While it is generally agreed that international production of many fruit and vegetables has already reached glut proportions, it is always something of a mystery to see relatively unusual sources still popping up on the retail shelves, writes David Shapley.

Certainly there can be mitigating circumstances. According to my sources the cold weather in Spain has reduced the raspberry crop, which probably accounts for the arrival of South African fruit at Marks & Spencer.

The 170g packs were making £2.99, but what was more interesting was that the variety was Driscoll Isabel, reflecting how quickly promising varieties can spread across the globe.

Another example, as buyers continue to re-programme to fill the hole left by the hurricanes which decimated Florida’s grapefruit crop, was evident in Morrisons - pink grapefruit from the Bahamas at £1.29 for a net of five (pictured above).

It is not the most likely area, although not new. I remember seeing samples several years ago when Florida was again trying to recover from a particularly bad bout of frost damage.

Less easy to fathom, when salad displays in general are overloaded with tomatoes of all shapes, sizes, varieties and accompanying mouth-watering descriptions, was the presence of 500g pre-packs of cherry tomatoes from Senegal at Tesco (pictured right).

Meanwhile, I have always been intrigued with the use of nets to pre-pack fruit. They turn up regularly on kiwifruit, and even apples, but their main devotees are the citrus family, where some highly sophisticated packs have been developed with labels and offers stitched in as an integral part of the presentation.

So at Marks & Spencer this week it was like turning back the clock when I came across a three-pack of Spanish navels at £1.39 (pictured below). There was a time when that was all you could buy - but it is still a good, and convenient, way to offer a compromise between loose fruit and something more substantial.

The medium is also being used to boost sales of shallots in Waitrose. The difference is that rather than containing loose bulbs, these are presented on a mini-string, following the example of onions. Like herbs in a pot, the appeal of produce as a decoration in the kitchen has been extended. I wonder what will be next.

Meanwhile, the battle continues unabated to get the message across that you are offering something extra, as well as either claiming to be better value, or quality.

Tesco has once again begun signalling up, on shelf barkers, the comparable prices of its competitors.

At Marks & Spencer things are more gentlemanly, although at the checkout, where it provides the dividers to separate customers’ purchases, they were being used to put another message across which is always in the public mind. “We lead all major food retailers in reducing pesticides.”