cr&'st r & -" ~
1 . .C
APIT ". ,
I;;G. C, hG
GyJ u' J-T .T I ...I..-.
T 'terocar-us s .
L iVIS L0fl Cl 1f "t~rK
B y *-.. ..... \) ' h ,b ~"
'- .-^ '.7:TY forest P~roducts C'ccl .... "st
z^iwsIcTI of SilviculItural ilclat..-o:-is
in the areas- where it occurs, the Di terocarp faJly, w. th 1 :.cra and
nearly 400 s2 ecies, fills thie -,)lace in timber reduction tuat i.s 'c -u eI
Sstoods, oaks, and otier feazi liar species n te Iorti _rte
Tis Indo-ia"... family extends eastwa:rd into ,cv Cuie an". e !il n*s1
and two :'.u'1"' occur to tie west in te ;eychelles I r!,.s aand -r: a.. I
* 'ica (1) c tipterocar)s are made u mainly of seces thct a.re .i
for producinC ver: li trees, often in nearly ure stands ()
The -enuo Di terocar-us, to wh-ic a-;.t, ., cl ao ..t '' sci
I _'c ,'-u T S .,
* la:i,-' trees. evenn are found in Ind, Ceylon, 1I in t e ...'-e
Isl":.. where tl ey rate as tle coc-t ab,. t .t stuctralI ti:uecr, or :r in
.cr]neo (12), and s.ome oo ot.ers .i the 'lay 'einsula tu e
Archipelago (4 y, 3, 2, 5,_).
1.._.-1?d at 1a 1.son, ) s., in coo- ration wit' t:e i .versity of cnsin.
-U.dierlined nucoers in parentheses refer to the list o. n.u' ered r eerences 5t
the e.. of the article.
Pe-.~'rt :'.'. B .'. ) -1- "culttre-.*h~diron
.......... hi i- fh T
A-itong, as known commercially, may be the product of not less than 15 species
of the genus Dipterocarpus (1). The most common species are D. grandiflorus
Blanco (= D. tuberculatus Eoxb.), D. lasiopoOdus Perkins, and D. vernicifluus
Blanco (, 17.
In addition to apitong, which is a conmmaon name in the Philippines, a numbrfoer
of other trade and vernacular names are often applied to these woods. These
include eng in India and England (9, 21), gurjun in Burma, keruing in the
IMalay Peninsula, hora in Ceylon, and yang in Siam (4, 2, 34).
Dipterocarpus grandiflorus Blanco (= D. tuberculatus Roxb.) may be considered
as a typical species of the group of woods called apitong. it is one of the
most generally known and widely distributed.
The trees may attain a height of 50 to 155 feet, often with 50 to 90 feet of
clear, straight, cylindrical bole before the first branches. Girths of 8 to
15 feet and diameters up to 90 inches have been reported. The trees have
comparatively small buttresses (1, 4, 5, 14, 21).
The deciduous (8) leaves are leathery and smooth (30).
The fragrant flowers are white or pink in color (51).
The fruit is one-celled with two large outwardly curved wings (51).
The bark may be 3 to 4 inches thick, brittle, and light gray to dark brownish
gray. It sheds off in large scroll-shaped plates and bears many corky
lu-tules; the inner bark is reddish. Resin used for varnish, torches, and
boat caulking exudes when the 1/2-inch inner bark is cut. The ends of the
logs tend to be resinous and "tacky" (4_, 5, 14, 31).
Report 7-. 11920
The woods of the different species called aitcng are so siric.lar t-iat it is
difficult to distinguish one s )ecies lOtIer (e.
T sa wood, 3/4 to 5 or more inches in thickness, nay be two-:.oncd; the
outer zone may have a crez-.iy-yellow, gv':,, or reddish-white color t at sViadcs
into reddis- purple or bro. (4, 5). ''Ie sa wood tones into the darker
.en o red _. ,-1 ". ..4 1
r -e s-or... I.sh -brow- hecartv'oc., wl.ic'i darkens on ox'osure (_, _, l4, 1,
Grain, Te::e-t',.c and Figure
Apitong wood mnay notably iave fairly strai ht Crain, bit it iay also be
shallovly interlocked or cross grained. Its even texture is fine to rather
coarse R, 5, II 14, 21, 26, 54).
Apitong is not a lustrous wood (15, 26).
Odor and Taste
The wood has a slightly pleasant resinous odor but no distinct taste (11, 14,
The weij.t of auitona, depending on its moisture content, ranges from n- to 6
pounds per cubic IoVt with a usual range of 40 to 57 (ounds (4, ', i., 1,
Thecific gravity values fro.i 0.60 to 0.6 ]w:v: been reported (, 14, 15, 2L,
,!e.-c j""cal Properties
Strength valucz of amiton,- determined on material froir. different localities
in the Philipines varied considerably. Tie stron;-r t wood was that wits the
highest density (1, 7). Test data from so:ie early liilip. ,. tests (6) have
been tab'".t",.d in table 1, wiic]h lists values for some :r erties of rcc:-. and
Rep,,ort Rl. P. :o
Table l.--Physical and strength properties of green and air-dry apitong from the
i Green2 :Air-dry (adjusted
: : to 12 percent
2 :moisture content)3
- -- - - - - - - - - - - - - - - - - - - - - -: - - - - - - -
1loisture content.. *..... ... ... *..*.**. .percent:
Specific gravity -- volume as tested.............:
Shrinkage, in volume -- green to oven-dry..percent:
Shrinkage, radial -- green to oven-dry.......,.do.:
Shrinkage, tangential -- green to oven-dry.....do.:
Fiber stress at proportional limit........p.s.i.: 5,000
iIodulus of rupture......................9...do.: 9,OO
olodulus of elasticity...........*....1,000 p.s.i.: 1,9LO
Vork to proportional limit...in.-lb. per cu. in.: 0.77
Uork to maximum load..,..................do. 7.67
Compression parallel to grain
Crushing strength at proportional limit...p.s.i.: 3,300
MJaximumn crushing strength...................do.: ,500O
Compression perpendicular to grain
Crushing strength at proportional limit......do.: 680
End.. ... ........ ..... ........ ................Ib. 870
Radial. o..... . .. .. . . ... ... do...I
Tangential........... .............. ... .. .do.J 780
Ce. e .C C e CC. CC C .e 6.
e.. *..O* O oe .e ...
* lL .8
Radial..... ..... .. l
TangE-(ntial ........... . o .. . . . ,o .1 1
iTao.e roepared by John T. Drow, Timber LRcL e.ics Division,
U. S. Forest Products
I2Data on green material from "Comparative Strength Properties of the Principal
Phllippine Commercial roods,!" by Jose C. Espinosa, Phil. Jour. Sci. Vol. 33,
No. L1, 927.
2iata on air-dry material from same source as data for green material but ad-
J "rom 17 to 12 percent moisture content on th} basis of tl-e usual
e; L:ntial relationship, ass .:,.. an "intersection point"' of 25 percent mois-
LShrinkarge data are approximate, representing the sum of shrinkig'- values from
gre.n to air-dry and air-dry to oven-dry, as reported in Phil. Bur. For.
Techo Bull. No. 7I, Appendix 6.
-Loacd to imbed a O.hli-inch steel ball to 1/2 its diameter.
Report Mo. R1920
air-dry material. These data were obtained fro:,.a sp>ecimens of t c sies used
for Forest productss :.r- .r:tory tests. 1hey have oeen convert:.. 4 ro:.. L;etr-
systeu.. units a: aK.htsted to 12 percent moisture content to iLr'he tiem co:n ara-
ble to de.ta available on familiar Unted states s ecies. Other test data 'rom
-..v.!., I'laya, and the 7 iliiines have been re orted else ere ut are based
on s r-2imens of different sizes with different no:Lsture content values or are
in different units (10, 15, 2, _, ).
Comre'ensive seasoning information is not ava able for a ptons. The range
of variation in density and resin content of the material oid Ln world markets
as a-itong is considerable. ILt is believed, however, tlat wit. the careful
use ,, modern r""-ino met odls a-itong can be adequately seasoned, in s ite of
the fact that -t -as had a re mutation for being slow to dr and so.ew at rer-
tory with notable tendencies to warp, check, s lit, and coll :e (, 5, 21).
Lir seasoning (2) or air seasoning prior to kiln rying have .ot. been used
wilt. this material.
The British -orest products Research Laboratory hias recom:endc d reltitel
mild treatment for apitong, starting with temperatures of llu i or 127 I. and
' percent relative humidity (Cchedules ,os. 4 and 5, leaflet ',o. 42, "Kiln
Drying Schedules," 1 4). T..e U. S. Forest Products Laboratory _n its ip51
"Schedules for the IKiln DryIing of hood" (Forest Products LaborLtcr. e ort
No. 9171l) lists as a generally a-plicable fild sci:edule, TJ-Il, which nras been
sup-'.-ted for use with f- a apitong. Sc-iedule T5-C2 in tillis report rould pro-
vide a ..-'e severe schedule if conditions aLpeared to warrant it.
As an effective general procedure for minimizing waring, a sticker s-acinv' of
not over l8 inches, with all stickers in vertical alineiient, and weighting down
of the top of the pile has been used.
Shrinhage figures recorded (26) for apitong are:
Rladial Tap. :ential Longitudinal Volumetric
(ercercen t) recent) 7 7rce11.7, percentt
Green to air-lry 2.5 6.7 U.1I .U
.. r-dr' to oven-dry 2.6 4. .1 7
horhI r.,; characteristics vary, considerably a:.on- the different s ecies of
Dij'lT' '-ur-'._ us and even witliin the sane species, as influenced L rowth
conditions. The woods are generally considered as :-,odeirately dl..'icult to
work. 7 -- presence of silica (4, _e) and .uo. cay ve some trouble from
blunt.`..- of cuttin- edges or clop ing of saws (5, _. __-). p. g finisu.
ei, p)olis, however, can be rs n<- es, l il t ts;, foourl ed l:rterial
(114, 21). "xceptionally resinoius iam3terial is tr'ulesoi, for example, n
Rfer..rt '"o. 120
flooring (4i, 5), and in the tropics some staining and corrosion have been
reported where the wood wras in contact with iron (4, 5).
Dipterocar-us species are rated as only moderately durable in exposed posi-
tions For example, untreated railway ties in India lasted only 4 to
5 years and house posts only about 1 year (21). Woods froil these species
serve well for interior work, but need preservative treatment if used in
contact with the ground. They absorb preservatives readily, however, even
with opmen-tank treatment (4, 5, 14). The heartwood of apitong has been
reported as resistant to dry-wood termites and powder post beetles (21).
Heart checks or shakes, oil shakes, end splits, and surface checks sometimes
occur or develop during seasoning of apitong (4, 5). Except for the fact
that the sapwood is not decay resistant and is attacked by beetles (12),
these woods are comparatively free from defects in the logs. The logs) how-
ever, should be removed from the woods as soon as possible after the trees
are felled. Resin sometimes exudes over the surface of sawn material and a
dulling effect on the cutting edges of woodworking tools has been noted (12).
Apitong is used in construction where hard and heavy timber is required.
Its uses include "posts above stums," beams, joists, rafters, partitions,
flooring, mine props, bridges and wharves, poles and. railway ties
(with preservative treatment), wagon beds, automobile framing, framing of
barges and lighters, boats, carts, boxes, railroad cars, and medium-grade
furniture (9, 21, 26).
.Apitong is reported as one of the most abundant structural timbers found in
good sizes in the Philippines. Volumes of 1,000 to 14,000 board feet per acre
hsve been reported (55).
Groirth rings are not distinct. Pores tend to be rather evenly distributed,
rounded in shape, open, and somewhat isolated. Bays are of two sizes (0)
but aproar to be few in number and narrow. Resin ducts are diffusely scat-
tered and surrounded by bands of parenchyma (14, 26).
Report Fo. ER1920
M inor Products
ConsiC.ercble ciuantities of oleoresin (:i:w'. keruin;) are cont.: in tc
wood. 'I e resin rma" exude over ti e ends of and is soeties coll ctd
in holovs Lacked in t'.e tree trunks, It is used for . ; boats a:.d fo
medicine ( .
Report Tio. Ell ..0
1. Aguilar, Luis
1939. The Lechanical Properties of Apitong from Tayabas Province and
Negros and Basilan Islands. Phil. Jour. For. Vol. 2, No. 2,
2. Asiddao, F,
1938. Air-drying Rate of One- and T-o-inch Apitong Boards Under Open
Shed. Phil. Jour. For. Vol. 1, No. 3, PP. 283-291.
3. Clarke, S. H.
1937. Gurjun, Apitong, Keruing, Kapur and Allied Timbers. Forest
Products Research Records :o. 16 (Timber Series No. 5), pp. 11,
1 pl. London. (Rev. Tropical T'oods No. 51, p. 30.) (Rev.
by Arthur Koehler, Jour. For. Vol. 37, No. h, p. 353, 1939.)
h. Desch, H. E.
1lLl. Dipterocarp Timbers of the Malay Peninsula. .Ma!ayan Forest
Records No. l1, pp. 62-75, illus.
19l1. Manual of Malayan Timbers. L'alayan Forest Records Vol. 1,
No. lr, pp. 101-108.
6. Espinosa, Jose C.
1927. Comparative Strength Properties of the Principal Commercial "Voods
of the Philippines. Phil. Jour. Sci. Vol. 33, No. h, Pp.
1i2b. StruigtIL Properties in Relation to Specific Gravity of
Fhilippine 7oods. Phil. Jour. Sci. Vol. 36, No. 1, pp. 55-69.
8. Fcxi-orthy, F. W.
1927. Commercial Timber Trees of the Malay Peninsula. Malayan Forest
Records No. 3, pp. 4l-h4. Singapore.
9. C>m!rle, J. S.
1922. A Manual of Indian Tiribers. 2nd. ed., pp. 70, 72. Sampson
Low, Marston & Co., Ltd. London.
10. Gardner, Rollan
1906. Mechanical Tests, Properties and Uses of Thirty Philippine .o'ods.
Philippine Bur. For. Tech. Bull. Uo. h (Manila).
11. Howard, A. L.
19)48. A Manual of the Timbers of the World. 3rd ed., pp. 30-31,
17h-175, 196-200, 291, 648. I.cniillan Co.
Report /;. R1920
12. Keith, II. G.
1lL7. Timbers of North Borneo. Fp. 29-33. Honr Kong.
13. Kent, H. T. M.
191 0. Report on th, R.esults of U e.hani il Tests Carried OI onU Some
Malayai iironers. Con t'rvator of l'orests, Kuala Lia o ur.
l4. Kr'- ir, J. Hugo
1- 1. T: cs of te 1"ostern Pacific R.gion. Pp. 27'-?77. Tri-S te
Offset Co., Cincinnati, 0(1.o.
!'. Krib-s, D. A.
195' 3. Co-:.x.rcial Foreigni Woods on the American Market. P. (lus.)
SeIool of Forestry, Pennsylvania State C'oc1 .
16. L'w2'., Geor-e :i.
19. Dioterocarpaceae. '*Too1 Products Vol. o. 2, p. 3
17. lierrill, E. D.
1 -3.En'neration of P. J. lz .in Flowerin, Plarints. Vol. 3, p:) -.
S.-.. ,. rraphy of Pwilimine B -tany. Ernmeration of Pilt-i:e
Flo erin" Plant.. Vol. h, pp. l_5-23.
I' . L !'.t Life in the F-ific ororld. -' 8,-8-. Macnillan C.
2C. :.: tcalfe, C. 1. and Chalk, L.
1 3. A:.at of t e Dicotyledons. P-p. 212-220. Clarendon Press,
Oxf or ', Enl and.
21. Pc..rson, R. S. and rTrorn, H. P.
1932. Commercial Timbers of India. Vols. 1 and 2, pp. 67-70, 81-,
illu (fany refs.) Govt. of India, Calcutta.
22. Rcinkin.-, A. 0. and H,.: hrey, C. J.
1931. Laboratory Tests on the Durability of P ili'1rie Wo)ds Aacnst
Funri.- Phil. Jour. Sci. Vol. ^, o p. 77"9 1
7:pical VC, No. 27, p. 14.)
23. Reyes, Lui J.
1923. 'Woods of the Philippine Dipterocarps. Phil. Jour, Sci. Vol. 22,
No. 3, pp. 291-3L, (321-322).
19 '. ii.Jng (Dipterocarrmus s ) of Northe'-. Nc'ros. l+lkilinr
Echo (!.T: T7' :. I'.. L, ':. 27-3i. (Rev. T.-.', ical 7oFds
t'o. 22, pT. 1.-16.)
Report .;o. R1920
1930. Characteristic Figure in Philippine Woods. Timberman (Portland,
Oreg.) Vol. 31, No. 12, pp. 99-100, illus. (Rev. Tropical
Woods No. 25, p. 30.)
1938. Philippine Woods. Philippine Bur. For. Tech. Bull. No. 7 -
(Manila), pp. 3h, 280-286, 288-296, h4h, h57, h67, h70, h80. '
__________ and Aguilar, Luis
193L. Properties and Uses of Common Philippine W'oods. Mailing Echo __
(Manila) Vol. 13, No. 3, pp. 139-17h. (Rev. Tropical Woods
No. hO, p. 52.)
28. Salvoza, F. M. and Lagrimas, !Tartin
19h0. Check List of the Trees of the Philippines With Brief Notes on
Their Uses. Phil. Jour. For. Vol. 3, No. h, pp. h77-5h7, hth
29. Schneider, E. E.
1916. Commercial Woods of the Philippines. Their Preparation and Uses.
Philippine Bur. For. Tech. Bull. No. lh ('anila), pp. 163-16h.
30. Scott, C. W.
1932. Tests in the Rangoon River on the Damage by Marine Borers to
Various Woods, Including Burma Teak and British Guiana Green-
heart, Creosoted and Untreated. Burma Forest Bull. No. 28
(Econ. Ser. No. $) Rangoon, pp. 10, illus. (Rev. Tropical
Woods No. 30, p. $2.)
31. Symington, C. F.
194l. Foresters' annual l of Dipterocarps. Malayan Forest Records,
No. 16, pp. 153-166, 178-180. Kuala Lumpur.
32. Tamesis, Florencio
1927. Annual Report of the Director of Forestry of the Philippine
Islands for the Fiscal Year Ended December 31, 1926. Pp. 292.
Manila. (Rev. Tropical Woods Nod lh, p. h$.)
33. Thomas, A. V.
193h. Result of Mechanical and Physical Tests on Fully Air-dried
Timbers. Malay Forester Vol. 3, PP. l1-17.
34. Timber Development Asso., Ltd.
Some Commercial Timbers of Malaya. Timber Information Ref.
3$. \'hitford, H. W.
1911. The Forests of the Philippines. Forest Types and Products.
Philippine Bur. For. Tech. Bull. No. 10 (Manila).
Report No. R1920