Where does teak grow?

What’s so great about teak wood furniture?

Anyone who does a little research before buying new furniture — especially patio furniture — will almost definitely run across a few ads for teak wood. One of the first things that will jump out at potential buyers is that furniture made from teak wood is consistently among the most expensive. Why? The reason is that teak is valuable both for its elegance and its durability. Beyond its beauty, it also possesses some natural properties that other woods don’t have.

Teak has always been a prized material. The tree that teak comes from, Tectona grandis, is native to the tropics. Since around the 7th century, it has been used to outfit and adorn the residences of the wealthy and powerful . The wood’s reputation made its way out of the region through the Dutch, who colonized Indonesia. They used the wood for shipbuilding; teak makes for an excellent ship wood due to its ability to ward off dry rot (we’ll get to that in a minute).

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Teak is found in Southeast Asian nations like Thailand, Burma and Malaysia, but perhaps no central government takes its teak quite as seriously as Indonesia’s. Since the country’s post-colonial era began in the mid-20th century, the Indonesian government has had a corporation in place dedicated to managing one of the nation’s most valuable natural resources. The company, PT Perhutani, maintains the official teak plantations on the Indonesian island of Java. Here, a predetermined number of trees that can be felled each year. Each tree is replaced with a new one that’s planted on the plantation.

Since the best wood furniture made from teak comes from mature trees, it can take around 80 years before a teak tree planted today is harvested for wood. Because of this, and because teak is such an excellent wood material, old teak is often reclaimed — for example, from old structures slated to be torn down — and given new life as furniture.

Why is teak wood so prized and so valuable? Find out on the next page.

Teak

Color/Appearance: Heartwood tends to be a golden or medium brown, with color darkening with age.

Grain/Texture: Grain is straight, though it can occasionally be wavy or interlocked. Coarse, uneven texture and moderate to low natural luster. Raw, unfinished wood surfaces have a slightly oily or greasy feel due to natural oils.

Endgrain: Ring-porous or semi-ring-porous; large to very large solitary earlywood pores, medium to large latewood pores, few; solitary and in radial multiples of 2-3; tyloses and other heartwood deposits (light-colored) common; medium rays visible without lens, spacing normal; parenchyma vasicentric, and banded (marginal), with bands sometimes wide enough to enclose entire earlywood pores.

Rot Resistance: Teak has been considered by many to be the gold standard for decay resistance, and its heartwood is rated as very durable. Teak is also resistant to termites, though it is only moderately resistant to marine borers and powder post beetles.

Workability: Easy to work in nearly all regards, with the only caveat being that Teak contains a high level of silica (up to 1.4%) which has a pronounced blunting effect on cutting edges. Despite its natural oils, Teak usually glues and finishes well, though in some instances it may be necessary to wipe the surface of the wood with a solvent prior to gluing/finishing to reduce the natural oils on the surface of the wood.

Odor: Teak can have a leather-like scent when freshly milled.

Allergies/Toxicity: Although severe reactions are quite uncommon, Teak has been reported as a sensitizer. Usually most common reactions simply include eye, skin, and respiratory irritation, as well as other health effects, such as pink eye, rash, nausea, asthma-like symptoms, and vision effects. See the articles Wood Allergies and Toxicity and Wood Dust Safety for more information.

Pricing/Availability: Despite its widespread cultivation on plantations worldwide, Teak is very expensive. It is perhaps one of the most expensive lumbers on the market, at least for large-sized, non-figured wood. Other woods are more expensive, but are typically only available in small pieces, (i.e., Gaboon Ebony or Snakewood), or they are valued solely for the figure of their grain (i.e., burl woods, Pommele Sapele, or Waterfall Bubinga).

Sustainability: This wood species is not listed in the CITES Appendices or on the IUCN Red List of Threatened Species.

Common Uses: Ship and boatbuilding, veneer, furniture, exterior construction, carving, turnings, and other small wood objects.

Comments: Sometimes called Burmese Teak, this name is used to differentiate natural-grown trees (typically from Myanmar, aka Burma) from Teak grown on plantations. Used extensively in India and within its natural range for centuries, Teak has grown into a worldwide favorite. With its superb stability, good strength properties, easy workability—and most of all, its outstanding resistance to decay and rot—it’s no wonder that Teak ranks among the most desired lumbers in the world.

Much like the many names and knockoffs of Mahogany, the moniker “Teak” has been affixed and assigned to a number of different woods seeking acclaim. The usual procedure is to take a wood bearing any degree of resemblance to Teak and insert a geographical location in front of the name. For instance, Cumaru is sometimes referred to as Brazilian Teak, while Rhodesian Teak bears little botanical relation to real Teak—Tectona grandis. The name Burmese Teak, however, does refer to genuine Teak.

Related Species:

None available.

  • Gluing Oily Tropical Hardwoods

Scans/Pictures: A special thanks to Steve Earis for providing the wood sample (curly veneer) and turned photo of this wood species.

Teak (sanded) Teak (sealed)
Teak (endgrain) Teak (endgrain 10x)
Teak (curly) Teak (turned)
Teak (27″ x 7.1″)

Teak

Site factors

Teak grows well in alluvial soils, fairly moist, warm, tropical climate with pH ranges from 6.5 to 7.5. Teak show ed poor growth and form on dry sandy soil, shallow or hard pan soil, acidic, laterite, black cotton and water logged soils. It is a light demanding species relatively high light intensity , i.e. between 75 and 100% of sunlight for better growth and development. It occurs from sea level to an altitude of about 1200 m with 800-2500 mm rainfall regime and also grows in very moist areas with the annual rainfall of over 3,500 mm. Teak also grows in dry areas of Tamil Nadu, Rajasthan, Madhya Pradesh, Andhra Pradesh and Maharashtra. In the Indian Peninsula, teak experiences maxim um temperatures up to 48oC and minimum about 2oC in the dry zone of Central India while in the moist parts of the Southern India (west coast), the maximum and minimum temperatures of teak distribution ranges fr om 43oC and 13oC respectively.

Planting stock

Generally stumps or seedlings are used as planting material. For stump preparation, the seedlings have to be maintained in the nursery for about one year. Then the seedlings are uprooted, all the leaves and and secondary roots are removed and stumps (4 to 6 cm shoot with 15 to 20 cm tap root portion) were prepared. Stump planting is generally preferred and it is easy for transport. For seedling plantation, young seedlings are shifted to 2 polythene bags containing soil mixture and maintained in the nursery for 3 to 6 months.

Seed collection, processing and Nursery techniques

Generally teak starts flowering 6 years after planting, but profuse flowering occurs after 15 years. Flowering occurs from June to September and fruits can be collected from November to January. Though teak produces profuse flowering the fruit set was very poor (1 to 2%), probably the coincidence south w est monsoon with flowering which affects pollination.

Germination of teak is often poor due to dormancy. Pre – treatment of the seeds by alternate wetting and drying of the seed for a w eek is required to break the dormancy before sowing . The seeds were kept in a gunny bag and dock the bag in water , preferably in a running stream, for 12 hours, then spread the seed in the sunlight to dry for 12 hours. This has to be repeated for one w eek. Further grading of fruits according to size help in improving germination. Germination increases with increase in size of fruits .The germination percentage varies from 30 to 50 % in moist teak and 5 to 10 % in dry teak. The seeds were sown in the raised nursery beds (10 x 1 x 0.3 m) prepared with soil and sand mixture. The nursery beds have to be watered regularly and covered with coconut leaf or paddy straw. Germination starts 10 to 15 days after sowing and continues up to 35 to 45 days . The paddy straw may be removed once the seed started germinating . The seedlings can be transplanted to polythene bags or it can be maintained in the nursery beds for 10 to 12 months for preparation of stumps.

Plantation management

A suitable land with good soil and rainfall of > 1200 mm ma y be selected for raising teak plantation. The land should be ploughed thoroughly and prepare pits ( 45 x 45 x 45 cm) in 2 x 2 m or 3 x 3 m or 3 x 4 m spacing before rainy season. Farm yard manure with soil mixture has to be prepared and filled in the pits. Seedlings are planted in the pits during rainy season. For stump planting crowbar may be used and pitting is not required. In the initial stage the plants have to be watered weekly, and regular weeding and pruning have to be done . The branches have to be removed periodically without affecting the main stem. Drip irrigation is beneficial in farm lands . Irrigation reduce the rotation period and also enhance the productivity . Application of 50 g of urea and 30 g of super phosphate after six months and 75 g of urea and 60 g of super phosphate after 24 months of planting increases the growth rates. The fertilizers are effective for enhancement of growth in young teak trees than mature trees. Thinning (removing alternate rows) is done 5 years and 10 years after planting in plantation raised with closer spacing (2 x 2m). Mechanical thinning is also needed. The interval of thinning cycle is at age of 5, 10, 15, 20 and 30 for 60 year rotation, in Kerala. Teak can also be planted in bunds in south and north direction in such way the agricultural crops get sufficient light. It was found that there w as no significant variation in wood properties of young (25 to 30 years old) and mature teak (50 to 60 years old). Therefore teak plantation raised with good quality planting material or clones in good soil with limited irrigation and dry period with silivicultural practices can be harvested within 20 to 25 years. In Brazil and Malaysia teak is harvested at the age of 15 to 20 years. The teak growing in the canal areas in Thanjavur and Tiruvarur (Tamil Nadu) showed fast growth with good girth (> 150 cm) within 20 years and canal teak is harvested at the age of 30 years.

Agroforestry practices

Teak is one of the favoured silvicultural species by the farmers. It is planted in different models, combinations as well as in different spacements. IFGTB has developed agroforestry models like, Agri-silvicultural models (Teak + casuarinas with agricultural crops maize, cotton, turmeric, tomato and chilly), Agri-silvi-horticulture model (Teak + coconut with agricultural crops plantain, turmeric , vegetables, maize and cotton) and Silvi-horticulture model (Teak-Gauva, Annona) (George, 2000). Under irrigated lands, silvipasture model was developed with Teak and Casuarina as tree component and Napier and Guinea as pasture components.

Yield

The average productivity of teak in Nilambur teak plantations was 2.85 m3 ha -1 year -1 in 53 years rotation period. In Indonesia the MAI at the harvest age (40 to 90 years) w as 2.91 m 3 ha -1 y ear -1 (FAO, 1986). The productivity in moist semi deciduous forest in Ghana was 8-10 m 3 ha – 1 y ear -1 (Oteng-Amoako and Sarfo, 2005) while in Central America it was 8 to 12 m 3 ha -1 year -1 (Arias , 2005). Recent studies conducted on teak growing in farmlands with irrigation, fertilizer application and management revealed the possibility of reducing the rotation period to 25 y ear s with increase in productivity. The trees grow in farm lands grow f aster and produce more biomass when compared to plantations in the forest areas. The quality of teak timber in farmland at 12 years was found to be similar to that of 20 years in forest land.

Important insect pest and diseases

Teak defoliator , Hyblaea puera and leaf skeletonizer , Eutectona machaeralis are considered to be the major pests in teak. These insects are known to occur on seedlings in nurseries and also in grown up trees in plantations . H. puera feeds on tender foliages during the early part of the growth season and E. machaeralis feeds on older foliage towards the end of the season. Making regular pest surveillance in nurseries and young plantations, particularly during rainy season when there is a new flush formation to detect the occurrence of the pest and removal and destruction of larvae if the population is less. If the pest attack is severe it can be controlled by spraying of the foliage with the chemicals like monocrotophos or endosulfan 0.05-0.075% or neem based formulations (Neemazal 1%) at 10-12 days intervals can give good control. A virus (NPV) based formulation (biocide) is also available for management of the defoliator H. puera.

Uses

It has been extensively used for decking , deck houses , rails , bulwarks , hatches , weather doors and planking . The traders and timber users recognized several varieties of teak suitable for different end uses. The huge teak trees from Western Ghats region (high rainfall range) are used for structural needs like ship and boat building , construction and bridge building . Teak from Central Indian region is known for colour, texture and grains preferred for furniture and aesthetic needs. Teak wood of Godavari valley in Andhra Pradesh is used for furniture and cabinet making for its ornamental figuring. Teak wood markets and depots are available in all teak growing states in India.

Source: Transfer of Tree Cultivation Technologies to Krishi Vigyan Kendras – Publication by Institute of Forest Genetics and Tree Breeding,Coimbatore.

10 Facts About Teak Wood

At AquaTeak, we use only the finest teak wood grown on Indonesian, government-managed plantations and milled by the leading producer of teak wood in the world. Our teak shower benches are second to none.
So why do we use teak?
Simply put, it’s amazing wood!
Here are 10 interesting facts about teak wood, just in case you were wondering…

  1. Teak is the common name for the tropical hardwood tree species, Tectona grandis, which grows to over 130 feet tall.
  2. Teak is native to south and southeast Asia, India, Indonesia, Malaysia, Thailand and Burma.
  3. Teak wood tends to be a golden or medium brown. Its color darkens over time.
  4. Teak is known for its incredible durability and water resistance.
  5. Teak has a high oil content, giving it the highest decay-resistance among all natural wood products.
  6. Teak is used for boat building, yachts, exterior construction, indoor and outdoor furniture, veneer, carvings, frames, and more.
  7. Teak doesn’t crack, wrap or turn black when in contact with metals.
  8. Teak is resistant to termites and other pests.
  9. Teak trees that are older, between 40 and 80 years old, provide the best wood.
  10. Teak — before it can be cut into lumber — must be dried for 1-2 years.

With teak, you can’t go wrong! It’s the ‘gold standard’ of wood. Which is why teak is all we use for our beautiful teak shower benches and stools. Shop AquaTeak online and check out our gorgeous line of teak furniture. See why we’re the largest manufacturer of teak shower benches in the world!

Where Does Teak Wood Come From?

Ask any patio furniture owner and he will tell you that teak is THE best material for making outdoor furniture. Aside from being downright beautiful, teak is strong and has natural properties that will keep mold, pests, and moisture away. Teak furniture is available almost anywhere and even if this is one of the most expensive, these furniture pieces are an investment.

Origins of teak wood

Teak is a prized wood material. Teak trees come from, Tectona grandis, and are native to tropical countries. Around the 7th century, it was used to adorn the residences of wealthy and powerful and powerful families and clans in Indonesia. Teak wood’s amazing reputation has made its way to the Dutch, who colonized Indonesia. They used teak wood for building ships because of its excellent ability to ward off rotting.

Teak trees are found in Southeast Asian nations such as Thailand, Burma and Malaysia and of course the country where people take their teak forests very seriously, Indonesia. Since the country’s post-colonial era in the mid-20th century, the Indonesian government has designated a corporation that manages the nation’s most valuable natural resources.

The PT Perhutani is in charge of maintaining the official teak plantations found along the lovely Indonesian island of Java. In this place, there are a predetermined number of trees that can be cut each year. Each tree is replaced with a new tree that’s planted in its place in the plantation.

It can take around 80 years for teak trees to mature and be ready for cutting. Which is why it’s important to reclaim teak furniture as well as teak accessories in homes.

Why is teak so valuable?

Teak is prized for its wood as well as its natural oils and rubber. There is an abundance of natural oils and rubber inside the tight grain of the teak wood. All woods have oils that protect the tree like maple and tea tree oil but teak retains its oil and sap even after the tree is felled. Because of this, teak has better naturally weather-resistant properties than any other type of wood.
When teak wood is dried to a proper moisture level which is around 10 percent of its original content the oils and rubber begin to weatherproof the wood. The natural oils provide protection for the wood from dry rot, which is a common problem in old furniture. Oils and rubber protect the heart of the wood from fungi and parasites that can destroy wood.

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Other characteristics of teak

Teak is good for outdoor furniture. As time goes by teak wood goes from a honey brown color to a lovely silvery gray hue. Teak is indeed expensive but you can take the money you would have paid on annual waterproofing and use it to buy beautiful and durable teak furniture.

Teak is also an extremely durable and resilient wood; complete teak patio furniture set could last for many many years. These can even become a priceless family heirloom. The value in teak furniture also offsets the initial costs of teak, especially considering replacement costs.

But not all teak wood is the same. Some teak wood furniture is better than others and some are also inferior. One type of teak, called sapwood is not as robust as other types of teak. Sapwood is named for the outer layer of any tree; the inner layers of the tree are known as the heart.

Trees grow outward from the center, therefore, the natural oils are found in more abundance in the heart. This makes the teak heart more valuable compared to sapwood. This also makes the teak heart more expensive than other parts of the tree.

Conclusion

If you would like to purchase teak furniture then you made a good choice. Original teak heartwood furniture has low water content and is sustainably harvested from the PT Perhutani forestry reserve. You might end up paying for a high price for your furniture, but no doubt that you’ll be satisfied with your purchase over the next years or even decades of using and enjoying your furniture. So don’t just buy teak furniture from any dealer or distributor; do your homework and look for authentic teak furniture.

Teak Wood. Where does it come from? Do you know how long teak wood has been used? Most that have heard of teak wood, usually recognize the name from durable outdoor furniture. This favorite building material has a rich history that is rather impressive. In fact, it has been used for over two thousand years in boatbuilding. Check out these surprising facts about the history of teak wood.

teakgardenindonesia.com

Teak Wood. Where does it come from?

It’s From South East Asia.

Teak wood originates in South East Asia, growing in such countries as India, Indonesia, Myanmar, and Thailand. These countries are ideal for teak wood since they have such warm, monsoon-like tropical weather. Knowing the popularity of teak wood, countries in South East Asia create teak wood plantations so that they can cultivate this valuable resource. Myanmar accounts for nearly one-third of the world’s total teak production. There is also a rapidly growing plantation market in Central America, particularly in Costa Rica, as well as in South America.

People have been utilizing teak for thousands of years.

Originally, those native to the area where teak grew used the sturdy wood to build homes and even tools. As its popularity increased, so did the use of teak. As mentioned, teak has been used for building boats for over 2000 years. Teak wood is currently used to create buildings, ships, bridges, furniture, flooring, countertops and more. Its resilience and longevity as well as resistance to rot, fungi, and mildew, making it a wood choice that has remained popular over the ages.

20 Years and Counting.

Teak is one of the faster-growing tropical hardwoods growing a half an inch per day, yet it still takes 20 to 25 years to grow into ONE mature tropical tree to a stage to be able to harvest. However, companies like Westminster Teak that pride themselves on using only Grade A teak, those trees are 40 years old. The older the tree, the stronger the wood. The longer the furniture you buy will last.

Not only does teak wood have many uses, but it also has a fascinating history. Over the years, teak wood continues to be used as a building material since it has proven to be durable and resistant to rot and pests.

Buy Teak.

Westminster Teak specializes in high-end teak furniture and their steamer chair was rated “Best Overall” by the Wall Street Journal. Westminster offers a lifetime guarantee on all teak furniture, as well as a money-back guarantee that includes free shipping if you’re not satisfied with your purchase. Westminster only uses teak from certified renewable plantations.

For more on the perfect outdoor living check out what Westminster Teak has to offer today via their website as well as Facebook and Instagram.

*Westminster Teak is a client of Trippin with Tara, but as always, all opinions are our own.

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Trippin with Tara

Tara began her blog in 2012 and quickly became an Online Influencer in Travel and Entertainment. Trippin’ with Tara is a lifestyle blog covering all things entertainment and travel, but don’t be surprised by some great food and product reviews in the mix.

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Squared Teak Posts

Description

Here are some pictures of finished Teak Posts in a nice project.

Click on this link to see the price list for 4, 5, 6, 7, and 8 foot long Squared Teak Posts

The price is for each post that is 95 inches long.

There are various thicknesses available. These posts have centerheart or pith. It is normal to have some checking or cracking on these squared teak posts as the center has juvenile wood and pith or centerheart and the outer part of the tree has a different density including sapwood or white wood.

The price that is shown is for a 95 inch
long posts in that size (3 x 3, 3.5 x 3.5, 4 x 4, 4.5 x 4.5, 5 x 5, 5.5 x 5.5, and 6 x 6 inches). If you need a different
length please email or call with dimensions. It is normal to have some checking or cracking on these squared teak posts as the center has juvenile wood and pith or centerheart and the outer part of the tree has a different density including sapwood or white wood.

One teak post that measures 4″ x 4″ x 60 inches long is 6.67 board feet. This post would cost $66

One teak post that measures 6″ x 6″ x 72 inches long is 18 board feet. This post would cost $232

The table above shows the price for 95 inch long posts. If you need a different size then the price is based on the following:

3 x 3 = $7.90 per board foot

3.5 x 3.5 = $8.90 per board foot

4 x 4 = $9.90 per board foot

4.5 x 4.5 = $10.90 per board foot

5 x 5 = $11.90 per board foot

5.5 x 5.5 = $12.40 per board foot

6 x 6 = $12.90 per board foot

If you need squared teak posts larger than 6 inches then please call or send us an email with the specifications.

If the weight is greater than 150 pounds then it cannot be sent via Fedex or UPS ground, then please call or email with details about the delivery location.

Is it a residence or business? Do you have a forklift or a loading dock? Do you need a liftgate on the truck?

We also sell rectangular teak posts.

We have some rectangular teak posts in stock and can always cut more. Please call or email if you need specific dimensions.

We have longer posts but the longest we can send via UPS or FEDEX ground is 95 inches.

Thanks.

Teak Tree Facts: Information About Teak Tree Uses And More

What are teak trees? They are tall, dramatic members of the mint family. The tree’s foliage is red when the leaves first come in but green when they mature. Teak trees produce wood that is known for its durability and beauty. For more teak tree facts and information about teak tree uses, read on.

Teak Tree Facts

Few Americans grow teak trees (Tectona grandis), so it is natural to ask: what are teak trees and where do teak trees grow? Teak are hardwood trees that grow in the south of Asia, usually in monsoon rainforests, including India, Myanmar, Thailand and Indonesia. They can be found growing throughout that region. However, many native teak forests have vanished due to over-logging.

Teak trees can grow to 150 feet tall and live for 100 years. Teak tree leaves are reddish green and rough to the touch. Teak trees shed their leaves in dry season then regrow them when it rains. The tree also bears flowers, very pale blue blossoms arranged in clusters at the branch tips. These flowers produce fruit called drupes.

Teak Tree Growing Conditions

Ideal teak tree growing conditions include a tropical climate with generous daily sunshine. Teak trees also prefer fertile, well-draining soil. For the teak to propagate, it must have insect pollinators to distribute pollen. Generally, this is done by bees.

Teak Tree Uses

The teak is a beautiful tree, but much of its commercial value has been as lumber. Under the scaly brown bark on the trunk of the tree lies the heartwood, a deep, dark gold. It is acclaimed because it can withstand weather conditions and resists decay.

The demand for teak wood is much greater than its supply in nature, so entrepreneurs have established plantations to grow the valuable tree. Its resistance to wood rot and shipworms makes it perfect for building large projects in wet areas, such as bridges, decks and boats.

Teak is also used to make medicine in Asia. Its astringent and diuretic properties help to limit and reduce swelling.

“Super teak” is a fast grown species of teak (Tectona grandis Linn. f) derived from several clones. This has facilitated plantation rotations as short as 5 years. Harvesting of super teak started in 2012. However, no substantive studies of wood properties or suitable utilization options for such young material have been published. This study aimed to investigate wood properties of super teak and to determine the best clone based on an assessment of its wood properties (Part 1). Furthermore, this thesis also aimed to study the relationships between ultrastructural and structural characteristics with wood hardness and dimensional stability, two of the principal wood characteristics governing the suitability of the wood for high value uses. The ultrastructure properties deal with the ‘crystalline’ nature of the wood cells. A further aim was to develop non-destructive methodologies for the prediction of wood hardness and dimensional stability via the shrinkage and unit shrinkage properties of the wood from standing trees (Part 2). In total, the wood properties investigated were physical, mechanical, anatomical, chemical composition, and their implications for wood utilization. Physical attributes included colour, heartwood formation, density, shrinkage, and unit shrinkage. Mechanical properties included hardness, MOE and MOR; anatomical structure included fibre length and ’crystallinity‘; and chemical composition included cellulose, lignin and extractives content. Positive outcomes were identified for super teak. They included high lignin content which was shown to be related to low wood shrinkage. Accordingly, the fast grown wood properties were comparable to those of mature teak. This study provided the basis and the justification that super teak timber is suitable for high value products, that is, furniture and flooring (soft flooring group). The wood characteristics of timber grown from two very different sites were compared. Trees grown on a dry site (East Java) were shown to have larger heartwood zones and significantly higher wood density, compared to wood grown on a wet site in West Java. The higher wood density was shown to result in higher strength properties. Trees planted at the dry site also had higher shrinkage and unit shrinkage. The same responses were observed for the anatomical and chemical properties. They included longer fibre length, lower micro fibril angle (MFA), higher degree of crystallinity (DC), and higher extractives content. A further significant finding was that larger diameter trees exhibited lower shrinkage properties (shrinkage and unit shrinkage) than the smaller diameter trees, and correspondingly exhibited better dimensional stability. Larger trees also had more uniform cell lengths, greater contrast between the wood colour due to the higher redness and yellowness coefficients but they had lower lightness. Larger trees had larger heartwood diameters, higher extractives content and a higher proportion of lignin and cellulose. The most outstanding outcome from this research has been that for the industry driven quest for greater wood volumes; super teak has been shown to provide wood without major drawbacks associated with rapid growth. Therefore, plantation management can focus on growing large trees. In Part 2 of this thesis, the results showed that wood hardness along different structural directions was influenced by different ultrastructural characters of wood ‘crystallinity’. Degree of crystallinity and crystallite width were found to be parameters affecting wood hardness: DC was positively correlated to wood hardness in all structural directions, whereas crystallite width was negatively related to radial and end-grain hardness. Specific gravity was significantly related to wood hardness in all structural directions (r = 0.7 – 0.8). Using exponential fitting to the data, density explained 52 – 56% of the variation in wood hardness. The power of prediction only increased by 1 – 5% when ‘crystallinity’ was included in the regressions, thus when considering wood hardness prediction, wood density is seen to be the most powerful predictor. This has the potential to be developed for non-destructive testing. In addressing the potential of super teak for use as material of high dimensional stability similar to that of mature teak, it was found by statistical analysis that the main wood properties influencing shrinkage and unit shrinkage were density, DC, microfibril angle (MFA), crystallite dimension, and lignin content. MFA and crystallite width were correlated negatively whereas DC was correlated positively. Interestingly, the effect of the wood extractives on shrinkage from super teak was seen to be of little importance compared to that of lignin content since the former was not significantly related to any of the shrinkage properties. A significant negative correlation (r = 0.7) between lignin content and shrinkage was observed. This indicates that increased lignin content was associated with shrinkage reduction. In order to develop prediction models for shrinkage and dimensional stability (via unit shrinkage), mathematical models involving oven dry density, ‘crystallinity’ and chemical content have been shown to accommodate 54 – 87% of the variation of the shrinkage properties. Consequently these models can form the basis for making shrinkage and unit shrinkage predictions. Studies of within tree variability identified that there was no change in basic density, hardness and shrinkage properties with increasing tree height. The implications of this are that wood increment cores can be taken from anywhere in the tree (at any height or radial positions).

Sampled trees and wood sample preparation

Sample trees were obtained from plantation forests managed by the state-owned enterprise, Perhutani, and a local community in Java, Indonesia. The plantation sites were located at Madiun (7° 37′ 4.901″ S/111° 31′ 28.099″ E, 95 m asl), East Java for the Perhutani teak and at Bogor (6° 35′ 23″ S/106° 47′ 29″ E, 127 m asl) West Java for the community teak. Differences in growing conditions (environment, genetics, and silviculture) between West Java and East Java resulted in variations in the teak growth. Bogor, West Java, has a high annual rainfall (average 3500 mm/year), and dry conditions for 2–3 months with an average temperature of 27 °C. Madiun, East Java, has an average rainfall below 2000 mm/year and dry conditions for 4–6 months with an average temperature of 29 °C. Fast-growing clonal seeds have been selected and planted at nutrient-rich sites in the community forest at Bogor, whereas Perhutani has utilized seeds from its production areas, probably from semi-wild provenances.

Three trees each of long rotation and short rotation teak were selected from each plantation site as representative specimens. Defect-free, straight sample trees were selected to minimize tree-to-tree variation. The long rotation trees were 40 years old and 30 cm in average diameter at breast height (1.3 m above ground level). The short rotation trees were 10 years old, 6–10 m in height of branch-free straight bole, and 24 cm in average diameter at breast height level. From the felled tree, a 2-m length basal log was removed and wrapped in plastic, kept cold, and maintained in the green condition before being transported to the wood workshop for preparation of test specimens.

The sample logs were bandsawed in a live sawing pattern to produce pieces with a thickness of 20 mm. The pieces were resawn again to produce timber in sizes of 20 × 100 × 200 mm (radial, tangential, longitudinal). Specimens from the Perhutani teak contained only brown yellowish heartwood, while specimens from the community teak contained light-colored sapwood. The specimens were air-dried to (12–15% m.c. and used for further preparation of smaller samples for studying different wood properties) (Fig. 1).

Fig. 1

The cutting method of wood specimens for tests

Samples of 10 × 20 × 30 mm were prepared for the swelling tests, samples of 20 × 20 × 20 mm for density, samples of 5 × 20 × 200 mm for mechanical tests (MOE, MOR), samples of 20 × 20 × 200 mm for the Brinell hardness test, samples of 5 × 20 × 200 mm for wettability test, and samples of 5 × 20 × 30 mm for durability tests.

Determination of extractive content

Short rotation and long rotation teak wood samples were ground to fine sawdust before drying at 103 °C. Sequential extraction of each wood powder sample, approximately 10 g, was carried out in a Soxhlet apparatus using in sequence four solvents of increasing polarity: dichloromethane, acetone, toluene/ethanol (2/1, (v/v)), and water. After extraction, organic solvents were evaporated under vacuum using a rotary evaporator, while water was freeze-dried. Crude extracts were stored in desiccators under vacuum for final drying and weighed to determine extractive content based on moisture-free wood powder. Dried extractives were stored in a freezer before GC–MS analyses.

GC–MS analysis

A Clarus 680 GC gas chromatogram coupled with a SQ8 Mass Spectrometer (Perkin Elmer, Waltham, MA, USA) was used for this analysis. Gas chromatography was carried out using a capillary column (J&W Scientific, Folsom, CA, USA, DB-5, 30 m × 0.25 mm × 0.25 μm). Two milligrams of dry extract was dissolved in 50–100 μL of N,O-bis(trimethylsilyl)trifluoroacetamide containing 1% trimethylchlorosilane (BSTFA/1% TMCS). The solution was vortex stirred and heated at 70 °C for 6 h. After evaporation of the solvent, the residue was diluted in 1 mL of ethyl acetate. The injection (1 μL) was performed at 250 °C in the splitless mode. Helium was used as carrier gas at constant flow (1 mL/min). Chromatographic conditions were as follows: initial temperature 80 °C, 2 min isothermal, 10 °C min−1 to 190 °C, 15 °C min−1 to 280 °C, 5 min isothermal, 10 °C min−1 to 300 °C, and 14 min isothermal. Ionization was achieved by electron impact at 70 eV ionization energy. Most of the components were identified by comparing the mass spectra with the NIST Library database (2011) with match and reverse match factors above 0.750.

Chemical composition

Holocellulose

The method was performed according to Rowell (2005). 2.5 g of wood sawdust was placed in a 250-mL Erlenmeyer flask and 80 mL of hot distilled water added, followed by 0.5 mL acetic acid, and 1 g of sodium chlorite. An optional 25-mL Erlenmeyer flask was inverted in the neck of the reaction flask to condense vapor. The mixture was heated in a water bath at 70 °C. After 1 h, 0.5 mL of acetic acid and 1 g of sodium chlorite were added. Addition of 0.5 mL acetic acid and 1 g of sodium chlorite was repeated every hour until the residual solid material was turned white indicating the removal of most of the lignin fraction. It usually takes 6 to 8 h of reaction. Holocellulose was filtered on filter paper using a Büchner funnel until the filtrate became colorless, washed with acetone, dried at 103 °C for 24 h, and weighed.

Cellulose

The cellulose was obtained by the Kurschner and Hoffner method using nitric acid in ethanol (HNO3 (16 N), ethanol (95%)) (Antunes et al. 2000). One gram of extracts free sawdust was placed in a 250-mL flask. Forty milliliters of ethanol and 10 mL of nitric acid were added and the mixture was placed under reflux at 100 °C. After 1 h, the alcoholic nitric acid solution was discarded and a fresh volume of 40 mL of ethanol and 10 mL of nitric acid was added. This operation was repeated one additional time. After the third hour of hydrolysis, the cellulose was washed with ethanol, filtered, dried in an oven at 103 °C for 24 h, and weighed.

Hemicellulose

Hemicellulose content was obtained from the difference between holocellulose content and cellulose content. The hemicellulose content was calculated using the following formula:

$$ \mathrm{Hemicellulose}\ \mathrm{content}\ \left(\%\right)=\mathrm{Holocellulose}\ \left(\%\right)-\mathrm{Cellulose}\ \left(\%\right) $$

Lignin

The lignin fraction was obtained by the method of Nguila Inari et al. (2007), which consists in removing polysaccharides. 0.175 g of dried extract free sawdust was placed in a 50-mL centrifuge tube. 1.5 mL of concentrated sulfuric acid (≥ 97.5%) was added to the sawdust. The tubes were closed and placed in a water bath equipped with a stirring system at 30 °C for 1 h. After this period, the mixture was diluted with 42 mL of distilled water to obtain a sulfuric acid concentration of 30%. The tubes were closed and autoclaved for 1 h and 30 min at 120 °C. After autoclaving, the mixture was diluted with 100 mL of distilled water and filtered on a Büchner funnel. The black residue of lignin was dried at 103 °C for 48 h until constant mass. Lignin content is determined by the following formula:

$$ \mathrm{Lignin}\ \mathrm{content}\ \left(\%\right)=\left(\mathrm{Mass}\ \mathrm{of}\ \mathrm{lignin}/0.175\right)\times 100 $$

Density

Density was calculated as the air-dried mass (moisture content 12–15%) divided by the air-dried volume of the sample. Sample dimensions were measured along the radial, tangential, and longitudinal directions using a 0.01-mm precision caliper in air-dried condition.

Swelling test

The method was performed according to Edou Engonga et al. (1999, 2000). Six replicates of short rotation and long rotation teak woods dried for 48 h at 103 °C, cut into samples of 10 × 20 × 30 mm, were measured according to their radial, longitudinal, and tangential directions to obtain the dry volume. Test blocks were soaked in water in a beaker. The beaker was placed in a desiccator and subjected to a vacuum (30 mbar) for 1 h. The samples were left submerged in water for 1 day. After this period, the water contained in the beaker was changed and cycle of soaking repeated four times with change of water between each cycle. Samples were then removed from the water and their dimensions measured to obtain the wet volume. Volumetric swelling of wood was calculated with the following formula:

$$ S=\left\times 100 $$

where S is swelling of wood, VW is wet volume of wood, and VD is the initial dry volume of wood.

Microscopic wood anatomy measurements

Thin transverse sections (12 μm in thickness) were prepared on a sliding microtome. The sections were double stained with Safranin (1%) and Astra (1%). Digital images of transverse sections were captured with a digital camera mounted on photonic microscope and analyzed with the ImageJ 1.47s software to determine the vessel area and vessel frequency (vessel number per unit area). Wood porosity was estimated using the ImageJ 1.47s software as the ratio of vessel area on total area of the sample.

Mechanical tests

Modulus of elasticity (MOE) and modulus of rupture (MOR) were determined with samples of 5 × 20 × 200 mm according to EN 310 using a three point bending device INSTRON 4467 universal testing machine (Buckinghamshire, UK) (European Standard 1993).

The Brinell hardness test

This test was conducted according to EN 1534 on the test samples with a dimension of 20 × 20 × 200 mm (European Standard 2010). The test is performed on each of the tangential and radial faces of the specimens. The ball diameter is 10 mm; a force is applied gradually until its value reaches 1960 Newtons in 20 s, and this force is maintained normally 30 s, then slowly discharged. The measure of the depression gives the Brinell hardness. The Brinell hardness was then obtained using the following formula:

$$ \mathrm{HB}=2\ F/\left\{g\times \pi \times D\times \left\ \right\} $$

Contact angle measurements

The contact angle of teak wood was measured by the optical method using a Krüss model DSA10 (Hamburg, Germany) at room temperature and humidity with water and glycerol as test liquids. Ten drops of liquid were used for each wood sample. For each drop, 11 contact angle measurements were performed automatically (one measurement each 2 s).

Water sorption isotherm

Isotherms were performed using a dynamic gravimetric water sorption analyzer from Surface Measurement Systems (DVS-Intrinsic) (Allentown, USA) on small teak chips previously extracted (first extraction with acetone followed by toluene/ethanol (2/1, (v/v)) or not samples (Simo-Tagne et al. 2016). An initial mass of approximately 10 mg of each sample was used for each measurement. The sorption cycles applied started from 0% RH at 20 °C. Samples were maintained at a constant RH level until the weight change per minute (dm/dt) value reached 0.0005% per min.

Decay resistance (European Standard 1996)

Decay resistance was evaluated according to a procedure modified from EN 113 (1986) described by Bravery (1979). In brief, white rot fungi Coriolus versicolor (L) Quelet (Strain CTB 863A) (Cv) and Pycnoporus sanguineus MUCL 51321 (Ps) were inoculated on sterile culture medium prepared from malt (40 g) and agar (20 g) in distilled water (1 L) in 9-cm Petri dishes and cultivated in an incubator at 22 °C temperature and 70% relative humidity for 7 days. After colonization of all the surface of Petri dishes by the mycelium, three short rotation or long rotation teak samples or European beech samples (Fagus sylvatica L.) used as control were put in each Petri dish and then incubated for another 12 weeks. Dimensions of the samples in this test were 5 × 20 × 30 mm with 12 replicates for each fungus tested. The weight loss (WL) due to degradation by fungus was calculated with the following equation:

$$ \mathrm{WL}=\left\times 100 $$

where WL is the weight loss ratio (%) and M0 and M1 are dry mass of the samples before and after exposure to fungus, respectively.

Color measurements (UV irradiation)

Samples were exposed in a QUV accelerated weathering tester from Q-Lab (Canterbury, USA) for 60 h. Cycle 1 of ASTM G154-2012 Standard test method “Standard Practice for Operating Fluorescent Ultraviolet (UV) Lamp Apparatus for Exposure of Non-metallic Materials” was used. An UV-A 340 lamp was used for the irradiation at 0.89 W/m2/nm to simulate the UV portion of the solar spectrum.

Color measurements using a reflectance spectrophotometer: (X-Rite spectrophotometer). The CIEL*a*b* color scale was used. The overall color differences (ΔE) were calculated using the following equation:

$$ \Delta {E_{\mathrm{ab}}}^{\ast }={\left}^{1/2} $$

Data availability

All data generated or analyzed during this study are included in this published article.

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