Show Us Your Invention - the celery push-knife

On First Up, we like to find out what sort of things New Zealanders have created in a segment called 'Show Us Your Invention'. In Pukekohe we found celery farmer David Clarke who, 20 years ago, traveled to the US and discovered a tool that would change his family's business forever. The Clarke family have been growing veges for more than half a century so David decided to make a similar one himself and use it to harvest celery. He calls it a 'push knife' and it's been so efficient that's it's resulted in two weeks worth of work being reduced to just one day.