibre dimensions to
pulping properties of certain species namely, Moluccana koroi and
Kainjal. Considering the fibre length and certain anatomical
characteristics, the potentiality of narikeli for pulping has been
suggested. It is concluded that fibre dimensions along with pulping
properties and the manufacturing processes should be the guiding
principles in evaluating the suitability of the species in paper making.
1. Presented

Pestalotia sp., a fungal pathogen causing leaf blight disease of
pony al ( Calophylum enophylum Linn.), was isolated. The finding
was confirmed by the artificial inoculation of healthy leaves ofpanyai
plants with the isolated pathogen. Besides, the average quantitative
incidence and infection index of the disease on naturally infected
plants during 1976-1978 were estimated.

Of the 10 M m2 of raw hides produced annually in Bangladesh
only a fifth is tanned by 175 odd tanneries, using imported tanning
materials. Vegetable tannins can be extracted from roughly 10,000
tors of mangrove barks available annually at the felling coupes in
the Sundarbans. Amelioration of the properties of these tannins is,
however, a precondition to their use as tanning materials.
Tannins were extracted by various methods from goran {Ceriops
decandr a), kankra (Brugiera gymnorrhiza) and passur {Xylocarpus
molluccensis) barks collected from the Sundarbans. The percentages
of tannins obtained were 24, 21 and 17 respectively. A method was
developed for overall purification and improvement of colour and
quality of tannin. Chemical analysis indicates that the tannin is of
catechol group and quantitative analysis of the extractives shows that
the production of mangrove tannins would be an economically viable
proposition. Tanning experiments with goat skin show that light coloured
and fine-grained uppers and soles can be made with the purified tannins.
fpfCTr b bi’srsm xrsi
afis am bo
3^ts5fT<

The main economic aspects of the family Ve benaceae in relation
to the major categories of uses such as timber, medicine, food,
fodder, ornamental, insecticide, dye and live fences in Bangladesh
have been reviewed. Other passible uses have also been noted.
The medicinal uses are grouped disease wise. A checklist of Bangladesh
species with the indication of their economic uses has been appended.

Present seed use (11 kg for a nursery bed of 1.2 m x 12 m)
for kcora {Sonneratia apetala Buch.-Ham.) was found to be at least
55 times higher than the actual requirement for producing usable seedlings
in the Chittagong coastal area. No significant difference was
observed in respect of availablility of seedlings when pregerminated
and ungerminated seeds were sown. Seeds sown by broadcasting
showed significantly better performance than dibbling.

Top shoot borer damage causing high mortality to cane in the
cane arboretum of Bangladesh Forest Research Institute is reported.
The causal pest was identified as Ommatolapus hacmorrhoidalis
(Wiedemann ) (Curculionidae : Coleoptera). The nature and extent of
damage by the pest and susceptibility of different species of cane,
viz., jai or jali bet {Calamus guruba), karak or kirink or- baro bet
( C. viminalis var. fasciculatus), bhudum bet ( C. latifolius) and golak or
golla bet {Daemonorops jenkinsianus) to the pest were studied. Jali
bat was found to be highly susceptible to the attack of the pest
showing 62.7±4.62% shoot infestation whereas the other species were
resistant to the attack of this pest.

Ground-layering and air-layering trials were carried out on
bariala (Bambusa vulgaris) and muli bansh (Melocanna baccifera)
All the treated branches of B. vulgaris
produced successful propagules in the air-layering experiment. The
ground-layer in a of twelve culms (2 years old) of the same species
also produced 23 rooted and rhizomed propagules. Initiation
rooting and rhizome appeared only in
in both of the layering experiments,
to any of the layering methods.

In a preliminary study od pollen fertility percentages and
open pollination in emasculated flowers, leading to fruit formation in
Santalum album ( sandal) were investigated. Open-pollination percentage
measured through fruit formation was low. Inter-plant differences
both in pollen-fertility and in fruit formation were highly significant.
It was observed that though the pollen-fertility percentage is high,
fruit formation is low.

Only a fair price of jute for the
growers can ensure its sustained supply for
the industries or for export. Multifarious
uses and vigorous export promotion drives,
in their turn, can keep the demand of
jute to the desired level. Thus, a project
was undertaken for making paper-pulp
from jute using a process to give a higher
yield compared to the conventional kraft
process, yet retaining the kraft like properties.
The success of such a project is
likely to open the possibility of a perpetual
high demand of jute in the industrial sector.

Conventional soda pulping results in lower pulp yield and
strength properties. It also needs a much longer cooking time. To
overcome these difficulties a study on the effect of anthraquinone
( AQ ) in the alkaline pulping of Acacia auriculiformis was conducted.
The result showed that 3.1 percent point yield gain was achieved in
the soda pulping with 0.05% AQ addition. The yield was comparable
to that of the kraft control. Further increase of AQ did not substantially
increase the yield. In kraft-AQ pulping the gain in yield
was less remarkable, although 1.4 percent point gain was obtained.
Addition of AQ can substantially reduce the alkali requirement ?.nd/
or duration of cooking. The quality of the AQ catalysed pulp was
in no way inferior to the kraft control.
The feasibility of using AQ in a soda pulp mill in Bangladesh
has been shown. It indicates a remarkable economical gain.