If you really want a laugh – we could all do with one – check the weather on Sunday, July 15, St Swithin’s Day. If it rains then, legend has it, it will rain for the next 40 days.

That’s a threat? After it has rained for the past 40 days or at least most of them? And on a few more since the end of March. Looking at rotting crops, unhealthy livestock, mud, flood and quite possibly pestilence and a plague of frogs, this must be the worst summer most of us can remember, certainly since 1985.

Crops rotting in the field is no exaggeration. They include broccoli, cauliflower, cabbages and potatoes. Only the large percentage of strawberry crops now grown in polytunnels has avoided the worst of a soft-fruit disaster.

As reported last week, sheep and cattle are suffering illnesses and infections caused by being permanently wet, standing in water and trying to live and grow on grass that is about 99.9 per cent water.

Regardless of St Swithin, one of many hit-or-miss old wives’ weather tales that we all trot out occasionally, the Met Office and weather specialists forecast that this wet and troubled weather will continue. The wettest, coldest, least-sun June in at least the past 100 years, possibly 300 – a month that was also part of the wettest April-to-June period on record – is being followed by what could be the wettest, dullest July.

Happy days, and the way we’re coping with it makes us proud to be British – agricultural shows, the Silverstone grand prix, music festivals and many local “if wet, in village hall” events, have been held in mud and rain.

No doubt the Olympics will also go ahead, even with global weather apparently static with Britain caught in the wet blockage and the US, for example, suffering from heatwaves. Chance would be a fine thing.

Some farmers have had more to occupy their minds than the weather. Unfortunately, the diversions have not been good news. Dairy farmers have been told milk prices are being reduced and pig farmers learned last week that the pig processing business Halls of Broxburn, now owned by Dutch company Vion, will probably close.

That closure is, of course, even worse news for the 1,700 employees and the town. But farmers have to take a necessarily blinkered view of how closure of a factory that slaughters and processes about 8,000 pigs a week will affect them.

The few pig farmers still in business, that is. Once numbered in thousands, when a big herd was 50 breeding sows, there are now only a few hundred pig farmers in Scotland, most of them in the north-east.

The biggest have several thousand breeding sows and by no means all rely on the Broxburn factory, where the handling system has become outdated and costs too high to compete with huge, modern factories in Europe dealing with up to 60,000 pigs a week.

It is also true that Scotland, and the north of England, have what the trade calls too much processing capacity. That is, not enough sheep, cattle and pigs are produced to keep production lines running at the rate needed to keep costs per carcase profitable. Vion claims it is losing £79,000 a day keeping Broxburn open.

Two big meat plants have already closed this year in Scotland – on Orkney and in the north-east – and the former role model for profitable meat processing, ANM, reported big losses. Anyone depressed about farming and thinking of investing in a slaughterhouse or meat processing at present would be well advised to think again.

The number of dairy farmers has also declined steadily over the past 30 years. There are now barely 1,000 in Scotland and few of those are in the Borders. Those that there are have large herds, well managed and high yielding.

The problem they face is cut-throat tactics from supermarkets squeezing milk processors who, in turn, have all announced in the past few days that ex-farm milk prices will be reduced by up to 2p a litre.

We have been here before, several times, since the abolition of the milk marketing boards with their statutory powers to buy all milk and fix prices in 1994. In the “free’’ market, prices have gone up and down, and with every down a few more dairy farmers decide to quit while those who stick with it increase herd size and try to extract more milk from each 

You would think that eventually there would be equilibrium, that public demand for milk would be met by just the right amount being produced. But so many other factors are involved – demand for cheese and butter, yoghurt and cream, demand for skimmed and semi-skimmed milk rather than whole milk – and the gradual takeover of the British market by continental companies – that there is no equilibrium.

There are still price cuts and fury, as with this week’s protest meetings by farmers, and the re-appearance of David Handley’s Farmers For Action group alongside the farmers’ unions.

As has been suggested, the one tactic that might embarrass the supermarkets would be for farmers to withhold supplies and pour their milk down drains. It’s one more indictment of supermarkets that that should even be considered in 2012. And would shoppers buying cheap milk care?