Detection and spread of Fusarium oxysporum f. sp. elaeidis among small holder farmers in Kalangala district, Uganda

Abstract

Fusarium wilt of oil palm is the most devastating disease of oil palm in Africa. It’s caused by Fusarium oxysporum f. sp. elaeidis, a soil borne pathogen that spreads through root contact, movement of infested soil, farm tools and plant materials. In Uganda, symptomatic palms were first observed in late 2018 in Kalangala. A study was conducted to confirm the disease and to monitor the trend of the disease in different production blocks in Kalangala. Plots of 100*100 m with typical Fusarium wilt symptomatic palms were selected for the study. Data on severity and percentage incidence was collected periodically from the marked plots. Stem, frond, root and soil from the marked plots was collected for pathogen analysis. Fusarium oxysporum f. sp. elaeidis was confirmed as the cause of wilts in Kalangala. After a period of 39 months, the periodic percentage incidence and average severity showed that Kagulube block was worst affected with an average severity score of 3.2 and percentage incidence of 8.5%. The soils in Kagulube were typically sandy (over 80% sand and less that 13% clay) compared to other areas (below 80% sand and over 20% clay). Sandy soils have poor nutrient retention capacity and are easily washed away under poor soil cover accelerating spread of the disease in the affected areas. The occurrence of Fusarium wilt of oil palm in Kalangala poses a threat to the growing oil palm industry in Uganda. With research in its initial stages, comprehensive testing of imported oil palm varieties for resistance to the local strains of Fusarium wilt before wide scale planting and adoption of best agronomic practices can offer a sustainable solution to Fusarium wilt in Uganda.