A Half-yearly Peer Reviewed Journal of Bangladesh Forest Research Institute
During 1981-83, 12 to 16 years old jack fruit (Artocarpus heterophyllus L.) trees grown in Chittagong University campus were severely affected with brown leaf spots. Nigrospora sphaerica (Sacc.) Mason and Pestalotiopsis Versicolor (Sperg.) Steyaert were found to be associated with the disease (Herb. IMI No. 266275) and the pathogens are a new record for the plant. As these fungi have not been reported on jack fruit tree in Bangladesh, a study was made to determine their pathogenicity with jack fruit plant. The disease samples were collected and the symptoms of the disease were recorded carefully. The most characteristic symptoms of the disease appeared in the months of December, January and February. At first brown yellow coloured spots of 0.5-10mm. appeared on infected leaf and then the spots gradually coalesced and became larger to attain a size upto 11.0 cm.
The Two-way (Metric) Volume Table of telya garjan (Dipterocarpus turbinatus) for plantation forest published from the Bangladesh Forest Research Institute, Chittagong was reported to give higher estimate than the actual volume. A test of validity was, therefore, made for the table and also for some other existing volume functions of the species. It was found that the volume function of the table in metric units was incorrect and as such an appropriate function has been developed. An alternative volume function has also been proposed in the paper. Volume functions developed by other authors for this species have been found unbiased.
In this paper the general pith behaviour including the lacunae formation in the hollow culm internode and development of string like processes from nodal partition walls in Dendrocalamus giganteus Munro have been discussed. The young shoot in D. giganteus is solid, conical and covered with imbricating sheaths. It consists of solid massive tissue which ultimately develops into hollow internode with transverse partition wall without any outgrowth. The young shoot in solid state appears as dark coloured cross bars separated by light coloured parenchymatous tissue. The dark coloured zones become the nodal partition walls. The lacuna’develops through disintegration of coloured zones. The string like process that develops from the nodal partition wall is an abnormal behaviour of the pith. It consists of vascular bundles and parenchymatous tissue. The vascular bundles are of type III of Grosser and Liese (1971).
Variations of different provenances of mangium {Acacia tnangium Willd.) in survival and resistance to pests and diseases under Ilocos Norte, Masbate and Bukidnon conditions of the Philippines were studied. The survival at one and a half years and the resistance to pests and diseases at five years after planting were determined. The results show highly significant variations in per cent survival among provenances under Masbate and Bukidnon conditions and in resistance to pests and diseases under Ilocos Norte and Bukidnon conditions. The survival was the highest in the provenances 13622 (Sidci, Indonesia) in Masbate and 13232 (Cowley Beach Road, Qld) in Bukidnon. The best provenances resistant to pests and diseases were 13229 (Claudie River, Qld) in Ilocos Norte and 13236 (Kurrimine, Qld) in Bukidnon.
Morphological characteristics of the fruits and seeds, seed germination and seedling survival rate of seven albizias were studied in the nursery. The fruit size and weight were the highest in A. lebbek and the highest number of seeds per fruits was found in A. falcataria. The rate of untreated seed germination was tried in the seed tray, poly bag and seed bod. The highest germination was found in A. procera (76 – 85%) in all conditions and in A. falcataria (85%) only in the seed tray. The germination rate of A. lebbek was very poor in all the conditions. The germination period had no effect on the percentage of germination. The germinated seedlings in the seed tray and seed bed showed cent percent survival after 7 days transplanting into the poly bags in the shade and the survivality was 85 to 98% in the open sun after 30 days. No significant difference in survival was observed between the seedlings transplanted from the seed tray and seed bed.
Physical properties, such as, specific gravity, volumetric shrinkage and moisture content of Eucalyptus teriticornis have been studied from the pith to periphery and bottom to top position. Results show that specific gravity increases radially from the pith to outward, but decreases near the periphery. On the other hand, specific gravity increases significantly as the height increases. In the case of volumetric shrinkage, no such trend of variation has been observed. Moisture content decreases significantly from the bottom to top, whereas it docs not show any change from the pith to periphery.
Hardboards were made individually from the main stem wood, branches and twig as well as from the tree tops and thinnings of kcora, all without bark. Also hardboards were made from the above raw materials by adding 10% bark to each of them. Another set of hardboards were made using 50% main stemwood and 50% branches, tops and thinnings taken together with bark as it occurred in all the components. The boards were tested for determining strength and water resistance properties. It was found that only the unbarked main stem wood produced hardboards that would nearly be equal to class-I boards. The boards made from tops and thinnings did not give the properties of class-I boards, but they seemed to be good enough for making ‘standard hardboards.’ Hardboards made with the branches were very poor in quality. The presence of bark greatly reduced the properties in all the cases. Main stem wood, however, in mixture with 10% bark may not be unsuitable for making hardboards.
The paper deals on the drying characteristics for a simple solar heated wood seasoning kiln. Four hardwood species were dried in four mixed charges in the kiln throughout the year. The attainable temperature and relative humidity were determined both inside and outside the solar kiln. The drying rate and drying time were evaluated for the solar, air and steamheated methods. The solar kiln was found effective in drying timber throughout the year.
A tentative economic analysis of kraft and soda anthraquinone pulping of muli bamboo showed that better benefits can be achieved in soda + AQ pulping compared to its soda pulping. A mill producing 30,000 tons of pulp annually can save Tk 52.5 million by using soda + AQ process. Addition of AQ in low sulphidity kraft pulping is also profitable. Kraft]5 + AQ pulping of muli bamboo is capable of saving Tk 30 million compared to kraft]5 without AQ and Tk 7.6 million compared to normal kraft pulping. Addition of AQ in normal kraft pulping is not very encouraging where only Tk 5 million can be saved compared to normal kraft cook.
The analyses of the data collected on six occasions in between 1977 and 1990 from the permanent sample plots in the Sundarbans of Bangladesh arc presented in the present paper. The diameter at breast height (dbh) increment for the two important species — sundri (Jleritiera fomes Buch. Ham.), and gewa (Excoecaria agallocha Linn.) were estimated separately for all the site qualitics/hcight classes and salinity zones. The mean dbh increments per year ranged from 0.062 cm to 0.151 cm for sundri and 0.049 cm to 0.189 cm for gewa. There were only a small number of trees for passur (Xylocarpus mekongensis Pierre), keora (Sonneratia apetala Buch. -Ham), baen (Avicennia officinalis Linn.) and kankra (Bruguiera spp.). Therefore, the mean annual dbh increments were estimated for all the site qualities and salinity zones together. The mean dbh increments for passur, kcora, baen and kankra were 0.206 cm, 0.192 cm, 0.219 cm and 0.178 cm respectively. The increment rate was higher at higher site qualities and lower salinity zones. But it does not depend on the forest composition. Top dying sundri trees showed lower dbh increment rate.
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