Prevalence and Distribution of Fusarium Species in Maize Cultivated across Selected Five Districts in Malawi

Abstract

Maize, as a staple food in sub-Saharan Africa, remains highly vulnerable to fungal contamination especially by Fusarium species known for producing mycotoxins that threaten food safety and public health. This study aimed to determine the prevalence and diversity of Fusarium spp. associated with maize grains across five selected districts in Malawi: Rumphi, Dedza, Salima, Mzimba, and Ntchisi, which lie within three different agroecological zones. A total of 9600 maize grain samples were collected and screened for fungal infection using standard mycological methods. The results indicated high levels of fungal contamination in all districts, with Ntchisi recording the highest prevalence at 16.33%, followed by Salima (15.43%), Dedza (11.39%), Rumphi (11.16%), and Mzimba (11.00%). Chi-square analysis indicated a statistically significant difference (p < 0.001) in fungal occurrence among the districts. Seven Fusarium species were identified across the sampled locations: F. oxysporum, F. solani, F. verticillioides, F. chlamydosporum, F. sambucinum, F. graminearum, and F. avenaceum. Among these, F. oxysporum was the most dominant, especially in Ntchisi (11.11%) and Mzimba (8.43%), while F. solani was prevalent in Dedza. Notably, F. verticillioides, a known fumonisin producer, was detected in all districts except Ntchsi, raising concerns about mycotoxin contamination. The distribution of Fusarium spp. appears to be influenced by environmental and agroecological factors. These findings highlight the urgent need for integrated fungal management in maize production, including pre- and postharvest strategies, farmer education, and periodic monitoring of mycotoxigenic fungi. Further research should focus on molecular characterisation and toxin profiling to assess the public health implications of the identified strains.