A possible role of Cyanogenesis in the onset of tapping panel dryness of rubber (Hevea brasiliensis). In: Agrotrópica v. 15 p. 103-106, 2003.

Abstract

The primary cause of Tapping Panel Dryness (TPD) of rubber trees is still unknown. In a preliminary assay of the role of cyanogenesis as a cause of TPD, hydrocyanic acid (HCN) was released from open punctures and retained in the bark in sealed punctures, which were reported to induce bark dryness. More HCN was released after refoliation, at the leaf stage C, than during leaf senescence. This is in accordance with reports of high TPD incidence after refoliation. Moreover, a role of cyanogenesis could explain TPD occurrence in trees only recently brought into tapping, or its induction by bark compression. The induction of dryness by punctures was only incipient, but the symptoms were similar to the described for Brown Bast. The possible role of cyanogenesis in the onset of TPD deserves therefore further research.