It takes but a shade over two hours by what used to be called the Great Western Railway to journey from Paddington to Exeter, in the heart of Devon. There is also the alternative – and some would say prettier – former Southern Railway route from Waterloo, which is a little longer.

However, neither, it seems, are about to be travelled by Defra Secretary Hilary Benn, who has declined an invitation from Devon NFU chairman Anthony Rew to pop down and get his boots dirty while talking to farmers whose lives are falling apart as a result of TB.

It matters not that TB is threatening to do more damage to livestock farming than foot-and-mouth: Mr Benn – the man who is supposed to be in charge of Government agriculture policy – won't be heading west.

Well, obviously, he has many other engagements to occupy his schedule. For instance, last week, according to Defra's website, he was in Kenya to attend the Governing Council of the United Nations Environmental Programme in Nairobi.

And he didn't go empty-handed, either, announcing the distribution of £8 million of Government (ie, taxpayers') boodle for wildlife projects across the developing world, including schemes for the conservation of chameleons in Madagascar and the restoration of habitats in small Pacific islands.

To keep his fans informed of his progress, Mr Benn even kept a diary on the website. Readers will doubtless be left overawed as he relates how "the pilot made a tight turn so we could get a good view of the hippos and pink flamingos before putting down on a narrow grass airstrip", and sympathise as he relates: "We got only four and a half hours' sleep on the plane to Nairobi."

British farmers who might wonder just what their Secretary of State is doing on such a jaunt will, however, be relieved to learn there was at least a horticultural element: a visit to a rose-growing company near Lake Naivasha.

Mr Benn even explains – as though he were doing it all for a Blue Peter audience – the elements of bio-control the growers use ("Basically, it's getting good bugs to eat bad bugs") and eulogises reed-bed technology ("Water turns from dirty brown to sparkling clear, and just to show his confidence in the system, the energetic farm manager knelt down and drank the clean water! We declined to follow his example but it was still very impressive").

Indeed, he found the entire visit quite an experience: "Just 48 hours pass between snipping the stems in Kenya and putting them on the shelves in the UK. It provides jobs, export income and brings smiles to our faces as we buy beautiful roses."

British farmers will be mightily impressed that Mr Benn has decided to travel quite so far to learn about reed-bed technology when he could have seen it in operation in any number of sites here. I am equally confident they will be thrilled to learn he is taking quite such an interest in horticulture, even though it's a rose-growing enterprise on the shores of distant Lake Naivasha.

And then I'm sure they will want to know when, after a week in which he trotted out the same old platitudes again to the NFU conference, he's going to remember he no longer works at the Department for International Development.

Not willing to take no for an answer, South West farmers are issuing a fresh invitation to Mr Benn to come to the region and talk about what he is – or isn't – doing to control TB. This time the request is coming from Somerset dairy farmer Derek Mead, who is offering his Sedgemoor Auction Centre as the venue for a meet-the-Minister event.

If Mr Benn needs further encouragement, two years ago Derek installed reed-bed filtration at another of his sites, just up the M5 at Puxton Park, and would be delighted to show him round – and probably kneel down and drink the clean water as well.

And just across the road from the auction centre is a market garden where Mr Benn could also inspect a horticultural operation – though one which provides British consumers with home-grown food rather than expensive imported roses.

But despite nearby Curry Moor having the semblance of a lake, thanks to the floods, hippos and pink flamingos there are, alas, none. Doubtless the location will prove just a tad too low on the exotic scale to tempt Mr Benn down.