Studies in the mangrove plantations and adjacent areas revealed little chance for the natural
development of a second rotation crop in the existing plantations. In some islands of Noakhali
Coastal Afforestation Division, gewa (Excoecaria agallocha) showed promising performance
towards development of a second rotation crop. Of the available saplings and poles, E. agallocha
alone constituted 35 and 70 percent respectively. Studies on the scope of natural regeneration of
this species for sustainable development of mangrove plantations may be undertaken.

Acacia mangium seeds were subjected to six one-day pre-sowing treatments and their effects
on germination and seed deterioration in germination medium were studied under laboratory
conditions. The pretreatments were imparted by soaking the seeds, with and without funicle,
(a) in tap water (25^C) for three hours, (b) in boiled water (immediately after removing from heat
source) for one hour, (c) in boiling water for 30 seconds, and (d) treating with 95% sulphuric acid
for two minutes. Hot and boiling water treatments produced maximum germination, and at the
same time maximum damage to seeds. Other treatments had little effect on germination. A dry- •
weight analysis ofseed parts recorded 21% funicle, 30% seed coat, 47% cotyledon and 2% embryo
of the total weight.

Acacia auriculiformis and A.mangium the two fast growing exotic species have been introduced to Bangladesh for meeting the increasing demand offuelwood and poles. During last decade, thousands of hectares of plantation have been raised with these two species. In a number of A. auriculiformis plantations, several outstanding trees have been observed with good growth and vigour. These trees possess many characteristics of both good growth and vigour. These trees possess many characteristics of both A. auriculiformis and A. mangium. The hybrid trees coppice well and are somewhat resistant to heartrot disease in addition to its higher growth rate. The per unit area productivity of this hybrid would be higher than the existing output of either of the parent species. The use of vegetative propagulesrather than seedlings as a commercial forest regeneration method present an opportunity in genetic improvement.

The paper examines the suitability of utilization of rubber wood (Hevea brasiliensis) as an alternative to traditional wood. To this end its different properties have been determined and appropriate processing techniques have been developed. The results reveal that, inspite ofsome limitations, rubber wood may be used for a variety of purposes.

The growth and yield models/tables for Gmelina arborea Roxb. (gamar) in the plantations of Bangladesh have been prepared based on site indices. Models were derived by the data collected from permanent sample plots and also from temporary sample plots. Step-wise and all probable combinations of the independent variables methods were used to select the best suited models subject to the satisfaction of the statistical and biological requirements. Models were selected to estimate the stand dbh,stand mean height,stand basal area per hectare, total overbark volume yield per hectare and underbark volume yield per hectare upto top-end diameter of 10.0 cm. The yield prediction models derived in the study could satisfactorily be used for gamar plantations within the limitations ofstands of ages 3-12 years and site indices of 7.5 to 20.0 meters based on a base age of 12 years.

The effect of wax emulsion varying in concentration from 0 to 1.5% at 0.5% increments on the strength and dimensional stability of urea formaldehyde bonded particleboard at three glue levels, 8%, 10% and 12% has been observed. Results show that the addition of wax emulsion is useful to manufacture particleboard at low glue level, viz., 8% and 10%. But it does notshow any appreciable effect on the board made with 12% glue.

The properties of particleboards improve with increasing addition of wax emulsion for 8% glue and for 10% glue, the addition of 1% wax has beneficial effect on all the properties under investigation. Beyond this, further improvement is not marked. A combination of 10% glue and 1% wax is found advantageous to manufacture strong particleboard having good dimensional stability.

Seven plant species have been recorded as hosts of teak defoliator, Hyblaea puera Cram. (Hyblaeidae: Lepidoptera) in Bangladesh. Of them Avicennia officinalis Linn., a mangrove species, is a new host record of H. puera. The food preference ofthe pest larvae was evaluated for all the host plantspecies. Tectona grandis Linn, wasfound to be the most preferred food followed by Avicennia officinalis Linn., Callicarpa arborea Roxb., Vitex peduncularis Wall., V. pubescens Vahl., V. negundo Linn, and Oroxylunt indicum Vent.

The gross features and minute anatomy of jacaranda wood (Jacaranda acutifolia Humb. and
Bonpl.) have been described in details in this paper. The anatomical properties ofthis wood have
been correlated with the physico-chemical properties to determine the probable uses.

Leaf spot and twig blight diseases of Eucalyptus camaldulensis Dehnh. from 15- month-old plantationsfrom Khunia Palangbeat ofCox’s Bazar Forest Division, is reported. Symptoms ofthe diseases have been described. Colletotrichum gloeosporioides (Penz.) Sacc., a Deuteromycetes fungus was isolated and identified. It was the most frequent and found to be responsible for the diseases. The diseases were practically controlled and minimized by spraying the fungicide “Cupravit” at the rate of one gram per litre of water, twice at ten days interval.

Nine tree species growing in the villages of Bangladesh were studied to determine their suitability for making hardboard. Hardboards were made on defiberizing the pre-steamed chips mechanically. Strength and water-resistance properties of the boards were determined. It was found that none ofthe species could make hardboards good enough to meet the requirements of Class-1 hardboard of the US Hardboard Association Specifications. Nevertheless, all the species except neem, produced good, or even better, hardboards compared with sundri used in Khulna
Hardboard Mills.