WHEN AND HOW TO PLANT POTATO (on an example of Central Asia). What are tubers?

The potato demands well processed soft soil. At spring planting it is better to place after root crops, cucurbitaceous cultures, late-ripening cabbage, and at summer planting - after cropping of early vegetables, vegetable peas. For accelerate maturing of a potato and to get the big crop, tubers approximately one month prior to planting are sprouted. For this purpose tubers in weight 60-80g are selected and scattered them on a floor in light heat (12 - 15°С) premise.
Up to planting time on tubers short fragile potato sprouts are emerged on red - or blue-violet colour.
For obtain an early potato, tubers are sowed in the end of February - the beginning of March, depending on area.
A late potato is planted in June.
In southern areas of the meadow-bog soils, slowly drying out in the spring, tubers can be sowed as overwintering plant - in November-December. Delay with planting brings to decrease in productivity of a potato crop.
Planting distances are: 70cm between rows and 20-25cm between plants in rows. Norm of planting is - 25-35kg per 100м2 depending on the size of a tuber. Depth of planting of a potato in February-March - 6-8cm, in June - 12-16cm, towards the winter - 18-20cm (in the spring topsoil on overwintering potato crop was reduced to 8-10cm). In places planting, hollows are done. In everyone hollow put two or three handfuls of compost. Fertilizer is mixed with soil and tubers are put in the hollows.
Then the hollows covered with earth, carried furrow irrigation and mulching with humus, a film, and when summer planting sprinkled with straw, dry ground. 
With the shortage of seed material, tubers can be cut into pieces, so for each of them had two or three buds. At summer planting tubers can not cut on parts. The most common early, middle and middle-early potato varieties:
             - Priekule early,
- Sedov,
- Berlichingen, 
- Lorch, 
- Falenskiy.
Potato varieties recommended for planting in the spring: 
- Priekule early 
- Sedov,
- Falenskiy,
- Zarafshan
- Ural early,
- Belarus early,
- Berlichingen,
- Lorch.
For summer planting all varieties (except middle) are suitable.
Middle- and especially late potato varieties can not be used for spring planting.
 They do not have time to form a crop before the summer heat. 
Priekule early - high-yielding, white potatoes, starch - about 15%. Plants are resistant to cancer, but can sick with macrosporose. 
Sedov - early, high-yielding, resistant to degeneration, is also suitable for late and summer plantings. Tubers are round, large, white, good taste, their starch is low.
 Tubers are stored well. 
Berlichingen - sort of middle potato, fruitful, resistant to cancer and is quite resistant to scab, degeneration. Fresh tubers are suitable for planting. Tubers are red, oval, delicious, starchy is average. Tubers are stored well. 
Lorch - sort of middle potato, high yielding, zoned in all Central Asia republics. Tubers are large, round, oval, white, starchy, delicious. 
Falenskiy is middle-early, fruitful sort. Tubers are oblong-oval, white, average starchy, good taste. Tubers are rather good stored.