Wood does a lot of good

It was the bane of the rubber tree, as the fungus Phytophthora literally ate into its every part. With the discovery of antifungal wood extracts, however, the fungus can be stopped dead in its tracks. The extract also meets today's criterion of ecofriendly fertilisers, being purely natural in its origin
Wood does a lot of good

A FUNGUS that virtually eats into everyconceivable part of the, rubber tree -Hevea brasiliensis - has finally met itsmatch in an environment-friendlydeterrent. Researchers from the RubberResearch Institute, (RRI) in Kottayam,Kerala, have developed a new ecofriendly fungicide from wood extracts offive locally available tree. Currently,highly toxic chemical fungicides aresprayed to contain the deadly effects ofthe fungus.

The fungus, Phytophthora, is quite akiller. In rubber trees, it causes, amongothers: leaf fall, a serious disease causingcrop loss in susceptible clones; 'bark rot'or 'black stripe' that affects the bark ofthe tree being tapped during rainy seasons; 'patch canker', which affects thestem; 'shoot rot', which causes havoc innurseries and immature plantations,and 'pod rot' that can reduce thenumber of healthy seeds, in seedcollection centres.

Dubbing their finding as "the first ofits kind", L Thankamma and M Jayadeviof the RRI report that water extracts fromthe heartwood of species such as rosewood, anjily, teak, jackfruit andenterolobium or the rain tree, haveremarkable anti-fungal propertiesagainst Phytophthora. It,was observedthat the heartwood of these treeswere able to withstand bio-deterioration or decomposition induced by livingorganisms.

This naturally led researchers totest heartwood extracts to createsafe fungicides. Detailed laboratorystudies showed that polyphenols -chemicals that impart a dark colouringto heartwood bear fungicidalproperties which could keepPhytophthora in check. "Though this isan in, vitro study, it has got high potential. If successful in the in vivo studiesalso, it will be a boon.in the field ofdisease management," reflect the duohopefully.

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