The storage silo, which was used during harvest time, had an exit hole at the bottom where grain could pour out of and onto a chain conveyor belt.
On 1 August 2014 this exit hole became blocked, as it frequently did. Fox entered the vessel in an attempt to clear the build-up from inside while it still contained a large amount of grain.
Fox managed to unclog the exit hole but, as the grain started to flow again, he became submerged in it and was asphyxiated.
A Health and Safety Executive (HSE) investigation found the system of work for clearing blockages in the grain bin was inherently and obviously unsafe.
Seamore Farming was fined £45,000 at Jedburgh Sheriff Court after it pleaded guilty to breaching Section 3(1) of the Health and Safety at Work Act.
After sentencing HSE inspector Allison Aitken said: "Farmers should ensure that they have a safe system of work in place for clearing blockages in grain silos which avoids the need for anyone to enter inside them. This can be easily achieved, where necessary, by making some minor modifications to working practices to enable the task to be completed safely from outside the grain silo."