If it is caused by mold, the corn should not be eaten because it may affect the nutritional value of the corn, and after eating it, it may cause adverse health effects.
If the black powder fungus appears when the corn is not fully ripe, then it is edible. The black powder fungus of corn is an edible fungus that has the effect of benefiting the qi and nourishing the yin, replenishing the qi and calming the spirit, and is said to be effective for those who suffer from insomnia and excessive dreaming. But in the case of not being able to determine what kind of substance is causing it, it is still recommended not to consume it in order to avoid food safety problems.