Potatoes are an annual plant in the nightshade family, the genus Nightshade. It is propagated vegetatively and by seeds. Vegetative propagation is used in production. Growing potatoes from seeds is practiced only in breeding work.

The potato tuber is the thickened end of an underground shoot (stolon). It serves as a repository of nutrients that are fully utilized during germination.
Tubers contain 75% water, 20 – 25% dry matter, including 17 – 20% starch, 1.5 – 3% protein, 1% fiber, 0.2 – 0.3% fat, 0.3% sugar and about 1% ash.

By its botanical origin, potatoes are a plant of a moderately cool climate with average annual temperatures between +6° and 10°C and relatively high air humidity. Potatoes begin to grow when the soil temperature reaches +8°C, at temperatures above +30°C, potato plants are strongly depressed.

At high temperatures (above +25°C) tuber formation slows down, and at +29 – 30°C it stops. When the air temperature is above +42°C, the tops stop growing, since the plant consumes more assimilation products for respiration than they are accumulated by the leaves in the process of photosynthesis.

The sum of active temperatures during the growing season for early and mid-early varieties is 1000-1400°C, for late-maturing varieties – 1400-1600°C.

With the accumulation of excessive temperatures, “overgrowth” begins – the tubers of the new crop form stolons, on which, in turn, new tubers are set.

The duration of the vegetation period varies quite a lot for varieties of different ripening periods: from 45-50 days for ultra-early varieties to 110-120 days for late-ripening varieties. Accordingly, the variety is selected depending on the duration of the frost-free period in the region of cultivation.

Especially suitable for the cultivation of potatoes are sandy loam and light loamy soils, which remain loose during the growing season, do not float after rains, have a neutral or slightly acidic reaction, and contain at least 2% humus. In heavy soils, it is necessary to apply large doses of organic fertilizers. The thickness of the arable layer for potatoes should be at least 27 – 30 cm.

Potatoes are not too demanding in terms of soil conditions. It grows best and gives a high yield of good quality on sufficiently aerated, loose, easily warmed soil, but with appropriate agricultural techniques, it can be grown on almost any soil that has a slightly acidic or neutral soil reaction. The optimal Ph value is 5.5 – 5.8 (slightly acidic soil). Potatoes are insensitive to acidity, and need liming only on medium- and strongly acidic soils.

The moisture requirement of potatoes, compared to other cultivated plants, is average. The transpiration coefficient (the amount of water required to produce 1 kg of dry weight) is about 550 l/kg. For comparison, this indicator is 350 for sugar beet, 450 for wheat and barley, 550 for sunflower, 650 for rapeseed, peas, and 700 l/kg of dry weight for alfalfa.

For the production of 100 centners/ha of dry matter (500 centners of tubers/ha), about 3 thousand tons of water (300… 400 mm EFFECTIVE precipitation). The amount of water that falls in the form of rain is divided into:

• surface runoff.
• evaporation
• moisture available to plants that has seeped into the lower layers of the soil.

As a result, the plant receives about 30% of the total water precipitation during the growing season.

The soil moisture under the potatoes should be about 80% of the total field moisture capacity. To the eye, this state of the soil looks like “dirt between the rows”.

Potatoes need 5 … 6 mm of water from the soil moisture reserve. After a period of optimal water supply, which promotes active leaf growth, even slight disturbances in the water regime lead to a decrease in yield. Heavy rainfall after a long dry period causes tuber overgrowth (secondary growth). Against the background of long-term stagnation of water with excessive moisture, “suffocation” of tubers occurs, characterized by swelling of lentils.
In addition to meeting the requirements of the crop for soil, humidity and temperature, it is necessary to remove competitors from the field in the fight for nutrients – weeds and pests that feed on potatoes. Protection of potatoes from harmful objects with the use of products produced by Agro Expert Group will be presented in subsequent publications.

It is recommended to dig potatoes in the temperature range from +3-4°C to +22-24°C. At low temperatures, the danger of mechanical damage increases and the traces of bruises appear stronger.
In conclusion, I would like to remind you that miracles do not happen. And only strict adherence to agrotechnical recommendations allows you to grow potatoes in large quantities and excellent quality, which will be well stored and sold at a high price.

Author: Svetlana Zhupikova, Potato
Manager,
Agro Expert Group LLC.

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