This is a busy time of year for Scotland's soft fruit growers as they pick their crops.

The industry has changed dramatically compared to 20 years or so ago, when everything was picked by hand and mostly destined to be processed into jam or juice. Growers used to arrange for special buses to collect fruit pickers from the likes of Dundee and Fife, until machines started to take over. Sadly, about that time, the industry came under pressure from cheap imports from Eastern Europe and the area where fruit was grown declined dramatically.

Back in 1982, Scotland grew a massive 2,593 hectares (ha) of raspberries and 768ha of strawberries. Over the past 10 years the area of raspberries in Scotland has contracted from 519ha to 188ha, strawberries are down from 678ha to 141ha in the same period and blackcurrants down from 405ha to 295ha.

That may appear depressing reading until you realise that the value of Scotland's soft fruit production has actually increased by £56 million (152 per cent) to an estimated £93m in the same period. The increase in value of the crop is mostly down to better yields and better prices as a result of selling to retailers rather than processors.

Over the past decade the value of Scottish strawberries has increased by £46m (190 per cent). This was mostly due to a 14,000t increase in production, along with an increase in average prices of £400/t. The value of raspberries increased slightly by £1.4m over the same period, with estimated production at its lowest level in the last decade as a result of poor yields in 2013 and a reduced area, but with an increase in price.

All Scottish strawberries are hand-picked, with around 90 per cent going to the fresh market and the rest to processing. At one time 80 per cent of the raspberry crop was made into jam, but nowadays about 85-90 per cent of raspberries end up being sold as fresh fruit after being hand-picked, with the balance going for processing.

While blueberries, gooseberries and currants are hand-picked for the fresh market, almost all blackcurrants are mechanically harvested and processed into juice.

The big change in Scotland has been the development of growing fruit in polytunnels which don't come cheap. A hectare of polytunnel costs about £25,000 and should produce between 25 and 30 tonnes of strawberries in a season. The price a grower receives for a tonne of strawberries from the supermarkets is a hefty £3,000, although about half of that is spent on picking, packaging and transport.

While the UK market for soft fruit has grown rapidly over the last decade, Scottish growers have to compete with their counterparts south of the border for market share. The annual value of crop for the fresh market is very dependent on demand and how the crop develops to meet it.

Prices tend to be forced down in those years when the Scottish crop overlaps more with England's. Unusually that doesn't seem to have happened to strawberries this year, despite a three-week overlap, and prices are around a third higher than last year. Unfortunately the same cannot be said for the price of Scottish raspberries which have been depressed by a very big English crop, although things should improve for Scottish growers now that English supplies are tailing off.

Although buses no longer collect fruit pickers, the industry still employs large numbers of seasonal workers. Most of them come from Eastern Europe and live in static caravans provided by the growers. That allows flexibility of working hours for the pickers.

Sometimes fruit has to be picked very early in the morning to supply orders from supermarkets. Then again, it may become too hot during the day to work, and picking may have to take place in early morning or evening, so workers need to live on the farm.

I remember going to a grower about 25 years ago to interview him for an article I was writing on the impact of cheap imports from Eastern Europe. I arrived at the farmhouse to be told by his wife that he was in one of the fields supervising the pickers, and given directions to find him.

While parking my car I decided to take a photograph of the pickers to illustrate the article . As I stood there in my suit with camera in hand, the workforce literally disappeared in front of my eyes, They thought I was from social security.