A study on phonological characters of Silk Cotton tree revealed that the species commenced to shed leaves in December and became almost leafless in January, when it flowered. Fruits ripened in MarchApril and after shedding of fruits, new leaves and shoots appeared. Out of total dry matter of fruits, 21.1% was cotton-fibre (floss) and 12.6% was seed by weight. The average yield of cotton-fibre was 5.67 kg per tree per annum and the reproductive capacity ofthe species was found to be 33251.

A series of charges oftwenty timber species were dried employing solar drying as well as the conventional air drying and steam heated kiln drying methods. Solar and air drying were continued for three years during the entire drying seasons. The results suggest that the climatic conditions of Bangladesh are suitable for operating greenhouse type solar kilns throughout the year. Even refractory timbers of higher dimensions can be dried during the rainy season to a desired lower moisture content. The quality of the solar dried timber is found to be superior to both air and kiln dried timber. Solar drying is significantly more efficient than air drying. It is a simpler and less expensive drying technique than kiln drying. It is recommended that the solar drying technique be employed in wood based industries for effectve utilization of Bangladeshi timber.

No definite cutting age is maintained for extraction of bamboo for pulp and paper industries in Bangladesh. In this study an attempt has been made to find out the optimum cutting cycle for muli bamboo (Melocanna baccifera) from the point of view of pulp yield and quality. The results show that bleachable grade of pulp is obtained at a lower cooking time with younger bamboos (9 months old) than those of higher age groups. The pulp yield at a given point of delignification is the highest w’th 21 months old bamboos- Physical strengh properties of the pulp are independent of age. Thus, it seems that 21 months old muli bamboo is better for pulping.

Butterflies of the families Satyridac and Acracidac, collected from different forest areas of Bangladesh, have been identified. In Satyridac, there are ten species belonging to six genera. These include : Mycalesis mystes, M.
persons, M. sp., Elymnias hypermnestra, Melanitis leda, Orsotrioena medus, Erebia nirniala, E. narasingha, Ypthima chcnui and Y. philomela. In Acracidac, there is only one species, viz. Acraca violae. A taxonomic key has been developed for distinguishing the families, genera and species. The locality of collection of each species in different forest areas and its importance to forestry in Bangladesh have been noted.

The paper critically discusses the methods so far developed for determining the best rotations (years from planting to final cutting) for forest plantations in order to help professional forestry personnel to determine the appropriate growing periods for Bangladeshi forest stands. It is observed that most rotation models which are in use place a lot of emphasis on the needs of wood producers. The needs of the industries and other users generally receive less attention, Recent developments abroad have attempted to rectify this situation. It should be borne in mind, however, that no single method can be considered to meet all our needs even for public investment purposes. We are suggesting means to select the models consistent with maximum economic growth resulting from income and employment effects on the nation as a whole. The analysis also presents techniques to decide the time of the final cutting decision at the end of the predicted rotation in view of specific changes in the economic climate and other conditions.

Seven bamboo clumps, locally known as Baijjya bansh (Batnbtisa vulgaris Schrad.) flowered in the village Faridarpara near Bardarhat area of Chittagong town. Flowering started during February, 1979 in all these clumps. Out of the seven clumps, five flowered completely and died within 18 months. The remaining two clumps were found to be part-flowering in nature and were still in healthy and green condition, even after three years of flowering. Flowering which started during February, in both the part and the complete-flowering clumps continued till August-September with a pause from October to January. Flushes during flowering period were not purely continuous but it alternated with short interflushing gaps of 5 to 12 days.

Teak (Tectona grandis) pressure treated with an oil-borne preservative was investigated to find its usefulness as transmission poles. The pole size round Teak was found to contain an average of 45 percent sapwood which is readily perishable by wood destroying organisms. Teak poles were treated by the Bethel full-cell process using varying pressure and duration to evaluate their effect on the penetration and retention ofthe preservative mixture of 40 : 60 creosotelight diesel oil. With the increase of both treating pressure and time the increase in penetration was not found to be statistically significant. The retention, however, significantly increased with the increase of pressure but the increase of time could not produce any significant effect.

A penetration of 1.57 cm with retention of 174.64 kg/m³ of treated sapwood could be obtained by using 8.81 kg/cm² pressure for 3 hours. This penetration is considered adequate to protect the sapwood region of the pole.

An experiment was designed to observe the effect of tending treatments on the growth and development of Teak (Tectona grandis L.) saplings in Andermanik forest, Chittagong, in 1978. It was noticed that great variations existed among the plants after five months of planting. Close examinations suggested that the variability was related to the size of Teak stumps planted. This variability had a marked effect on survival and early development of the plants.