I know they seem to be pro-leave - I just don't full understand why. They should be the areas least affected by immigration, and most benefitting from financial aid from Europe.
It makes some sort of sense to me.
First, before we entered the EEC our farmers were significantly insulated from external competition by tariff barriers and in some cases central buying. Replacing that with EU subsidies is a poor substitute for fiercely independent people - nobody wants to be seen to be "on benefits".
Second, there's the overseas competition itself. A friend of mine is a farm labourer on a tiny farm in the Home Counties, and he has to know a lot about the weather across the EU so he can get his crops to market at the right time before they are swamped with imported stuff. It adds another layer of complexity to everything.
Third, rural communities are often very suspicious of outsiders. That includes, for example, Londoners buying up cottages as weekend retreats. When you're talking immigration it isn't just foreigners that count - it is every outsider, and the two form part of the same category.
Fourth, such immigration as there is is very very noticeable. On one occasion I remember hearing of from a local - about 20 years ago six illegal immigrants had been dumped at a bus stop in the small hours of a winter morning in a Cotswold village. In a city you wouldn't even notice - in the country it is still a topic of conversation 20 years on for 20 miles around.
Fifth, all Conservative
The absolute worst is American saying "period", all the time.
Early in my programming career I was subjected to a dreadful American video course in COBOL in which the line "Gee, I guess I missed a period" caused some uproar. The young lady meant, of course, that she had omitted a full stop.