Environmental & other issues
Charcoal Stalk Rot
Description
Charcoal stalk rot develops under soil conditions that are hot and droughty for extended periods of time later in the season. Charcoal stalk rot shows the same symptoms of vascular shredding as Fusarium, but in this case, small, black fruiting structures form on the vascular bundles, giving the interior of the stalk a dark gray discoloration.
Photo credits
Sorghum Production Problems