It is often seen on the surface of wood a number of
blue—black or blue—grey patches which were originally absent
but developed later if the wood is kept unseasoned in warm,
humid and unventilated places. Sometimes this colour may be
brownish or purple accompanied by smell. This colour or
stain is technically termed as “Sapstain” as it is more
frequent in sapwood than in heartwood. Initially the stain
appears as a tinyblue spot or a small patch or streak on the
freshly cut surface or the end of a log (1). It gradually
and rapidly spreads and becomes deep-siated if some preven— * ‘
tive measure is not taken. Sapstain does not hecessarily
weaken the wood appreciably but it spoils the appearance and
thus reduces the market value. With dark coloured wood, it
is not as serious a problem as with light coloured wood
where the distinguishable blue colour of the sapstain mars
the beauty of the white or light brown colour of the wood.
Except for a few species ( e*g4, teak and sal ) nearly all
our indigenous species are susceptible to attack by sapstain
to a greater or lesser degree any time between a tree is

felled and the converted timbers are’seasoned. It is obser-
ved that light coloured wood is more prone to the attack of

sapstain and as such it is common with satian (Alstonia
narikeli (pterygota alata), chundul (tetrameles

pitali (trewia nudiflora), kadam(anthbcephalus kadam-
scholaris

nudiflora/, uxcwxd uuuxxxuxa;, itaaaui^auxnocepnaxus Jtaaa
ba)t am(yiengifera* dndica)^uTiem(Mehgifera sylvatica)v, civit
iswintonia floribunda), etc. Most of these species are
industrially important and are used in Bangladesh for the
manufacture of safety match, veneer, tea-chest plywood and
battens, doors and windows etc. As such proper .understanding

of the causes and preventive measures of sapstain are essen-
tial to preserve and optimally utilize, our scarce timber

resources.