Potatoes (Solanum tuberosum) are a useful crop that provide high yields of carbohydrate and protein from their tubers. The plant, which is sown in the spring, grows quickly and the tubers can be harvested throughout the summer and autumn months.

Potatoes were first domesticated in Peru and Chile and introduced to the British Isles around 1600AD, possibly from the wrecks of the Spanish Armada. Very quickly they became an important part of the diet. Initially they were grown in gardens and on smallholdings but it was not until the latter part of the eighteenth century that potatoes became popular as a field crop. Tubers were used for human consumption and for fattening pigs while the crop provided a good break in the cereal rotation.

Over the next century their popularity grew to such an extent that they became the staple diet of a large part of the population until the potato blight of the 1840s.The blight, caused by the fungus Phytopthera infestans, particularly affected Ireland where the population had become very dependent. The Irish potato famine which started in 1845 continued for two years and as many as 1 million people died of starvation with many more emigrating.

Today, potatoes remain an important staple in the diet but overall human dependency on the crop is much reduced. However, whilst potatoes are often incorrectly characterised as being a fattening food they are prone to the a build up of a toxic chemical called solanine if exposed to light. Solanine concentrates in the skin of the tuber and will be present at raised levels if the tubers have sprouted or turned green. To prevent this, potatoes should always be stored in dark cool conditions.

Most potatoes are planted in April and depending upon the variety, harvested through the summer and autumn months. Early maturing varieties which are harvested first are known as first earlies. Second earlies follow with the maincrop being last, typically in September. Around 80% of the crop is destined for human consumption either as whole potatoes or in some sort of processed form. The balance of the crop is used for seed production and for feeding to livestock. As potatoes are susceptible to viral diseases which are spread by aphids, seed potatoes are usually sourced from higher ground in the north of the country where aphids are uncommon.

Yields of potatoes have been increasing over the past three decades and typically now yield around 45 tonnes per hectare. As consumption has remained static, the increase in supply has lowered prices and the number of producers has declined. Around 4000 producers supply over 90% of the market. Financial returns are notoriously variable with a number of poor or indifferent years being offset by years of very high prices and good return. On arable farms, potatoes are a good break helping to reduce the weed and disease burden in the following arable crop. However, potatoes themselves are quite susceptible to pest and disease infection and are normally grown on a five year rotation.

Further reading for Potatoes - Production cycle >>

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