Article by Lindy J. Rose and Karlien van Zyl
Department of Plant Pathology,
Stellenbosch University
T
he importance of maize
within the South African
context needs no introduction. Maize serves as a staple food for millions of SouAth Africans, with consumption levels in
certain areas as high as 500 grams
per person per day, and is the major feed grain. Its successful production is, however, under continuous pressure. Fusarium ear rot is an
important disease that can affect
the yield and quality of maize
grain. It is predominantly caused by
the fungus Fusarium verticillioides,
while other Fusarium species such
as F. subglutinans and F. proliferatum are also responsible for the
disease.
In South Africa, F. verticillioides is
the one of the main fungal contaminants of maize, and Fusarium
ear rot occurs wherever the crop is
grown. Hot dry weather conditions
promote the severity of the disease,
and high levels of infection have
been reported in the western Free
State, Northwest and Northern
Cape provinces. More importantly,
F. verticillioides also produces mycotoxins, which are poisonous substances produced by fungi, called
fumonisins. The ingestion of
fumonisin-contaminated grain has
been associated with serious illness
and immune suppression in humans and livestock. Fumonisins
have been associated with an elevated risk for oesophageal cancer
Figure 1: The possible infection pathways of Fusarium verticillioides to cause Fusarium ear rot of maize