MORPHOLOGY OF Phytophthora SP. CAUSING STEM CANKER IN NUTMEG AND THE ROLE OF ACTIVATED CHARCOAL AS A BIOLOGICAL CONTROL AGENT

Abstract

Nutmeg (Myristica fragrans Houtt) is one of Indonesia's leading spice commodities with high economic and export value. However, its productivity has declined significantly due to stem canker disease. The study aimed to characterize the morphology of Phytophthora sp and evaluate the effectiveness of activated charcoal from coconut, pine, and walnut shells in suppressing stem cancer disease. Surveys were conducted in several nutmeg centers on Ambon Island. The evaluation of activated charcoal effectiveness was carried out in situ and in vitro. The results showed that coconut shell charcoal was more effective than pine and walnut charcoal. The results also showed that the Phytophthora sp species found was a new subspecies and morphologically different from the previously known Phytophthora sp. It is hoped that the results of this study will contribute significantly to the environmentally friendly management of nutmeg stem cancer and support the increase in productivity of smallholder plantations.