Famine bomb

.Famine bombs were among the weapons deployed by the Daleks ahead of a main invasion force to "soften up" their enemies. Upon exploding, the bombs released gases which killed most edible plants and animals on the planet the Daleks wished to invade, though it could not affect root vegetables. If the Daleks later wished to keep some inhabitants alive and well-fed after the invasion was complete, so as to make them into slaves or Robomen, they would instead feed them through the nouromatic machines. (NOTVALID: Inside a Skaro Saucer)