Potatoes in global agriculture: forage and industrial aspects

Fodder and industrial value of potato

Potato is not only a food crop, but also a highly efficient fodder crop. In terms of organic matter digestibility, it shares the top spot with fodder root crops. Using tubers in the diet of livestock animals allows for high productivity indicators with relatively low feed costs.

• Share of the global harvest for livestock feed — about 34%
• Digestibility of organic matter — 83–97%
• Nutritional value of 100 kg of raw tubers — 29.5 feed units
• Nutritional value of 100 kg of haulm silage — 8.5 feed units
• Weight gain of pigs per 1 ton of potatoes — 50–60 kg
• Milk yield of cows per 1 ton of potatoes — 280–300 kg

In addition to fodder purposes, potato is in demand as industrial raw material. About 4% of the global volume is processed into starch, alcohol, glucose, dextrin, and molasses. Starch remains an indispensable component in food, textile, and paper production.

Production geography and yield potential

Potato is cultivated in 130 countries worldwide, with plantings reaching as far as 71° N and 4° S, including mountainous regions. The global area under the crop is 18–25 million hectares, of which 8.4 million hectares are concentrated in Europe, about 1.2 million hectares in Asia, and about 0.3 million hectares in Africa. In the USA, 0.5 million hectares are occupied by the crop, with an annual harvest of more than 13 million tons and a yield of about 250 c/ha.

CIS countries hold the first place in the world in terms of planting area — about 8.7 million hectares, of which 3.3 million hectares are in Russia (including 1.4 million hectares in the Non-Chernozem region). Global potato production is shifting to Asia, Africa, and Latin America, where gross harvest grew from 80 million tons in 1990 to a record 161.5 million tons in 2005. More than 40% of the global volume is now grown in China, Russia, and India.

Countries	Production in 2004, t	Share in 2004, %	Production in 2005, t	Share in 2005, %
China	70 036 279.00	21	73 036 500.00	23
Russia	35 914 240.00	11	37 461 488.00	12
India	25 000 000.00	8	25 000 000.00	8
Ukraine	20 754 800.00	6	19 462 000.00	6
USA	20 685 670.00	6	19 151 080.00	6
Germany	13 044 000.00	4	11 624 000.00	4
Poland	13 998 654.00	4	11 009 392.00	3
Belarus	9 902 100.00	3	8 185 000.00	3
Netherlands	7 487 700.00	2	6 835 985.00	2
France	7 255 378.00	2	6 680 817.00	2
United Kingdom	6 316 000.00	2	5 815 000.00	2
Bangladesh	3 907 000.00	1	4 855 000.00	2
Canada	5 170 790.00	2	4 850 000.00	2
Iran	4 180 000.00	1	4 200 000.00	1
Turkey	4 800 000.00	1	4 170 000.00	1
Romania	4 230 210.00	1	3 985 000.00	1
Peru	2 996 090.00	1	3 284 223.00	1
Brazil	2 931 180.00	1	2 950 990.00	1
Japan	2 842 000.00	1	2 708 000.00	1
Belgium	3 229 622.00	1	2 653 949.00	1
Other countries	65 752 492.00	20	65 297 137.00	20
Total	330 434 205.00	100	323 215 561.00	100

In Belarus, in 2007, about 500 thousand hectares were occupied by potatoes (of which 455 thousand hectares were in private and dacha plots). The country harvests more than 8 million tons annually, ranking 8th in the world and leading in per capita production (700–900 kg). The average yield fluctuates from 160 to 190 c/ha, although breeders have set a goal to bring production productivity to 300 c/ha.

The genetic potential of modern cultivars under intensive technology reaches 60–70 t/ha. To achieve these figures, it is necessary to overcome the high cost of cultivation, equipment wear, as well as ensure timely plant protection and high-quality storage of tubers. Recent breeding efforts have been focused on developing highly specialized cultivars.

There are 76 potato cultivars included in the state registers, 38 of which are of domestic breeding, occupying 80% of the sown area. Over the last 15 years, 41 new cultivars of various maturity groups have been submitted for state trials, of which 31 are resistant to nematodes. Domestic potato cultivars have also been successfully included in the registers of Russia, Ukraine, Poland, Germany, China, and other countries.

Currently, a wide range of Belarusian cultivars is offered for production. The main criterion for classifying a cultivar into a specific maturity group is the number of days from planting to the natural senescence of the haulm: early-maturing — 50—60 days: Aksamit, Lazurit, Delfin, Kapriz, etc.; mid-early — 60—80 days: Prygozhy 2, Yavar, Dina, Orhideya, etc.; mid-season — 80—100 days: Altair, Dar, Dubrava, Skarb, Kolorit, Krinitsa, Rosinka, Zhivitsa, etc.; mid-late — 100—120 days: Blakit, Vetraz, Loshitskiy, Lasunak, Veras, Verba, Garant, Zhuravinka, etc.; late-maturing — 120 days or more: Alpinist, Atlant, Belorusskiy 3, Vytok, Zarnitsa, Zdabytak, Orbita, Pramen, Sintez, Suzorye, Temp.

Based on economic use and earliness, cultivars are classified as: table — tubers of high culinary quality, have thin skin and a small number of shallow eyes, early and mid-season; industrial — at least 18% starch — late-maturing, high-yielding, characterized by good storage life; fodder — increased content of dry matter and protein in tubers. Characterized by reduced starch content, low culinary quality, high yields; universal — in terms of tuber quality, they occupy an intermediate position between table and industrial cultivars. They are used for both food purposes and processing. 290 tuberous and root crops

According to their disintegration degree (culinary type), table cultivars are divided into four types:

• A — does not disintegrate (salad type);
• B — slightly disintegrates (boiled for soup, for frying);
• C — highly disintegrates (boiled for mashed potatoes);
• D — very highly disintegrates (boiled for mashed potatoes, for baking).

The history of potato growing, despite the virtues of the potato, was difficult and sometimes curious. Leo Tolstoy wrote: "Even the potato had to be introduced by force in our country."

To this day, there is no consensus among scientists regarding the origin of the potato. Some believe that the potato was brought from Peru, others claim that it traces its lineage to Chile, where the growing conditions are similar to those of many Western European countries with a moderately warm climate. However, there is no doubt that the homeland of the potato is South America, where it has been known since time immemorial.

Primitive tribes, driven by hunger, searched for edible plant roots in the earth, among which they found wild potato tubers. There are more than 150 of its wild species, growing mainly in South and Central America. From frozen tubers, the Indians prepared chuño — dried potato, which could be stored for a long time. For the Indians, the potato was a popular and essential food product.

There is no doubt that the Spanish were the first to discover the potato for Europe, finding starchy, good-tasting tubers in South America. They were looking for gold, but found the potato, thereby making a great botanical discovery. It is believed that in 1565, the potato was brought to Spain, allegedly by personal order of King Philip II.

From Spain, the potato made its way to Italy, where it spread rapidly. It began to be used not only for food but also for feed purposes. In 1588, Philippe de Sivry, a professor from the Belgian city of Mons, sent two tubers and a berry to Carolus Clusius, a botanist at the Vienna Botanical Garden, who examined the potato in detail in his 1601 book "Rariorum plantarum historia".

Clusius sent the grown tubers to the Swiss botanist Caspar Bauhin, who gave the new plant the name Solanum tuberosum (tuberous nightshade). This name has remained for the potato to this day.

It is believed that the road for the potato into France was opened by military pharmacist Antoine-Augustin Parmentier. To popularize this crop, he used an original method: he invited scientific luminaries to dinner and served them dishes made exclusively from potatoes, and in the suburbs of Paris, he begged the King for a plot of land, where, after planting potatoes, he stationed guards. In the autumn, when the potatoes were ripe, the guards would leave the site at night. Attracted by this ploy, the peasants would empty the beds and carry away the potatoes under the cover of darkness.

In addition, Parmentier suggested that King Louis XVI pin a bouquet of potato flowers to the lapel of his uniform, after which wearing these flowers became fashionable. The peasants living around Paris began to plant tubers to trade in potato flowers.

In honor of the first potato enthusiast, the French erected two monuments: near Paris, where the potato was first planted, and in Parmentier's homeland. One of them bears the words said to Parmentier by Louis XVI: "Believe me, the time will come when France will thank you for giving bread to starving humanity."

Peculiar methods of introducing the potato were used by Prussian kings: in 1651, Frederick William I issued a special decree according to which the noses and ears were to be cut off from those who refused to plant potatoes.

The Irish hold the potato in great esteem. "Potatoes and marriage are two things too serious to joke about."

There are known "potato riots" and even "potato wars" between Prussia and Austria over the Bavarian succession. The war of 1777 was called the "potato war" because both states sacrificed not people, but only destroyed the enemy's potato fields. Two years later, this bloodless war ended without a single battle.

A potato museum has been created in Belgium, with an exhibition containing thousands of items narrating the history of this valuable plant:

• potato peelers;
• postage stamps;
• paintings, poems, ballads, etc.

The appearance of the potato in Russia is associated with Peter I, who, while in the Netherlands at the end of the XVII century, became interested in the wonderful plant and sent a sack of tubers to Count Sheremetev for "breeding".

The efficiency of the development of potato growing in the Republic of Belarus since the mid-XX century was largely facilitated by the scientific research of P. I. Alsmik, I. I. Adamov, N. A. Dorozhkin, and others at the BelNIIKPO opened in 1956.

Under the guidance of Academician P. I. Alsmik, over 100 scientific papers were published, addressing scientific and industrial problems of potato production. The scientist’s practical contribution to potato breeding is impressive. He developed more than 30 cultivars:

• Loshitsky;
• Temp;
• Razvaristy;
• Belorussky-3;
• Verba, etc.

Cultivars of Belarusian breeding occupied over 30% of the sown areas of the USSR. In 1974, a group of scientists from this institute (headed by P. I. Alsmik) was awarded the USSR State Prize for the development and introduction into production of high-productivity potato cultivars. Today, the doctors and candidates of sciences trained by him continue to work on the development of new potato cultivars. 292 tuber and root crops

Potato is a perennial herbaceous tuber-bearing plant. In cultivation, it is grown as an annual because its entire life cycle, from the sprouting of the tuber to the formation and development of mature tubers, takes place within one growing season.

Usually, potatoes are propagated vegetatively — by tubers. It can also be successfully propagated by other methods:

• parts of tubers;
• sprouts;
• cuttings.

In breeding practice, seed propagation is often used.

The potato belongs to the Solanaceae family, the genus Solanum, which unites dozens of wild and cultivated species, including Solanum tuberosum L. — the species that has become the most widely distributed in cultivation.

Thanks to expeditions and introduction work by scientists (S. M. Bukasov, S. V. Juzepchuk, N. I. Vavilov, et al.), a number of new species of wild and cultivated potatoes were discovered in Central and South America — Solanum demissum, S. andigenum, S. curtilobum, etc., which are successfully used for hybridization and the creation of new valuable frost-resistant, late blight-resistant, and wart-resistant cultivars. However, out of the 26 currently known species of cultivated potatoes, only a few thousand cultivars of S. tuberosum are widely cultivated worldwide.

The root system of the potato is of two types: in seedlings, it consists of a main, taproot and lateral roots. In a potato grown from a tuber, the root system is fibrous, formed by adventitious roots extending from the underground part of the stem and from the nodes of stolons. The potato root system is relatively weakly developed.

The bulk of the roots is located within the depth of the plough layer, with some penetrating down to 70—80 cm. In early cultivars, the depth of root penetration into the soil is smaller, while in mid-season and late cultivars, it is greater. The ability of potato roots to overcome the mechanical resistance of the soil is low. The root system is characterized by high absorption capacity, especially in relation to phosphorus.

Potato above-ground stems are herbaceous, mostly erect, less often leaning to the side. Stem color is green, reddish-violet, or bluish-violet due to the presence of anthocyanin. The stems are three- or four-sided in cross-section, less often round, and are pubescent to varying degrees. The stem has wings — ribbon-like outgrowths between nodes. The number of stems in a bush varies by cultivar from 3—5 to 10—12.

According to the branching pattern of the stem, cultivars are divided into two groups:

• branching occurs mainly in the lower tier (late-ripening cultivars);
• the stem does not branch at the bottom (early-ripening cultivars).

From the axils of rudimentary leaves of the underground part of the stem, underground tuber-bearing shoots called stolons are formed. 6—8 stolons are formed on one plant, which may branch. The length of each stolon is 15—20 cm (sometimes 50 cm).

Fig. 40. Potato: morphological features (a: 1 — leaf, 2 — stem, 3 — root neck, 4 — stolon, 5 — new harvest tuber at the initial stage of development, 6 — eyes, 7 — roots, 8 — mother tuber; b — in the field; c — flowers; d — multi-colored tubers; e — healthy tuber with sprouts and in cross-section; f — affected by late blight) 294 tuber and root crops

Tubers are formed at the ends of stolons (underground modifications of shoots). In a tuber, one can distinguish the base — the place of attachment to the stolon; the opposite end — the apex. On the tuber, one can see reduced leaves (visible at an early age as small scales, which atrophy as the tuber grows, and their leaf scar forms a ridge — the brow).

In the axils of the reduced leaves are the eyes, each having three buds. The eyes on the tuber are arranged in a spiral. The largest number of eyes (buds) is located at the apex, and the smallest — at the base of the tuber. Usually, the most viable bud sprouts first. Only when the sprout is broken off or damaged does the next bud begin to grow. The eyes of the apical part of the tuber are more viable and sprout earlier than the lower ones.

There is a definite connection between the number of stems and the quantity, as well as the size of the tubers:

Bush type	Number of tubers	Tuber size
Few-stemmed	5—10	Large
Multi-stemmed	20—25	Small

Cultivars with a large number of stems produce more tubers, but they are smaller, which is economically more feasible, as tubers weighing 50–150 g are more resistant to mechanical damage than large ones and have better storage performance in winter.

Physiological requirements and developmental stages of potato

In field conditions, it is important to understand the morphology and development characteristics of potato. Its leaves are usually pubescent (sometimes smooth), simple, interrupted-odd-pinnate, and spirally arranged. The leaf consists of a single terminal leaflet on the central petiole, lateral leaflets, and smaller leaflets between them: a highly dissected leaf has more than 10 pairs of them, while a slightly dissected one has only 2–3. Flowers are gathered in cymes on a common peduncle, bloom from bottom to top, and have a wheel-shaped corolla of white, blue, blue-violet, or red-violet color.

Potato is predominantly a self-pollinating plant, but cross-pollinated specimens also occur. The fruit is a juicy multi-seeded berry that turns white upon ripening and acquires a pleasant strawberry scent, but is inedible due to its high solanine content. Small, flattened seeds weighing about 0.5 g per 1000 pieces are used only for breeding and developing new cultivars.

The crop imposes strict requirements on soil and air temperature. For the start of the growing season, the soil at the planting depth must warm up, and overheating or frosts can completely destroy the harvest or halt its development. The optimal acidity level for cultivation is within the pH 5.3–5.8 range.

• Soil temperature for planting — 7–8 °C
• Tuber planting depth — 6–12 cm
• Optimal germination temperature — 15–20 °C
• Optimal soil temperature for tubers — 17 °C (19 °C for mid-late varieties)
• Dangerous frost for seedlings — from −0.5 to −1.0 °C
• Soil acidity (pH) — 5.3–5.8

The water demand of potato changes unevenly throughout the season. At the beginning of the growing season, moisture is consumed economically, but during the phases of active foliage growth, flowering, and tuberization, water consumption increases sharply. Most cultivars are long-day plants, which stimulates foliage growth, but short days are required for tuber set in the dark. The crop thrives best on light and medium soils — sod-podzolic, sandy loam, and sandy soils underlain by moraine.

Potato development is divided into four clearly defined phases. Their duration directly depends on the maturity group of a specific cultivar and weather conditions. Timely monitoring of these phases allows the agronomist to accurately plan treatments and estimate yield potential.

Developmental phase	Timing	Physiological characteristics
Emergence	10–25 days after planting	Active growth of roots and above-ground mass begins. An air temperature of 18–25 °C is optimal for foliage development.
Budding	Upon appearance of buds	Stolons are established in the soil, and the formation of the first tubers begins.
Flowering	30–35 days after emergence (40–45 days for late varieties)	Foliage growth ceases. All of the plant's energy is redirected to tuber bulking.
Ripening	55–65 days after flowering	Leaves turn yellow, foliage dies off (it remains green until frost in late cultivars). Tubers accumulate starch and develop a firm skin.

Position in crop rotation and soil preparation

Potato tolerates monoculture better than other crops, however, continuous cultivation in the same place reduces harvest quality. Choosing the right predecessor helps control the spread of diseases and pests without excessive pesticide load. Cereals and grain legumes, sugar beet, flax, and millet are considered good predecessors.

The crop is extremely sensitive to soil compaction and waterlogging. Deep and high-quality tillage is required to create an optimal water-air regime. The main complex of work begins in the autumn, immediately after harvesting the preceding crop.

1. Stubble cultivation. Performed after harvesting the predecessor, but no later than 7 days after, to a depth of 6–12 cm.
2. Autumn ploughing. Carried out 2–3 weeks after stubble cultivation (no later than the second ten-day period of September) to the depth of the arable horizon with simultaneous application of organic fertilizers.
3. Spring moisture conservation. First cultivation to a depth of 5–7 cm to prevent moisture evaporation.
4. Pre-planting cultivation and ridging. Second cultivation immediately before planting to a depth of 18–20 cm. It is performed at a 45° angle to the direction of ploughing, and each subsequent operation is performed in a diagonal-cross direction relative to the previous one.

When tilling sandy and sandy-loam soils that are free of rhizomatous weeds, as well as after green manure crops, deep loosening to a depth of 35–40 cm is performed in autumn instead of ploughing. If organic fertilizers are applied in autumn on light and medium soils, it is permissible to replace autumn ploughing with double-track cultivation to a depth of 18–20 cm. This helps maintain the structure of light soils and ensures uniform distribution of organic matter within the cultivated layer.

Planting and Fertilization System: From Tuber Preparation to Ridging

• Soil temperature for planting — 7–8 °C
• Planting density for technical purposes — at least 40 thousand tubers/ha
• Rate of organic fertilizers — 50–60 t/ha
• Mandatory phosphorus in rows during planting — 20–30 kg/ha P2O5
• Harvesting duration for one cultivar — no more than 7–10 days

Ridging warms the soil in the tuber zone by 3–4 °C, which accelerates emergence by 5–6 days. If ridging is combined with planting, potatoes will mature faster. On medium and heavy soils, ridges are prepared in advance — 3–7 days before planting.

Soil type	Ridge height, cm
Loamy	12–14
Light	14–16

To achieve high potato yields on sod-podzolic loamy and sandy-loam soils, the foundation of nutrition is established with organic fertilizers. Apply rotted strawy manure or peat-manure composts in autumn or under the preceding crop.

Mineral nutrition is applied via broadcast before planting or locally directly at planting. Nitrogen fertilizers are distributed in spring in a single application under cultivation or before ridging. Phosphorus fertilizers can be applied in autumn for autumn ploughing or in spring during pre-sowing cultivation, but local application of phosphorus in rows is a mandatory practice. Potash fertilizers are more effective on cohesive soils when applied in autumn for autumn ploughing.

For a target yield of food and technical potatoes of 15–20 t/ha on soils with low nutrient content (P2O5 less than 100 mg/kg, K2O less than 80 mg/kg), target the following application rates of active ingredient:

Nutrient	Mineral fertilizer dose, kg active ingredient/ha
Nitrogen (N)	50–70
Phosphorus (P2O5)	60–80
Potassium (K2O)	70–90

Healthy tubers weighing 50–90 g are selected for planting. Chitting — sprouting seed material in light at a temperature of 15–18 °C for 25–40 days — accelerates emergence, stimulates plant development, and increases overall yield. Immediately before planting, the tubers are treated with Fundazol, Vitavax 200, Dithane M-45, or their analogues.

Crop Care, Pest Protection, and Harvesting

Optimal calendar planting dates for the southern regions of Belarus start from April 20, and for the northern ones — last until May 10. Potatoes are planted using the ridging method with a row spacing of 70–90 cm. The rows are directed across the pre-planting tillage; the optimal vector is from north-west to south-east.

The consumption of planting material for food purposes depends on the seed tuber fraction:

Tuber size, mm	Planting material consumption, t/ha
25–35	1.5–2.0
35–60	2.0–3.5

Planting depth of tubers from the top of the ridge varies by soil type: on loams it is 6–8 cm, on sandy loams and sands — 8–10 cm, on peat soils — 12–14 cm. Planting density for food potatoes should be at least 35 thousand tubers per hectare, and for technical purposes — at least 40 thousand.

The pre-emergence period for potatoes lasts from 10 to 30 days. The crop care plan during this time follows this algorithm:

1. 5–7 days after planting, perform the first ridging with harrowing to a depth of 6–8 cm to break the soil crust and destroy weed seedlings.
2. 5–6 days after the first pass, carry out a second treatment to a depth of 10–15 cm followed by the application of soil-applied herbicides.
3. Perform post-emergence inter-row treatments to form the ridge profile until the canopy closes in the rows.

Weeds are eradicated in three stages: in autumn after harvesting the previous crop, in spring before potato emergence, and during the growing season, by combining mechanical treatments with chemical ones.

To protect against late blight, fungicides are used: Acrobat MC, Brestanid, Dithane M-45, copper oxychloride, Ridomil, and others. The first preventive spraying is carried out when plants reach a height of 15–20 cm, the second — after 7–8 days. Subsequent treatments are planned based on short-term weather forecasts: repeat every 7–8 days during a dry period and every 4–5 days during rainy weather.

Control of the Colorado potato beetle begins as soon as there is emergence. If the timing for treatments against the pest and late blight coincides, an insecticide (Karate, Belofos, or similar) is added to the fungicide in a single tank mixture.

Harvesting begins in late August to early September. Haulm topping is carried out in advance: 5–7 days before harvesting on food-crop plots and 12–15 days on seed crops. This promotes hardening of the tuber skin and reduces damage during digging.

After digging, potatoes undergo post-harvest processing: cleaning from soil and plant debris, calibration by size fractions, and culling of diseased and damaged tubers, after which they are put into storage.

Before storage, the tubers must be sorted and dried. Potato storage often lasts up to 230 days.