Rusli MH, Idris AS and Cooper RM
Vascular wilt disease caused by Fusarium oxysporum f. sp. elaeidis (Foe) causes a devastating disease of oil palm in West and Central Africa. However, this disease is a major threat to the Malaysian oil palm industry as it has not been reported in Southeast Asia, in spite of long term importation for breeding purposes of African seed and pollen, known to be often contaminated with Foe. This study shows that disease progress was substantially delayed/reduced in two non-autoclaved Malaysian soils compared to autoclaved Malaysian soils highlighting the possibility that Foe-suppressive soils in Malaysia might explain the non-appearance of this vascular disease there. This coincided with the limited presence of Foe in non-autoclaved soils compared to high presence of Foe in root (>145 cfu/g), bulb (>75 cfu/g), leaf 1 (>100 cfu/g) and leaf 3 (>60 cfu/g) of autoclaved soils. Population density of Fusarium spp. was also significantly greater in sterile soils compared to non-autoclaved soils. From this study, endophytes were also isolated from various parts of oil palm seedling inoculated with Foe and growing in Malaysian soils; showed degrees of antagonism towards Foe with 10 out of 15 isolates recording more than 50% inhibition