In France, they talk about ‘terroir’, the unique interplay of climate, soil, tradition, and human touch that gives a region’s products its very distinctive identity.

But as Perthshire’s famed raspberries prove, that ‘terroir’ is never quite set in stone, as the interplay of nature’s complexity and man’s demands can lead to significant changes and challenges to those who make their living from these delicate soft fruit.

Along with Fife and Angus, the east of Scotland provides a fertile mix of conditions for raising fruit. Loamy soils that warm up quickly and enjoy good drainage, coupled with long summer daylight hours, a climate that’s drier than the west coast, along with relatively moderate temperatures – all played a role in making the growing of raspberries, strawberries and blackcurrants a commercial proposition.

Local solicitor James (or JM) Hodge, was one of the first to see the commercial potential of the raspberries in and around Blairgowrie. In the early decades of the twentieth century he persuaded locals to rent land purely for growing raspberries on a much larger scale.

At the same time, his astute marketing eye did a lot to develop outlets for the berries, principally as jam pulp, connecting up with jam ‘barons’ such as Sir William Hartley.

As the size of the crops expanded during inter-war years, the number of pickers grew too, ‘tinkers fae aa the different pairts an folk fae the toons’ as one picker recalls.

Special accommodation was built for them in Essendy, about 3½ miles from Blairgowrie, nicknamed the ‘Tin City’ after its tin roofs. Picking was paid at the rate of ½p per pound and it was claimed that good pickers could earn up to 15p per day.

Fast forward many decades and the pickers are more likely to be coming from eastern Europe, and be working inside the poly-tunnels that have spread so dramatically across the landscape – extending the growing season and protecting the crops from damage.

The widespread adoption of tunnels means production now runs from late May to late October, while the other major difference is that raspberries these days are more likely to be picked for supply as fresh fruit to the supermarkets.

Even still, raspberries are facing the dual threat of disease and commercial pressures that’s seen their numbers tumble from 2593 hectares of cultivation in 1982, down to under 400 hectares in 2012, with only half that number grown in the open field.

The yield-improving cultivars developed by the Scottish Crop Research Institute (now the James Hutton Institute) at Invergowrie in the 1960s, 70s and 80s have shown to be susceptible to raspberry root rot, and consequently breeders are looking to develop new varieties offering not just disease resistance, but the size, colour, shape, yield and shelf life demanded by the supermarkets.

With such influences there’s always the fear that taste gets squeezed out of the equation, something the researchers resist manfully. Nikki Jennings, raspberry breeder with Mylnefield Research Services, a commmercial affiliation of the James Hutton Institute, identifies Glen Fyne in particular as a berry which grows really well under a polytunnel. More importantly, it has ‘a fantastic flavour, way better than Glen Ample.’

Coupling decades of experience and groundbreaking techniques such as molecular marking, Scottish scientists remain at the forefront of research and development not just in raspberries, but a range of other fruits too. For even as the colour fades a little from the raspberry market, canny local berry farmers are grabbing opportunities to diversify their growing skills, with gooseberries, blueberries and even cherries now finding a home in the berry fields of Blairgowrie and Strathmore. Perthshire’s terroir still has rich pickings to offer.