Abstract:
Maize is the most widely cultivated and major security crop in sub-Saharan Africa.
Three foliar diseases threaten maize production on the continent, namely
northern leaf blight, gray leaf spot, and southern corn leaf blight. These are
caused by the fungi Exserohilum turcicum, Cercospora zeina, and Bipolaris
maydis, respectively. Yield losses of more than 10% can occur if these
pathogens are diagnosed inaccurately or managed ineffectively. Here, we
review recent advances in understanding the population biology and
management of the three pathogens, which are present in Africa and thrive
under similar environmental conditions during a single growing season. To
effectively manage these pathogens, there is an increasing adoption of
breeding for resistance at the small-scale level combined with cultural
practices. Fungicide usage in African cropping systems is limited due to high
costs and avoidance of chemical control. Currently, there is limited knowledge
available on the population biology and genetics of these pathogens in Africa.
The evolutionary potential of these pathogens to overcome host resistance has
not been fully established. There is a need to conduct large-scale sampling of
isolates to study their diversity and trace their migration patterns across
the continent.
