Taking unwashed machines from one farm to another risks spreading disease
Moving farm machinery from one county to another, from one farm to another farm, or even from one field to the next field, has the real possibility of transferring seeds and diseases that can affect both plants and animals. How easy it is to finish one job, pack the harvester or spreader for transport, and drive off down the road to the next farm - or load the machine onto a truck or trailer and move it hundreds of miles to the next farm which needs the service.
