Introduction
Charcoal rot of soybean, caused by
Macrophomina phaseolina
(Tassi)Goidanich,isoneofthemostimportantsoilbornepathogens,
infecting over 500 plant species in more than 100 plant families
around the world (
Smith and Wyllie,1999
). Charcoal rot has been a
problem for soybean farmers in the United States for many years
causing signi
fi
cant yield losses with estimated losses of
8.54
10
5
tonneperyearfrom1974to1994innon-irrigated
fi
eldsin
the 16 southern states (
Wrather et al., 2009; Wrather et al., 2006
).
Symptoms of charcoal rot are also referred to as dry-weather
wilt or summer wilt, because it often occurs when plants are