Wood does a lot of good

-- (Credit: Vishwajyoti)A FUNGUS that virtually eats into every
conceivable part of the, rubber tree -
Hevea brasiliensis - has finally met its
match in an environment-friendly
deterrent. Researchers from the Rubber
Research Institute, (RRI) in Kottayam,
Kerala, have developed a new ecofriendly fungicide from wood extracts of
five locally available tree. Currently,
highly toxic chemical fungicides are
sprayed to contain the deadly effects of
the fungus.

The fungus, Phytophthora, is quite a
killer. In rubber trees, it causes, among
others: leaf fall, a serious disease causing
crop loss in susceptible clones; 'bark rot'
or 'black stripe' that affects the bark of
the tree being tapped during rainy seasons; 'patch canker', which affects the
stem; 'shoot rot', which causes havoc in
nurseries and immature plantations,
and 'pod rot' that can reduce the
number of healthy seeds, in seed
collection centres.

Dubbing their finding as "the first of
its kind", L Thankamma and M Jayadevi
of the RRI report that water extracts from
the heartwood of species such as rosewood, anjily, teak, jackfruit and
enterolobium or the rain tree, have
remarkable anti-fungal properties
against Phytophthora. It,was observed
that the heartwood of these trees
were able to withstand bio-deterioration or decomposition induced by living
organisms.

This naturally led researchers to
test heartwood extracts to create
safe fungicides. Detailed laboratory
studies showed that polyphenols -
chemicals that impart a dark colouring
to heartwood bear fungicidal
properties which could keep
Phytophthora in check. "Though this is
an in, vitro study, it has got high potential. If successful in the in vivo studies
also, it will be a boon.in the field of
disease management," reflect the duo
hopefully.