Potato (Solanum tuberosum)

Hlízy
 

The potatoes can be breed by vegetative and generative way. There the potatoes are breed only by vegetative way (by the tubers) in our country and in almost all the countries even if it demands a large number of seed potatoes, and higher planting storage costs. The generative reproduction is used at breeding.

Meaning and content

The potato tuber contains high amount of water. Other matters containing in the tuber are subject to meaningful variability which depends on the species of the potato, and on the growth environment. The potatoes contain 23 – 24 % of dry matter on average with minimal value about 13 % and maximal value about 38 %. The rest is formed by water. The content of starch is from 8 to 29,5 % (usually but 13 – 24 %), whereas the early species and very early species have the lowest content of starch. The potatoes contain more other polysaccharides except the starch – fibrous material, hemicellulose, pectine, hexose, and pentose. There is the content of monosaccharides and oligosaccharides is small in the healthy and mature tubers: sucrose 0,10 – 0,40 %, glucose 0,05 – 0,20 % a fructose 0,10 – 0, 40 % at the original matter. The nitrogenous matters are proteins, amino-acids, amides, and inorganic compounds. The proteins form 1/3 – 1/2. The nitrates are significant content of nitrogenous complex. By the Food Act, N. 110/1997 (Collection of Law), the highest acceptable amount of nitrates is 500 mg/kg of original matter for early potatoes (to 15. 7.) and it is only 300 mg/kg after 15. 7. There is mixture of glycoalkaloids in the potato tubers, they are expressed as solanine. The solanine excites the mucous membrane of gastro-intestinal tract, and it takes bad effect on nervous system. The effects of solanine are destroyed by heat correction, the ruminants are more resistant – the crude potatoes are used, the potatoes are boiled or smoked for other animals.

 Useful ways of potatoes
 

The industrial potatoes are important base material mainly for starch production. There the production of ethanol dropped to minimum in the Czech Republic because of easier, cheaper and more ecological production of cereals, maize, and molasses displace it.

There the potatoes for livestock feeding are not grown in the Czech Republic at present. There only the residues of food, seed, and industrial potatoes, eventually over-harvest are used for these purposes.

Grower requirements

It is possible to grow the potatoes at all the growing regions in the Czech Republic, the potato growing region is typical for potato production, there are annual precipitation 650 – 800 mm, and there the potatoes amount to the stationary yields at the potato growing region. The potatoes are improving and weed crops at the crop rotation, the are not preceding crop-intensive. The potatoes are placed between two cereals at the crop rotation, they are fertilized by manures. It is not good to grow potatoes after potatoes by the reason of higher appearance of diseases and pests. There should be minimally three-year intervals for food and industrial potatoes at the crop rotation. The light and middle heavy soils with good pervious sediment, with lightly acid soil reaction pH 5,5 to 6,5, with good level of old soil power (the areas which are fertilized regularly by manures), are optimal for potato cropping. Very wet and very light soils are not suitable for potato cropping. The stony areas are not suitable for mechanized harvest, there tuber injuries and cranky mechanizations happen during the harvest. The potatoes are moisture demanding crop. Low temperature resistance is small, the potatoes are frozen when the temperatures from -1,5 to -2°C  take longer.