Fusarium wilt, caused by the soil-borne fungus Fusarium oxysporum f. sp. cubense (Foc), poses a major threat to banana production globally. A variant of Foc that originated in Southeast Asia, called tropical race 4 (TR4), was detected on a Cavendish banana export plantation (Metocheria) in northern Mozambique in 2013. Foc TR4 was rapidly disseminated on the farm, and affected approximately half a million plants within 3 years. The fungus was also detected on a second commercial property approximately 200 km away (Lurio farm) a year later, and on a small-grower’s property near Metocheria farm in 2015. Surveys in Mozambique showed that non-Cavendish banana varieties were only affected by Foc race 1 and race 2 strains. The testing of Cavendish banana somaclones in northern Mozambique revealed that GCTCV-119 was most resistant to Foc TR4, but that GCTCV-218 produced better bunches. The occurrence of Foc TR4 in northern Mozambique poses a potential threat to food security on the African continent, where banana is considered a staple food and source of income to millions of people. Cavendish somaclones can be used, in combination with integrated disease management practices, to replace susceptible Cavendish cultivars in southern Africa. The comprehensive testing of African cooking bananas for resistance to Foc TR4 is required, along with the improvement of biosecurity and preparedness of growers on the African continent.

In Africa, oil palm is grown in 25 countries supported by corporate investors. In Uganda, commercial oil palm cultivation began in 2005 in Bugala Islands. Seedlings were imported from countries with established breeding programs. These seedlings were grown in areas with different environmental conditions which have resulted in a number of physiological disorders. The aim of this research was to determine the major physiological disorders in oil palm fruit bunches in Uganda. The study was carried out in the adaptive trials in Kagadi, Bugiri, Buvuma and Masaka Districts and in the different smallholder farmer blocks in Kalangala District. Data was collected on bunch rot, bunch failure and uneven ripening. Sampling was carried out in oil palm plantations above five years of age. Three fields were selected from each unit and three units from each block by the help of the Agricultural Extension Officers (AEOs). Palms were randomly sampled and assessed for presence of bunch rot, bunch failure and uneven ripening symptoms. The incidence was expressed as a percentage of the total number of palms sampled while the severity of bunch rot disease was scored on a scale of 0-4. From the results, the differences in bunch rot and bunch failure in adaptive trials were statistically significant as well as across seasons (P < 0.05). Uneven ripening was not statistically significant and severity of bunch rot in the different farmer blocks in Kalangala was statistically significant (P = 0.03). Uneven ripening was high across smallholder farmer blocks in Kalangala and was statistically significant (P = 0.05) even across seasons (P < 0.05). These results are important for sensitization of farmers on management of oil palm disorders and essential for guiding policy makers and investors as the oil palm industrial sector is being developed in Uganda. This study calls for determination of water deficit at the various ecological zones and its relationship to physiological disorders as a guide for further oil palm estate development.

Fusarium wilt of oil palm is caused by Fusarium oxysporum f. sp. elaeidis and is particularly prevalent in Africa. This study was conducted in Kalangala district, the commercial oil palm cradleland in Uganda and it involved undertaking a survey among smallholder farmers to assess the occurrence, distribution, farmers' knowledge and management level of Fusarium wilt of oil palm. This was achieved by taking an inventory of all the plants in a given plot, noting the presence or absence of symptoms of Fusarium wilt and calculating the incidence in each given plot. This is the first time Fusarium is identified in oil palm plantations in Uganda and the results showed that infected trees were mainly found in Mugoye sub-county, Kagulube block. The highest average severity (3) was observed in Kagulube as compared to all other blocks (severity score 2). The highest percentage incidence (15%) was noted in Kagulube and the least (5%) in Bbeta East, Bbeta West and Bujjumba blocks. Despite the widespread occurrence of Fusarium wilt in Kalangala, management of the disease among farmers was inadequate. Urgent measures need to be undertaken to prevent spread of Fusarium wilt within and among farmers' fields.

Oil palm, a lucrative vegetable oil crop in the world, showed promising adaptability to some agroecologies in Uganda from studies carried out in the 1970s resulting in first commercial establishment in 2005 in Bugala Island, Kalangala district. Further, adaptability studies continue to reveal suitable areas for commercial oil palm production in the country. The infant industry faces an array of challenges, both biotic and abiotic especially in regard to smallholder farmer field management and build-up of pests and disease in the face of climate change both in the nuclear estate and smallholder farmers’ fields. The rapid build-up of devastating diseases such as Fusarium wilt of oil palm and Ganoderma trunk rot in Uganda is an interesting scenario since they are often expected from second-phase plantings in other areas in the world. However, it may be attributed to the all-year-round weather suitability to pests and disease build-up on native or alternative hosts in most agroecologies in Uganda. This difference from other oil palm producing regions in the world has resulted in recently initiated oil palm Research in Uganda to focus on developing local solutions to challenges facing oil palm farmers in the country.