Sporulation occurs in?

Stationary phase: After a varying period of exponential growth cell division stops due to depletion of nutrients and accumulation of toxic products the number of progeny cells formed is just enough to replace the number of cells formed is just enough to replace the number of cells that die. The ble count remains stationary as an equilibrium exists between the dying and the newly formed cells Ref: Ananthanarayan & paniker's Textbook of Microbiology 9th edition pg no 22