Incidence of basal stem rot disease of oil palm in converted planting areas and control treatments

Abstract

The incidence of BSR was observed over years in 4 historically-different planting areas i.e. land converted from rubber, cacao and swamp, and continuous oil palm replanting area. In addition, we observed the effect of surgery-mounding to the lifetime of Ganoderma-infected palms and the effectiveness of different replanting techniques on the incidence of BSR disease. The infection rate of Ganoderma was faster in oil palm replanting area at 7.68% per yr, followed by land conversion from swamp, cacao, and rubber at 4.67%, 3.81%, and 1.06% per yr, respectively. Surgery-mounding of Ganoderma-infected palms can prolong the lifetime of the infected palms with number of death palm up to 4.45%. Meanwhile, removal of Ganoderma inoculum sources during replanting contributes to lower BSR incidence in the first nine years. The lowest incidence of BSR was observed following the complete removal of oil palm debris in combination with big-hole planting system with less than 5% infected palms. On the other hand, the incidence of BSR on the individual use of big-hole planting system during replanting was at 6.29% at 9 yr after planting. The result suggests the importance of inoculum removal during replanting to prevent Ganoderma infection in the early phase of oil palm development.