Bacterial hollow stalk is caused by the same bacterium that causes bacterial black stalk, and the same environmental conditions favor both diseases. Hollow stalk often begins at the wound created at topping. (Photo: Kenneth Seebold, UK) 

The hollow stalk bacterium decays the pith (center of the stalk), resulting in a hollow stem. Infections that begin in the field will continue to develop when plants are hung in the barn. (Photo: Paul Bachi, UK)