|
Charcoal
Rot
|
|
Charcoal rot (Macrophomina phaseolina)
can become widespread under hot, dry conditions. The disease usually
appears during pod-fill to maturity, with affected plants dying prematurely.
Crops under severe moisture stress are particularly susceptible. When plants
start to wilt and die, no external lesion or discoloration is visible on the
stem. However, if the bark is peeled away, the normally white to light-green,
inner stem will exhibit an orange-brown discoloration. Once
the plant has died, the external surface of the lower stem and taproot
eventually darken to a charcoal color. If affected stems are split lengthwise,
minute black fungal bodies (sclerotia) can be seen. Sclerotia can survive in the
soil for many years. They can also survive in crop trash, and are also seed
borne. To control the disease, irrigate regularly, and rotate crops.
|
|
|
Resources
|
|
|
