Seed potato production in England

The potato production in England consists of two specialized branches, namely, the production of seed potatoes and the production of table potatoes. The seed potato areas are usually restricted to those localities where temperature, rainfall, and soil conditions are favourable for the growing of potatoes of high quality, and free from disease.

The traditional areas of seed production are in the upland regions of England. It is widely known that this is because of the greatly reduced risk of virus and other diseases.

In upland areas, planting must be done at such a time so that young plants are not damaged by late frost. If soil conditions are dry, this may be any time after the end of March, but in rainy years planting may be done in May.

The experiments show that the best depth of planting potatoes in order to secure the highest yields is about 4 inches. This depth of planting usually gives higher yields than shallower or deeper planting.

In order that the tubers be of the proper seed-size, they are planted between 6 and 9 inches apart in rows 28 inches apart.

The optimum time for burning off¹ is usually the third week of July. Thus there is a fifteen or sixteen week growing period for the seed crop.

The potato crop removes large amount of nutrients from the soil especially potash. The potato crop of 400 bushels² removes 140 pounds of nitrogen, 30 pounds of phosphorus, 200 pounds of potassium, and 60 pounds of calcium from the soil.

The experiment to determine the best time to harvest seed crops of early varieties was conducted at the Rosewarne experimental station. There varieties Home Guard, Craigs Royal and Ulster Sceptre were harvested on four dates between early August and early November. Higher yields have been obtained from seed harvested in either August or September.

Weather conditions are very important in determining time of harvesting potatoes. It is desirable to lift tubers during the dry weather. In this case the keeping quality³ will be high. Potato tubers keep better if they are allowed to remain on the ground after digging for 1 or 2 hours.

Varieties vary considerably in their yield when kept at different temperatures. Home Guard, for example, is higher yielding when kept at 7.2°C, Craigs Royal can successfully be kept at 10°C, while Ulster Sceptre is low yielding when the storage temperature is 12.8°C but doubles its yield at 6.7°C. However, with most commonly grown early varieties the number tubers per plant is reduced at between 10 and 15°C temperatures but the weight of individual tubers increases. Although it is desirable to produce a crop of maximum size potatoes, it is often more economic to produce a higher yield of smaller tubers.

Proper temperatures can be maintained by automatic control of ventilation when the storage temperature increases.

With the use of automatic planting machines it is important at present that storage conditions provide proper number and length of sprouts per tuber. Sprouts should not be more than 1.5 inches long or they may prevent the tubers from moving through the machine. Multi-sprouted tubers are better because some of the sprouts may be damaged mechanically. To use the automatic planting machines successfully one should grade the seed tubers carefully before planting.

Notes and Commentary

¹ burning off – відмирання гички

² bushel – 36, 3 літра

³ keeping quality – якість при зберіганні