Identification of a pathogen affecting oil palm in Sarawak, Malaysia

Abstract

A petiole wilt disease was first observed affecting oil palm (Elaeis guineensis) in the Sibu area of Sarawak in 2013. The disease has now spread widely in this area and has also been recorded in the Miri district. Disease symptoms were observed as a progressive die-back of the leaf, beginning with the tip and making its way down towards the petiole, with lesions also present along the leaf stem. The disease eventually results in the destruction of the entire leaf and ultimately destroys fruiting capacity in infected plants. Pure cultures were isolated from lesions on diseased oil palms. The pathogen was identified as Ceratocystis paradoxa based on morphological characteristics and DNA sequence data. The species has a wide distribution in the tropics and has been previously reported from oil palm, causing the diseases known as dry basal rot in Africa, and common spear rot in Indonesia. The pathogen also causes black seed rot in sprouted oil palm seeds, which has resulted in major economic losses in oil palm production in Nigeria. Biological control using endophytic Trichoderma may provide a means of controlling the disease in oil palm.