THE Scottish potato harvesting has been progressing well in the recent fine weather, and is now more than half way through.

Crop yields this year look to be lower than average, mainly as a result of planting in the spring being delayed by about a fortnight, and the summer not being "growthy" enough to make up for that setback.

Both in Scotland and England, MET Office data shows that weather in June and July has been relatively dull and wet, but by no means the most extreme year. Scotland has had the fourth-wettest and fifth-dullest conditions in those two months since the year 2000.

Looking at the data a pattern of minimum sunshine levels required to maintain good yield potential seem to emerge.

For England, the two years of especially poor yields (2007 and 2012) correlate with years with fewer than 350 hours of sunshine in June and July.

For Scotland, only 2012 was an especially poor yielding year (with 210 hours of sunshine) - the threshold appears closer to 250 hours.

This year's figure of 253 hours of sunshine in Scotland is just above the threshold, although 2007 and 2015 had similar sunshine levels in Scotland but above-average yields in both cases.

Fortunately, while yields are slightly lower, the quality of the crop is relatively good because rain came at the right time in those critical months of June and July to avoid common scab issues - it's a skin blemish that is exacerbated by dry weather just as the young tubers are forming.

Inclement weather in many of the main European potato growing countries has depressed yields and is delaying harvesting, leading to predictions of rising prices.

The area planted may have increased in the main growing countries, but harvest losses may do more than wipe out the increases.

For instance, in Belgium growers are struggling to lift potatoes as the late summer drought turns into an autumn one. There has been some rain in the north and west of the country recently, but still not enough to really loosen soil and allow smooth harvest conditions. In the south of the country where a sizeable area of potatoes are grown there was only 5mm of rain at the end of September which did little but dampen the dust. It's much the same in the Netherlands, Germany and France. Only Poland looks set for a bumper harvest that is on target to see yields rise by more than 30 per cent. Unfortunately Poland cannot solve the western supply problems because of unsuitable varieties and phytosanitary problems.

Potatoes are a healthy component in a balanced diet that are fat free, an excellent source of fibre and supply 40 per cent of the UK population's Vitamin C intake. The humble spud is a great, nutritional option for low-income households and families facing tight budgets.

The Inca Indians first cultivated them in Peru around 200 B.C., but they had other uses for them in addition to consumption. They placed raw slices on broken bones to promote healing, and carried them around to prevent rheumatism.

Other folk remedies consist of washing your face with cool potato juice to treat facial blemishes. Frostbites and sunburn are treated by applying raw grated potato or potato juice onto the area.

Scottish scientist at the Dundee-based James Hutton Institute are investigating the possibility of extracting solanesol, a compound found in the leaves of potatoes as well as other solanaceous plants like tobacco, tomatoes, aubergine

and pepper plants . The chemical is already a key component in the manufacture of coenzyme Q10, which is used in beauty products to combat the appearance of ageing.

Solanesol can fairly be described as a "wonder" drug, and confirms that the Incas were onto something over two thousand years ago. It possesses antibacterial, antifungal, antiviral, anticancer, anti-inflammatory, and anti-ulcer activities. Solanesol derivatives also have anti-oxidant and anti-tumour activities and can be used for the treatment of cardiovascular disease, osteoporosis, acquired immune deficiency syndrome and wound healing.

There is growing speculation about the considerable potential for harvesting the potato leaves rather than "burning" them off - as is the current practice - and adding more value to the potato crop by extracting solanesol.

As growers wait for scientists to develop another income stream, they have to concentrate on finishing the harvest and marketing the crop.

While it looks like prices are set to rise, history reminds us that consumers respond by buying less.