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Peas

Peas are a leguminous agricultural crop.

Economic importance

Peas account for about 80% of all sown areas of leguminous crops in Russia. Peas are of food, fodder and agrotechnical importance in agriculture.

Their seeds are notable for their digestibility and high taste qualities. Mature, immature seeds (green peas) and green beans (vegetable varieties) are used in the canning industry.

Green peas contain 25-30% sugars, vitamins A, B1, B2 and C, minerals. Pea seeds contain 23-30% protein.

Pea-grass mixtures are grown for silage, green fodder and hay. 1 kg of green matter equals 0.13 fodder unit and contains 25 g of digestible protein. 1 kg of seeds is equal to 1.17 fodder unit and contains 180-240 g of protein. 1 kg of hay contains up to 13% protein. Pea meal is used in livestock farming as a concentrated feed for livestock. Shredded grain, chaff and green mass are used for feeding purposes. Earlier pea straw was used as a fodder. Its protein content amounted to 6-8%, and 1 kg contained 0.23 fodder units and 31 g of digestible protein. Recently, it has been used more often as an organic fertilizer.

Pea plants are capable of nitrogen fixation: 1 ha of crops can remain up to 50-70 kg/ha. In rotation it is a good predecessor for many crops. Thanks to the short vegetation period peas is well suited as an intermediate, fallow-occupied crop or a green fertilizer.

History of the crop

Peas are one of the oldest crops, even in the Stone Age 20,000 years ago they were used as food. According to archaeological excavations, the homeland of sown peas is the areas of Fore Asia, i.e. Transcaucasia, northwest Iran, mountainous Turkmenistan, Afghanistan and India, where small-seeded forms were grown. According to N.I. Vavilov, the large-seeded forms of peas originate from the second center – the Eastern Mediterranean.

According to archaeological excavations in Chernivtsi and Ivano-Frankovsk regions in Eastern Europe peas appeared probably in the III-II millennium BC. In Russia it is known since VI-VIII centuries.

Cultivation areas and yields

In 1980 pea was cultivated on about 15 million hectares in the world, with an average yield of 1.4 t/ha. By the end of the 20th century pea was 7 million ha, or 4.2% of the legume-crops cultivated area. It is cultivated in many European countries, in the USA, Canada, China, India and Australia. The gross grain yield is 12 million tons or 5.3% of the total legume grain production, with an average yield of 1.8 t/ha.

The area under crops in the USSR was 5 million hectares in 1983. In Russia at the beginning of the 2000s, the area was 0.5 million hectares or 42% of the area of leguminous crops. The gross output is 1.2 mln tons or 66.7% of the grain yield of this group, with the average yield of 1.2-1.4 t/ha.

Peas are cold-resistant, early maturing, undemanding to the soil. In Russia peas are grown in most regions of the world, up to 65° N. latitude. (early maturing varieties grow as early as 68° N), but the main crops are concentrated in the Central Black Earth zone and the central part of the Non-Black Earth zone, in Tatarstan, Chuvashia, Mordovia, Bashkiria, and in the northern Caucasus. In the former USSR, it is also cultivated in the forest-steppe and right-bank Ukraine, Belarus and the Baltics.

Thanks to the development of early maturing and drought-resistant varieties, pea crops have spread in Western and Eastern Siberia, the Urals, and Kazakhstan. However, because of its poor drought tolerance and susceptibility to pea bruchus, it is rarely grown in the southern and southeastern regions. In Central Asia and Transcaucasia, wintering varieties of peas are sown in autumn.

Among leguminous crops, peas are one of the leading crops by yield. High yields were obtained at the Novoanninskiy variety plot in Volgograd Region and amounted to 6.43 t/ha. Under optimal growing conditions, peas can produce high yields on large areas. For example, in 1982. in Korenevsky district of Krasnodar Krai (collective farm “Pobeda”) the seed yield was 4.52 t/ha (sowing area 138 ha); in Alexandrovsky district of Stavropol Krai (collective farm “Komsomolets”) – 3.24 t/ha (700 ha); in Yalchinsky district of Chuvashia (collective farm “Pobeda”) – 2.92 t/ha (640 ha); in Ruzaevsky district of Kokchetav region (in the state farm “Valikhanovsky”, Kazakhstan) – 3.79 t/ha (630 ha).

Botanical description

Peas (Pisum L.) are represented by several species, the main of which is the cultivated pea (P. sativum L.) – polymorphic, the most common species. It includes subspecies:

  • pea common sowing (Pisum sativum) – with white flowers, light single-colored spherical (in some forms wrinkled) seeds of white, pink, green, yellow color with light scars, weight of 1000 pieces 150-340 g;
  • field peas, or pelushka, (Pisum arvense) – with red-purple flowers and dark, usually mottled angular seeds with small indentations and brown or black welt; stipules have red anthocyanin (purple) spots; peels are gray-green, black or brown.

Pea sowing is subdivided into a peeling variety and a sugar pea variety. Pea peeling varieties have a tough parchment layer in the walls of the bean, and are grown mainly for grain. Sugar varieties do not have a parchment layer; beans in their green state can be used for food purposes and are grown mainly for vegetables.

Field peas (pelushka) have fodder value, less often as a green fertilizer, and are grown for seed, hay, and green fodder. It may be cultivated on poor sandy and peaty soils, is very early maturing, and its seed production is stable even in the north, for example, in Vologda and the Komi Republic.

The root system is taproot, penetrating to a depth of 100-150 cm.

The stem is loping, up to 80-100 cm high. Stem varieties have thickenings at the top of the stem and short internodes because of which they are resistant to lodging.

Leaves are compound pairs, pinnate, ending in branching tendrils. At the base of the leaf has two large stipules, the pelushka has a purple spot.

The inflorescence is a monoflowered or biflowered cluster.

The fruit is a multiseeded pod with 3-10 seeds. The stem forms 2-5 fruiting nodes. Seed ripening begins from the beans of the lower nodes.

Biological features

Temperature requirements

Demanding to heat is low, cold-resistant. Seeds germinate at temperatures of 1-2 °C. The optimal temperature for seedlings to appear is 6-12 °C. Sprouts can survive frosts as low as -6 … -8 °C.

High temperatures during flowering and ripening periods and dry winds decrease crop yield.

Cultivated in the south are winter and winter hardy forms that are able to withstand mild winters.

Forage pea varieties are more frost-resistant.

Frosts of -2 … -3 °C during the fruiting period may cause beans to freeze.

Moisture requirements

Peas are relatively damp-loving crops. They are sensitive to moisture before they start flowering.

For swelling and germination of seeds 110-115% of the weight of the seeds is required.

It is somewhat more drought-resistant than fodder beans, vetch and lupine, but less so than cicer, lathyrus and lentil.

Transpiration coefficient is 400-600 (400-450). Water requirements are reduced by 10% with good phosphorus-potassium nutrition.

Light requirements

Refers to light-loving plants of long daylight hours. For this reason in northern areas the growth and development of peas is a little faster.

Soil requirements

Pea plants are very demanding in terms of soil fertility and moisture, since they have time to form a large ground mass if their root system is relatively weak.

Optimal soils are chernozem soils of medium cohesion, well moistened and limestoned, gray forest, cultivated sod-podzolic, chestnut soils.

Dense, heavy, light sandy, acidic, solonetzic, boggy soils with groundwater occurrence less than 60-80 cm are not suitable.

Optimum soil acidity is pH 6-8.

Vegetation

Peas are an annual early-ripening spring crop. There are also wintering forms cultivated in the south.

Growth phases:

  • sprouting;
  • budding;
  • flowering;
  • ripening.

The growing season varies from 60 to 140 days depending on cultivar and growing conditions.

Plants are self-pollinated, but in hot and dry years, open flowering is possible and some cross-pollination occurs.

Peas grow slowly during their early stages of development so controlling weeds is very important.

Root tubers are formed 7 to 10 days after sprouting (from the phase of 5 to 8 leaves).

Maximum growth is observed from the beginning of flowering to the beginning of ripening.

Flowering lasts 10 to 30 days, and 6 to 8 days in drought conditions. Movement of plastic substances from leaves and stems to seeds is completed in the phase of proteinous ripeness, at which moisture content is 35-40% at the beginning of the phase, and 20-25% at the end of the phase.

Crop rotation

When placing crops in the rotation, the relief and exposure of slopes are taken into account. In dry conditions it is better to sow peas in low places to reduce the impact of moisture deficit. In northern areas, on the contrary, the crops are placed on the elevated terrain for better and faster warming.

It is preferable to sow peas after well fertilized preceding crops, such as cereals (spring and winter) and row crops (sugar beets, potatoes, corn, flax).

Peas are bad for permanent crops and repeated sowing, which is associated with infestation by root rot and “pea fatigue”. Return it to its original place no earlier than 5-6 years later.

Bad predecessors are sunflowers because of fallen seeds, which clog subsequent crops, and legumes because of common pests and diseases.

In the rotation, the distance between legume fields should be at least 500 m.

Peas are a good predecessor for winter and spring cereals and technical crops.

Fertilizer system

Peas are responsive to the application of organic fertilizers under the preceding crops. It is recommended to apply mineral fertilizers directly under peas.

For the formation of 1 ton of seeds and the corresponding amount of straw peas from the soil consumes 45-60 kg of nitrogen, 17-20 kg of phosphorus, 35-40 kg of potassium, 25-30 kg of calcium.

Peas also respond well to the application of microfertilizers, especially molybdenum and boron.

Of the calculated requirement of peas in nitrogen, as a rule, only 30% or less, the rest it provides through nitrogen fixation. Under favorable conditions, when nitrogen fixation is most productive, nitrogen fertilizers can be abandoned. Phosphorus, on the contrary, apply 1.5 times more of the calculated amount.

Liming of soils is of great importance, as neutral acidity promotes symbiotic nitrogen fixation.

On soils with a high state of cultivation after fertilized predecessors, ie, when the available forms of phosphorus and potassium over 15 mg per 100 g of soil, pea yield can be 3 t/ha of grain even without fertilization.

With a low content of humus (less than 2%), phosphorus and potassium (less than 5-10 mg per 100 g of soil), make full mineral fertilizer. At the same time phosphorus and potassium are made taking into account the planned yield, nitrogen – taking into account the amount of absorbed atmospheric nitrogen.

Phosphorus-potassium fertilizers are made under the main tillage in the amount of P60-80K50-60, nitrogen – under pre-sowing cultivation.

Peas is able to absorb phosphorus from sparingly soluble compounds, so as a phosphorus fertilizer for it can be used phosphorite flour in an amount of 300-500 kg/ha.

Good results are obtained by row application of phosphate fertilizers during sowing in the amount of P10-20. In the Non-Black Soil Zone more effective when applied to the rows of complex granular fertilizers, the rate of phosphorus is the same.

The effectiveness of boric and molybdenum fertilizers associated with their influence on the activity of symbiotic microorganisms. These fertilizers are applied when the content of molybdenum and boron in the soil is below 0.3 mg/kg. For this purpose, molybdenum granulated superphosphate can be used, which is applied at sowing in the rows, or do pre-sowing treatment of seeds with microfertilizers. Boric fertilizer is effective on acidic sod-podzolic and gray forest soils after the introduction of lime fertilizers. It is advisable to treat seeds with one micronutrient treat the seeds, the second to put in the soil during sowing.

Tillage

The main tasks of tillage when growing peas are weed control, moisture retention, and leveling. Tillage, in general, is similar to tillage for early spring cereals.

The main treatment includes stubble discing and plowing. If root-shoot weeds are clogged, 2 weeks after the first discing, i.e. when leaf rosettes appear, the second one is made to a depth of 10-12 cm. After plowing with plows with skimmers.

To combat rhizomatous weeds perform discing in perpendicular directions with heavy disc harrows БДТ-7, 0 on 10-12 cm. After the emergence of wheatgrass sprouts, deep plowing is carried out.

In steppe regions, where there is a risk of wind erosion, treatment is carried out in layers: 1-2 stubble discing at 8-10 cm, then deep loosening with plowshare to a depth of 22-25 cm.

In dry conditions in winter, snow and melt water retention is carried out.

The task of pre-sowing tillage is loosening the seed layer and leveling the surface of the field for subsequent uniform seeding. It includes early spring harrowing, surface leveling with heavy toothed harrows БЗТС-1,0 type, one cultivation on 8-10 cm in the unit with medium harrows across or diagonally to the direction of the main plowing.

At flat-cutting in autumn, in spring the moisture is closed using needle harrows БИГ-ЗА, for pre-sowing loosening special cultivators are used.

Sowing

For sowing peas, row-row seeders are used, such as С3-3,6, СЗА-3,6, СЗП-3,6. These seeders allow sowing seeds deeper than narrow-row seeders, and are less likely to get clogged in wet soil. For better penetration into the soil of coulters following the tracks of tracks or wheels of the tractor, on the lower links of the rear linkage of the tractor mounted ripper, which consists of a beam and articulated sections of the cultivator КРН-4,2 with chisels. On the tractor hitch, sowing or medium harrows are additionally installed on the tractor tracks for leveling the soil after the rippers. The speed of the unit should not be more than 5-6 km/h.

In areas where the flat-cutting is used, СЗС-2,1 seeders are used.

Seed preparation

To stimulate the processes of symbiotic nitrogen fixation, carry out preplant treatment of the seeds with bacterial fertilizers, such as rhizotorfin.

Sowing times

Early sowing dates of peas are preferred in all the major areas of cultivation with the exception of Western Siberia and northern Kazakhstan, where sowing is carried out in the second half of May because of the risk of June drought. As a rule, the optimal sowing dates coincide with the optimal dates for early spring cereals.

Delayed sowing of peas by 7-12 days leads to a decrease in yield in the Non-Black Soil Zone by 0.2-0.3 t/ha, in the forest-steppe part of the Black Earth zone – by 0.3-0.5 t/ha.

Sowing methods

Peas are sown by the row method, less often by narrow-row and cross-row methods. These methods reduce lodging, facilitate harvesting, reduce crop losses and produce the highest yields.

There should be no more than 6 hours between the pre-sowing tillage and sowing.

Seeding rates

The optimum seeding rate for fine and medium sized pea varieties in the arid zone, for example, in the Volga region, Kazakhstan, Kyrgyzstan, is 0.8-0.9 million/ha of germinated seeds. In the steppe areas, for example, in the Urals and Siberia – 1 million/ha. In the zone of sufficient moisture: the north-west of the European part, Central Black Earth and Non-Black Earth zone, the Volga-Vyatka region, Polesie and steppe forests of Ukraine, Belarus, the Baltic countries seeding rate is 1-1.3 million/ha of germinated seeds. In the case of harrowing, the rate is increased to 1.4 million/ha of germinating seeds.

For coarse-grained varieties, the seeding rate is 0.8-0.9 million/ha of germinating seeds.

Weight seeding rates are: for small-seeded varieties – 150-250 kg/ha, large-seeded – 240-300 kg/ha.

Sowing depth

The sowing depth of peas, as a crop with larger seeds, is greater than that of cereals. The depth is determined by soil and meteorological conditions. For the Black Earth zone it is 6-8 cm, in arid areas – 8-10 cm.

Peas are well tolerant of deep embedding, which allows sowing in dry conditions, where the top soil quickly dries out, to deeper layers.

In cool and wet spring, the depth is reduced to 5-7 cm, in heavy soils of northern areas – to 4-5 cm.

Small-seeded varieties and with early sowing, the depth is reduced by 1-2 cm.

Crop care

Pea crop care includes weed, disease and pest control.

After sowing in dry weather, the soil is rolled with the use of ring-spiked rollers ЗККШ-6. The method is effective in most cases, except for wet and heavy clay soils.

To control weeds carry out preemergence and postemergence harrowing which allows to reduce by 60-80% weed infestation of crops by annual weeds. Pre-emergent harrowing is done 4-5 days after sowing when weeds reach the white threads phase. Harrowing on the shoots is carried out in the phase of 2-5 leaves of pea plants before the formation of tendrils and mass growth of weeds. Harrowing is carried out in the daytime only across the rows or diagonally by harrows with retracted tines at a speed not exceeding 6 km/h.

Light harrows or reticulated harrows such as ЗБП-0,6А and БСО-4А are used for harrowing on light soils, medium and heavy – medium tooth harrows, for example, БЗСС-1.0.

Preparations against diseases

Fusarium root rot – Phytosporin-M (titer not less than 2 billion living cells and spores in 1 g of Bacillus subtilis, strain 26D), pre-sowing treatment of seeds.

Rust and powdery mildew – Alto (400 g/l, ciproconazole), spraying during vegetation.

Ascochytosis, rust, powdery mildew, chocolate leaf spot – Rex Duo (310 g/l thiophanamethyl + 187 g/l epoxiconazole), spraying during vegetation.

Harvesting

Many pea varieties are characterized by strong lodging, low pod attachment on the stems, uneven and prolonged ripening, bean bursting, shattering of seeds, their damage during threshing. For these reasons, the two-phase harvesting method is preferable. Premature harvesting leads to wrinkled seeds, while delayed harvesting leads to shattering and loss of the crop. 

During the two-phase harvesting, mowing in swaths is carried out when 60-75% of beans are browned (turned white, yellow), seed moisture is 30-40%, and the seeds are fully formed and hardened. During this period, the beans of the upper layer are pale green, the stems and leaves are yellow. Mowing is carried out by the reapers type ЖБР-4,2 at a speed of 5 km/h, or by mowers КС-2,1, equipped with a device ПБА-4 or ПБ-2,1 at a speed of 6-7 km/h.

Mowing direction is across the lodging, for short-stemmed varieties – towards the direction of lodging. When seed moisture of 16-19% is reached, the threshing of swaths is carried out, usually after 3-4 days in good weather. At humidity less than 15% there is a strong crushing and losses from shattering, and at humidity more than 20% – damage to the germs of seeds.

To pick up the windrows combine harvesters are equipped with conveyor copy pickers ППТ-3, ППТ-ЗА. To prevent re-entry of grain into the drum fully open the louvers of the grid and increase blowing.

The method of direct combine is used on poorly lodged crops of short-stemmed and not shrinking varieties. Typically, this method peas are harvested in the Volga region, Eastern Siberia, the steppe regions of Ukraine, where, provided the fields are clean of weeds and uniform maturation, one-phase method often has an advantage. Harvesting begins when the seeds reach full ripeness. For this method, combine harvesters are equipped with spring-loaded stem lifters. The threshing units are adjusted in the same way as in swath pick-up.

Table. Operating modes of threshing machines

Indicator
Dry threshed mass of peas
Wet threshed mass of peas
СК-4
СК-5
СКД-5
СК-4
СК-5
СКД-5
Rotation frequency, rpm
1 reel
400
400
500
500
500
600
2 reel
650
750
Gaps between reel whips and deck strips, mm
1 reel
inlet
25
28
30
20
24
25
in the middle part
25
20
out
13
13
15
8
8
10
2 reel
inlet
24
20
out
12
7

A combination of the two harvesting methods is possible, with direct harvesting carried out on clean fields at full ripeness and grain moisture of 16-19%.

Both methods are suitable for harvesting moustached pea varieties.

Seeds coming to threshing floor cleaned and dried to a moisture content of 12-14%.

Mixed crops of peas and oats also use double threshing, which threshes mature beans at a reduced frequency of drum rotation to 400-500 revolutions per minute. The remaining unripe beans are dried in windrows for 3-4 days and subjected to a second threshing process. 

Selection work is aimed at developing varieties that are more resistant to lodging and shattering.

Desiccants

Reglon Super, spraying 7-10 days before harvesting.

Resource-saving intensive technology

Resource-saving intensive technology
Resource-saving intensive technology of peas cultivation allows to get the yield up to 3-4 t/ha. It provides for the placement of crops on the best well-fertilized predecessors. Tillage system should provide maximum field clearing of weeds and leveling of the soil surface.

Fertilizer rates are calculated for the planned yield, taking into account the content of phosphorus and potassium in the soil. Under the predecessor make organic fertilizers. Applied phosphate fertilizer in the rows during planting. If there is a deficit of trace elements in the soil, apply microfertilizers, especially molybdenum and boron.

Seed pre-sowing treatment includes treatment with rhizotorfin or similar preparations, and, if necessary, with microfertilizers.

The sowing dates are the earliest in all zones, except for Western Siberia, where sowing is carried out in the second half of May.

Sowing care primarily involves the control of weeds, diseases and pests. Pre-emergence (4-5 days after sowing) and post-emergence (in the phase of 3-5 leaves of the crop) harrowing is carried out.

Sources

V.V. Kolomeychenko. Horticulture/Textbook. – Moscow: Agrobiznesentr, 2007. – 600 с. ISBN 978-5-902792-11-6.

Horticulture/P.P. Vavilov, V.V. Gritsenko. Vavilov. ed. by P.P. Vavilov, V.S. Kuznetsov et al. – M.: Agropromizdat, 1986. – 512 p.: ill. – (Textbook and Tutorials for Higher Education Institutions).

Fundamentals of agricultural production technology. Farming and plant growing. Ed. by V.S. Niklyaev. – Moscow: “Bylina”. 2000. – 555 с.