• Journal of Forest and Environmental Science
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• v.34 no.2
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• pp.119-125
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• 2018

The tropical forests in developing countries are faced with the problem of illegal exploitation of trees. However, dearth of empirical means of expressing the dimensions, structure, quality and quantity of a removed tree has imped conviction of offenders. This study aimed at developing a model that can effectively estimate individual tree basal area (BA) from stump diameter (Ds) for Tectona grandis stands in Omo Forest Reserve, Nigeria, for timber valuation in case of illegal felling. Thirty-six $25m{\times}25m$ temporary sample plots (TSPs) were laid randomly in six age strata; 26, 23, 22, 16, 14, and 12 years specifically. BA, Ds and diameter at breast height were measured in all living T. grandis trees within the 36 TSPs. Least square method was used to convert the counted stumps into harvested stem cross-sectional areas. Six basal area models were fitted and evaluated. The BA-Ds relationship was best described by power model which gave least values of Root mean square error (0.0048), prediction error sum of squares (0.0325) and Akaike information criterion (-15391) with a high adjusted coefficient of determination (0.921). This study revealed that basal area estimation was realistic even when the only information available was stump diameter. The power model was validated using independent data obtained from additional plots and was found to be appropriate for estimating the basal area of Tectona grandis stands in Omo Forest Reserve, Nigeria.

• Journal of Forest and Environmental Science
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• v.26 no.1
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• pp.17-23
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• 2010

The present study was conducted to quantify wood and leaf litter decomposition and nutrient release of a dominant tree species, Tectona grandis Linn. F. in a tropical dry deciduous forest of Rajasthan, Western India. The mean relative decomposition rate was maximum in the wet summer and minimum during dry summer. Rainfall and its associated variables exhibited greater control over litter decomposition than temperature. The concentrations of N and P increased in decomposing litter with increasing retrieval days. Mass loss was negatively correlated with N and P concentrations. The monthly weight loss was significantly correlated (P < 0.05) with soil moisture and rainfall in both wood and leaf litter. Tectona grandis was found to be most suitable tree species for plantation programmes in dry tropical regions as it has high litter deposition and decomposition rates and thus it has advantages in degraded soil restoration and sustainable land management.

• Advances in Traditional Medicine
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• v.10 no.2
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• pp.59-65
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• 2010

In India, Tectona grandis is traditionally used in the treatment of diabetes mellitus and lipid disorder. In the present study, the antihyperglycemic and lipid lowering effect of ethanolic extract of bark of Tectona grandis (TG) was evaluated using alloxan induced diabetes in rats. Alloxan was given at the dose of 140 mg/kg, i.p. After induction of diabetes, TG was administered for 42 days p. o. and simultaneously different biochemical parameters like plasma glucose, liver glycogen content, serum triglyceride, cholesterol, LDL-cholesterol and HDL-cholesterol were estimated. Diabetic control showed significant increase (P < 0.01) in plasma glucose, serum triglyceride, cholesterol, LDL-cholesterol and significant decrease (P < 0.01) in serum HDL-cholesterol and liver glycogen content. Treatment with TG showed significant reduction (P < 0.01) in plasma glucose when compared with diabetic control. The elevated levels of serum triglyceride and cholesterol levels were significantly reduced (P < 0.01) by TG. TG treatment for 42 days showed significant decrease in serum LDL-cholesterol (P < 0.01) and significant increase in serum HDL-cholesterol level (P < 0.01). Moreover, diabetic control there was significant decrease in liver glycogen content which was significantly increased (P < 0.05) by treatment with TG. Hence, from the result obtained in the present study it can be concluded that Tectona grandis has the potential to treat diabetes condition and associated lipid disorder.

• Journal of Forest and Environmental Science
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• v.28 no.2
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• pp.63-67
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• 2012

Crown ratio is the ratio of live crown length to tree height. It is often used as an important predictor variable for tree growth equation. It indicates tree vigor and is a useful parameter in forest health assessment. The objective of the study was to develop crown ratio prediction models for Tectona grandis. Based on the data set from the temporary sample plots, several non linear equations including logistics, Chapman Richard and exponential functions were tested. These functions were evaluated in terms of coefficient of determination ($R^2$) and standard error of the estimate (SEE). The significance of the estimated parameters was also verified. Plot of residuals against estimated crown ratios were observed. Although the logistic model had the highest $R^2$ and the least SEE, Chapman-Richard and Exponential functions were observed to be more consistent in their predictive ability; and were therefore recommended for predicting crown ratio in the stand.

• Journal of Forest and Environmental Science
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• v.25 no.2
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• pp.119-126
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• 2009

An efficient in vitro plant regeneration system was developed through shoot proliferation from axillary buds of Tectona grandis (L.f), APNBV-1 (Andhra Pradesh North Badrachalam Venkatapuram-1) clone. Multiple shoots of high quality were produced in vitro from axillary bud explants. An average of 4.39 shoots/explant were obtained on Murashige and Skoog's (MS) medium supplemented with plant growth regulators (PGRs) benzyl amino purine (BA), kinetin (KN), indole acetic acid (IAA), gibberillic acid ($GA_3$), growth adjuvants casein hydrolysate (CH), adenine sulphate (Ads) and antioxidants ascorbic acid, polyvinyl pyrrollidine (PVP). Eighty five percent of rooting was observed in ex vitro rooting media containing IBA and vermiculite. In ex vitro rooting, single shoots with 2 to 3 nodes were subjected to IBA of different concentrations at different periods of time intervals. Direct rooting in vermiculite at 500 ppm concentration of IBA resulted in 4.3 number of roots with 2 cm length. Minimum response of rooting and length of roots were recorded at 100 ppm concentration of IBA. Planlets were transferred to plastic bags for short acclimatization stage in green house where they survived at 95%.

• Natural Product Sciences
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• v.3 no.1
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• pp.75-80
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• 1997

Preliminary antibacterial assay data that the Tectona grandis callus extract showed more antibacterial activity against E. coli and B. subtilis than the leaf extract led the authors to isolate the following antibacterial compounds from the callus. A mixture (3) of $2{\alpha},3{\beta}-dihydroxy-olean-12-en-28-oic$ acid (3a) and $2{\alpha},3{\beta}-dihydroxy-urs-12-en-28-oic$ acid (3b) exhibited the most potent antibacterial activity against both bacteria. The other 3 compounds, in the decreasing order of the activity, were identified as $2{\alpha},3{\beta}-dihydroxy-urs-12-en-28-oic$ acid (2), betulinic acid (1), and $2{\alpha},3{\alpha}$,23-trihydroxy-urs-12-en-28-oic acid (4). The antibacterial compounds (2, 3a, 3b and 4) were not detected or occurring in small quantities in the intact tissue, while they were observed in the callus. Only the less active compound 1 was present more abundantly in intact tissues than the callus.

• Journal of Forest and Environmental Science
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• v.34 no.4
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• pp.313-320
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• 2018

Tectona grandis (teak) is one of the most important timber species worldwide and India is one of the major teak growing countries. Though some volume equations were developed for teak in India but the models developed were neither evaluated using robust statistical criteria nor validated. Hence, the objective of this study was to develop statistically tested appropriate volume equation to predict total wood volume (over- and under-bark) for teak trees in Gujarat. A total of 41 trees with age varying from 15 to 33 years and diameter at breast height (dbh) from 7.3 to 30.8 cm were felled for the purpose. Linear and non-linear equations were used to model the relationship of the total wood volume with respect to dbh and total height. The equations tested mostly fitted well to the data. Model evaluation and validation indicated that models should be calibrated with local data for greater accuracy in the prediction.

• Journal of Plant Biotechnology
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• v.46 no.4
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• pp.291-296
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• 2019

This study was conducted to determine the effect of a light-emitting diode (LED) on in vitro shoot growth and rooting in teak (Tectona grandis L.). In the experiments with apical bud explants, the greatest shoot elongation (3.2 cm) occurred when they were cultured on DKW medium under 50% blue and 50% red LED mixture (BR), whereas no differences in growth were observed in different light sources (florescent light [F] or BR) or media (MS or DKW). The highest number of shoot multiplication (2.4/explant) or elongation (4.94 cm) was achieved with 0.5 or 1.0 mg/L 6-Benzyladenine (BA) treatment under BR. In addition, the best rooting rate (93.8%) or root length (1.3 cm) was recorded with 0.5 mg/L indole-3-butyric acid (IBA) treatment under BR, and the highest root induction (3.1/explant) was observed in 0.2 mg/L IBA under BR. The in vitro rooted plantlets were hardened and survived well on soil.

• Journal of Forest and Environmental Science
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• v.25 no.1
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• pp.1-24
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• 2009

Teak (Tectona grandis) is one of the most valuable timber yielding species in the world, with predominant distribution in tropical or sub-tropical countries. However, natural teak available only in few countries like India, Myanmar, Laos People's Democratic Republic and Thailand. Teak grows well in deep, well-drained alluvial soils, fairly moist, warm, tropical climate with pH ranges from 6.5-7.5. Teak is cultivated in many Asian, African and South American countries for timber production. The global teak plantations are estimated to be three million hectare with major share in India (44%) followed by Indonesia (33%). India is considered as richest genetic resources of teak with large areas of natural teak bearing forests (8.9 million ha), plantations (1.5 million ha), clonal seed orchards (1000 ha) and seed production areas (5000 ha). The studies on diversity of teak populations showed that teak is an out crossing species with major portion of diversity present within the populations. The productivity and quality of teak timber varies depending upon the site and environmental conditions. Teak wood is moderately heavy, strong and tough,straight grained, coarse textured and ring porous with specific gravity varies from 0.55 to 0.70. The sapwood is white to pale yellow in colour and clearly demarcated while heartwood is dark brown or dark golden yellow in colour. Teak is one of the most durable timbers in the world, practically, impervious to fungus and white ant attack and resistant to decay. Teak wood is used in ship and boat constructions, furnitures and aesthetic needs. Genetic improvement programmes have been undertaken in countries like Thailand, India, Malaysia and Indonesia. The programme includes provenance identification and testing, plus tree selection and clonal multiplication, establishment of seed orchards and controlled hybridization. Several aspects like phenology, reproductive biology, fruit characteristics, silvicultural practices for cultivation, pest and diseases problems, production of improved planting stock, harvesting and marketing, wood properties and future tree improvement strategy to enhance productivity have been discussed in this paper.

• Journal of Korean Society of Forest Science
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• v.96 no.5
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• pp.602-608
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• 2007

Forest plantations become important strategy not merely for the financial aspect, but for carbon sequestration and ecosystem stability. Forest plantations increase the density of the forest biomass, which reduce the increase in atmospheric carbon dioxide. Biomass density is also a useful variable for comparing structural and functional attributes of forest ecosystems across a wide range of environmental conditions. In this study, carbon sequestration of teak (Tectona grandis Linn. f.) in the individual tree and plantation levels estimation was carried out Site-specific allometric equation for the estimation of teak tree biomass was developed based on the direct measurement of fifteen (15) harvested trees in the Oak-twin Township of the Bago Yoma Region, Myanmar. A regression equation of the diameter at breast height (DBH) and the aboveground biomass (carbon content) was constructed to estimate the carbon storage level of plantations, which averaged 79 ton/ha. The average carbon accumulation in the soil (up to 30 cm in depth) was estimated 38.89 ton/ha, The highest mean annual increment (MAI) of total carbon was found in the 6-yr-old teak plantation (12.10 ton/ha/yr) whereas the lowest MAI was in the 26-yr-old teak plantation (4.31 ton/ha/yr).