De Meerlander (Meerlander potatoes)
BGA De Meerlander is the tuber of the ‘Meerlander’ variety of Solanum tuberosum L. intended for human consumption. This variety arose by crossing the Beverlander and Record varieties and came to market in 1947. ‘De Meerlander’ was developed in the Harlemmermeer, and the name is a reference to this.
‘De Meerlander’ is an early-ripening variety.
‘De Meerlander’ tubers are of medium size with a regular round to roundish-oval somewhat flattened shape, being of a regular size. They have a roughish pale yellow skin, shallow eyes and pale yellow flesh.
For culinary purposes, ‘De Meerlander’ is a CD potato: it is floury and not dense, with only a slight tendency to change colour when boiled. The dimension of the potato when offered to consumers is 40-55 mm.
Owing to its high dry matter content, which is around 20 %, this potato has a floury texture, with a starch content of 7 (on a scale from 1 to 10). Its underwater weight is on average 380 g.
The taste of ‘de Meerlander’ potatoes is mild and velvety, somewhat dry but yet full-flavoured. They have a slightly salty aroma.
Other characteristics of ‘de Meerlander’
‘De Meerlander’ is a keeping potato that is resistant to potato wart disease physio 1 (D1) and the A virus. Its tubers are not very susceptible to attack by Phytophthora infestans or to internal damage. The foliage is robust and large-leaved and provides very good cover.
Specific steps in production that must take place in the defined geographical area
‘De Meerlander’ potatoes are grown from approved seed potatoes on suitable, well-drained plots of land in the Haarlemmermeer. They are planted in April or May. The planting distance between rows and between plants is 75 × (28-32) cm, as a result of which the harvested product generally measures 40-55 mm across. Fertiliser use is adapted to these factors, preference being given to the use of organic fertilisers, supplemented if need be by artificial fertilisers. The date of the harvest varies but usually falls in September. The potatoes are graded when harvested according to size and quality.
Concise definition of the geographical area
The geographical area in which ‘de Meerlander’ potatoes may be grown is confined to farmland on the Haarlemmermeer polder, which is surrounded by the Ringvaart canal. The geographical area is thus restricted to the area within the Ringvaart canal.
Link with the geographical area
‘De Meerlander’ potatoes were developed in 1936 in the Haarlemmermeer: the name is derived from the name of the area. The variety was first placed on the Dutch Varieties List in 1947, and since then the Haarlemmermeer has been the area where it is grown. Just over 150 years ago, a start was made on draining the Haarlemmermeer, which at the time covered an area of just over 18 000 ha. The ‘old sea clay’ which had lain below the fen and was exposed when the area was drained contains soil that is very different from the soils in other drained areas. The composition of the clay soil in the delimited area means that it is more fertile than other (sandy) soils. The clay soil is able to bind to the clay fraction (positive) ions of minerals that are dissolved in the groundwater. As a result, the minerals are not washed away with the groundwater but remain bound to the clay particles and in this way can be absorbed by the potato plants.
The Haarlemmermeer’s geographical location close to the coast (on average 15-20 km from the North Sea), where salt infiltration has given the groundwater a sea salt content that is higher on average than elsewhere, makes for a slightly saline growing medium which influences the taste of the potatoes and gives them their slightly salty aroma. The weather in the area is characterised by regular rainfall and winds from the sea and produces a growing climate for ‘de Meerlander’ potatoes that is conducive to the formation of tubers of a much better size range, with far less tuber defects than are found elsewhere. The compact structure of the clay soil means that no excrescences or other irregular shapes can form on the surface of ‘de Meerlander’ potatoes. They are worn away, as it were. The clay soil gives ‘de Meerlander’ potatoes a slightly less rough skin and a slightly yellower colour than potatoes grown in sandy soil. The old low-lime sea clay soil of the Haarlemmermeer, which has a < 16 μm inorganic particle content of 23 % and a fairly high pH (7,2), yield ‘de Meerlander’ potatoes that are flourier on average and that have a somewhat higher underwater weight than potatoes grown in sandy soils elsewhere in the Netherlands.
Potato-growing has long been associated with the Haarlemmermeer area, mainly because of the particular soil qualities mentioned above, the special qualitative and organoleptic characteristics of ‘de Meerlander’ potatoes and the growing techniques employed by the growers. Potato cultivation has therefore always been an important economic factor on this polder. From the late 1950s, more and more organisations became involved in selling ‘de Meerlander’ seed potatoes, so that eventually nearly 400 tonnes of seed potatoes were being sold in the Haarlemmermeer area for ‘de Meerlander’ potatoes. These potatoes were sold by merchants who were well known in those days. This variety has since always been produced in small quantities and plays an important role as a regional speciality. The mayor of Haarlemmermeer therefore also gave permission for the ‘De Meerlander Aardappel’ cooperative to use the municipality’s coat of arms with the aim of emphasising the origin of the ‘de Meerlander’ potato and clearly identifying it as an original Haarlemmermeer product.
Reference: The European Commission