Can vegetables, fruit, and the kaiser too poster analysis

The poster makes a play on words as part of the home front efforts in World War I. It encourages citizens to grow and preserve their own food as part of the war effort. The pun on "can" as meaning to fire from a job or discard in a trash can relates the food canning to the drive to remove Kaiser Wilhelm of Germany. The small print offers a book on how to preserve foods.

All of them are man made