ABSTRACT
Experiments carried out in the coastal areas of Bangladesh indicated that, from physiological stand point, the optimal time for planting of keora (sonneratia apetala) seedlings lies between June and August. Seedling survival was found to be related to climatic factors. Seedlings of age between 6-8 months showed the highest survival after planting.

ABSTRACT’ Keora (Sonneratia apetala Buch.-Ham.) is the principal plantation species in the coastal areas of Bangladesh. A yield prediction model was developed for keora plantations by regression techniques using the dominant height attained at a reference age of 12 years. The model composed of four equations : stand dominant height equation, stand mean diameter equation, stand basal area equation and stand volume yield equation. The proposed model was verified using a separate set of data from 30 sample plots. This model was found to be suitable for estimating growth and yield of keora in the coastal plantations of Bangladesh.

The effect of anthraquinone (AQ) addition in kraft and soda pulping of bagasse has been studied in the laboratory. The results show that AQ addition by 0.05% in soda pulping increases the pulp yield by 2.5 per cent units compared to normal soda pulping. The yield increases by 4.5 per cent units by using 0.15% AQ. In kraft -AQ pulping, the gain in yield is less remarkable. The quality of the pulp improves by addition of AQ both in soda and kraft pulping.

The efficacy of five systemic insecticides, namely, diazinon, dicrotophos, dimethoate, phosphamidon and oxydemeton-methyl, each at 0.1% a. i., was studied against the top shoot borer, Ommatolapus haemorrhoidalis (Wiedemann) (Curculionidae : Coleoptera) of cane (Calamus tenuis Roxb.). The insecticides were applied as foliar spray on 3-years old cane plantation at the Cane Arboretum of Bangladesh Forest Research Institute, Chittagong. Each insecticide reduced pest population significantly against the unsprayed control. Phosphamidon and oxydemeton-methyl worked better in reducing the pest attack followed by diazinon, dicrotophos and dimethoate. No visible phytotoxicity was recorded for any insecticide tested.

The physical and mechanical properties of one year to five years old muli and borak bamboos have been studied. The moisture content and the shrinkage change significantly along the culm height. The age has substantial effect on these properties for borak, but not for muli. Specific gravity differs considerably with height and age. Mechanical properties have also changed with age and height position. Both the species have been found to attain maturity in respect of specific gravity and bending strength at the age of three years.

The anatomy of two bamboo species, Arundinaria falconeri and Sinobambusa tootsik was investigated to know the effect of anatomical features on the pattern of preservative penetration inside the culm cells of these species. The study indicates that in bamboos the most advantageous pathway for the longitudinal flow of preservative liquid is through the vessels. The parenchyma aids in only to lateral flow. Vascular bundles of both the species fall under type-1 of the four types categorised by Grosser and Liese.

Eucalyptus camaldulensis is one of the major fast growing exotics in Bangladesh. The paper attempts to determine the optimum cutting time and the profitability of plantation of the species for fuelwood in Bangladesh. Optimum rotation has been determined in terms of volume production, turnover, forest rent, financial maturity (marginal), land expectation value (LEV) and internal rate of return (IRR). Sensitivity analysis has also been carried out to observe the effect of changes in different cost elements, reduction in yield and revenue on rotation. All decision criteria indicate an optimum rotation length in between 6 and 8 years in case of firewood plantation on average sites at 1.83 m x 1. 83 m (6′ x 6′) spacing.

Rubber (Hevea brasiliensis Mull.-Arg) is an economic tree crop in Bangladesh. It was first introduced in Bangladesh by the Forest Department in 1952. About 287 ha of land were planted under a pilot scheme by 1959. In 1962, the Rubber Plantation Project was handed over to Bangladesh Forest Industries Development Corporation (BFIDC). By 1985, BFIDC planted 7,383 ha of land in 11 different Estates of the country. Die-back has now become a problem in these plantations. In recent years, BFIDC reported that there had been a severe infection of die-back disease in the Rupaichhara Rubber Estate of greater Sylhet district.

Jack fruit (Artocarpus heterophyllus Lamk.) is an important fruit tree of Bangladesh. Fruit rot, pink disease, brown leaf spot, root disease, die-back and canker are common fungal diseases of jack fruits in Bangladesh (Parham 1942; Vaahall 1925; Batista and Vital 1954; Park 1937; Rahman et al. 1987).

Paederia Linn. (Rubiaceae), a genus of climbing shrub, is distributed in the tropics and represented by about 50 species (Airy-Shaw 1973). Hooker (1881), Prain (1903) and Heinig (1925) reported only P. foetida Linn, from Bangladesh. During a recent collection trip a specimen of Paederia was collected from Ruma, Banderban. While examining the specimens of Paederia, this member of Paederia did not match with P. foetida. The specimen was identified as P. lanuginosa Wall, and compared with the original protologue of Wallich (1831). The specimens at Bangladesh National Herbarium, Dhaka (DACB), were also examined. This species was earlier reported to occur in Burma (Wallich 1831, Kurz 1877 and Hooker 1881). But there is no report of the occurrence of this species from Bangladesh in any of the floristic works consulted, viz. Hooker (1881), Prain <1903), Brandis (1906). Heinig (1925), Raizada (1941), and Khan and Banu ■1972).