General
The potato, native to South America, is one of the most cultivated vegetables in our gardens. It even takes its place in the rotation of our crops. It is rare that we do not eat this vegetable every day in different forms (plain, chips, mashed potatoes, etc.).
The first description dates from the 16th century. It was first introduced in Spain and in 1560 in Italy. Its spread in Europe dates from the 18th century. In France, the potato was the vegetable of the poor and animals in the 18th century. It was pernicious and caused leprosy. It was Parmentier, pharmacist at the Hôtel des Invalides, who, thanks to his works and publications (1772), rehabilitated its cultivation and finally got it going.
The potato belongs to the Solanaceae family in the genus SOLANUM and to the species TUBEROSUM. Its scientific name is therefore SOLANUM TUBEROSUM. belong to the same botanical family: pepper, eggplant, tobacco and tomato. The potato itself is a tuber; it is an underground tuber stem. This reserve organ is very rich in carbohydrates (starch).
Like all stems, potatoes also have eyes (they are in small depressions). They give rise to leafy stems that will bear white or purple flowers. Fertilization gives green spherical berries that contain many seeds. Not all varieties flower. Tuber formation is only possible if the following conditions are met: not too high soil temperature, good leaf surface, good sunlight and balanced nutrition. Mature tubers are sensitive to greening: they form solanine (toxic alkaloid) when exposed to light.
Classification and varieties
Potatoes are classified according to the earliness of harvest; very early, early, medium-late and late
a) Very early potatoes
- WHITE FIRST STEEL: white flesh, very sensitive to mildew
- Belle de FONT NL A Y: yellow flesh, good quality
b) Early and semi-early potatoes
- OSTARA: yellow flesh, sensitive to mildew, large size
- PRIMURA: low yield, quite sensitive to mildew
- ROSABELLE: high yield, red skin and yellow flesh
- SIRTEMA: low yield and very sensitive to mildew
- BEA: good performance
- CHARLOTTE: one of the best semi-houses
Let us also mention: ALEMARIA, AMINCA, AXILIA, CARINA, C1VA, CORINA, BORE, GLORIA, ISABELLE,…
Requirements
The potato adapts well to a mild and humid climate with a lot of sun. Growth is only effective from 10°C. The non-optimal temperature varies between +15 and +21°C. A lot of water is needed for tuber formation. Deep soil without excess moisture is favorable. For early crops, well-lit plots and lighter soils should be reserved. The potato occupies the third plane in the four-year rotation. Therefore, 500 kg of well-developed manure is applied to the area. This organic matter is supplemented with chemical inputs. The average amount of manure added to the soil is as follows: 3 kg of ammonium nitrate, 6 kg of superphosphate and 4 kg of potassium sulphate for soil preparation. In general, the pH should be between 5 and 6. Above this level, the potato develops the common scab disease in soil that is too calcareous.
Plant preparation
Buy new commercially available seedlings every year. They are selected and certified virus-free. The size of the first is 28/35 or 35/45. The larger your plant, the more small tubers you get. There are more or less 40 plants per kilo. After purchasing your seedlings, you need to prepare them for planting. They undergo a foretaste: expose them to light for a month and a half at a temperature of 10 ° C before planting. The result is a compact sprout, 2 to 3 cm long.
Planting
It is usually planted in grooves that are 50 to 60 cm apart and about 10 cm deep. In the row, the tubers are arranged every 35 cm. These distances apply to early crops. Direct the sprouts upwards, without breaking them. Earthing up can be done immediately after planting, which saves labor and protects the plants from the heat. This planting is carried out from March 15 to early April, depending on whether or not a perforated plastic cover is used.
Culture
HARVESTED PLANTATION:
- with plastic, March 15 after 90 days / April 1 after 75 days
- without plastic, April 1 after 90 days
Light weeding at the origin destroys weeds and maintains the soil water.
If this is not done at planting, there are two ridges, when the leaf is 15 and 30 cm high.
Harvest
The normal cultivation period is 90 days, depending of course on the climatic conditions and the quality of the soil. The early harvest is progressive. The first harvests are a delight for the amateur, while the following ones continue to gain weight and volume. When harvesting, one must be careful not to damage the tubers. Let them dry in the field or in an airy, dark room. One can hope to get 200 to 250 kg.
Defense of cultures
In general, early potatoes, harvested at the end of June, suffer less damage than late potatoes. However, antifungal spraying with MANEBE, MANCOZEBE, or ZINEBE will eliminate the risk of late blight.
There are varieties that are resistant or not very sensitive to virus diseases and scab.