Drones may replace tractors for spraying

Japanese farmers do 90% of their crop spraying with unmanned helicopters, leading the march of the drones in world agriculture.

Drones are unmanned aerial vehicles — an industry that will have an $82bn economic impact and employ 100,000 by 2025, predicts the Association for Unmanned Vehicle Systems International (AUVSI), a non-profit group that advocates use of drones.

The history of drones begins as early as World War I, but it wasn’t until the 1970s that western militaries began to look for new ways to keep their human pilots from harm.