BioassaysHevea brasiliensis leaves (clone PB260, sensitive to Corynesporacassiicola strain CCP) in the morphogenetic stage D [13]were detached and placed on water-soaked filter paper in large Petri plates, abaxial side up. The lower epidermis was gently scraped (over 1mm2) using a scalpel blade and one drop of the tested sample (10 or 15l) was placed on the superficially wounded spot. Drops of chromatography buffers were used as negative controls, in appropriate dilution to, reproduce the solution of the tested sample after elution. The plates were maintained for 48–96 h at 25 ◦C (photoperiod 12 h) until symptoms were clearly visible.