By the mid-1980s combine harvesters were well developed.
However, the next 25 years would see technology become ever more advanced.
In particular the threshing system changed as rotary and hybrid combines established themselves in the market.
Computerisation transformed the driver's options, offering automatic steering, electronic monitoring and office management tools integral with the machine.
This programme shows these developments by looking in detail at 23 key models at work in the UK in 2009.