History and prospects of pea cultivation in Belarus

Pea cultivation in Belarus: potential and selection of cultivars

The pea is the main grain legume crop of Belarus, cultivated primarily for forage purposes and green mass production. With high-level agricultural practices and proper cultivar selection, the crop provides stable yields of about 43 c/ha. Currently, there is a clear trend in the republic toward expanding the acreage under peas for marketable grain production.

• Yield potential with high-level agricultural practices — ~ 43 c/ha
• Average yield in farms — 19.5 c/ha
• Total sown area in the republic — about 25 thousand ha
• 1000-seed weight — 150–340 g

In 2007, the sown area under peas in Belarus reached 45 thousand ha, with an average yield of 24.2 c/ha. At that time, the cropping pattern was based on three cultivars: Vegetativny Zhelty, Ustyanovsky, and Gomelsky. Simultaneously, variety trial results show much higher productivity of promising cultivars.

In Belarus, pea cultivars such as Belus, Belarus, Agat, Svitanak, Alex, Millenium, and Dovsky Usaty are recommended for cultivation. The correct choice of cultivar for specific soil and climatic conditions allows for a significant increase in grain yield. This helps agronomists use the production potential of fields more effectively.

History of the crop and morphological characteristics of species

The pea is one of the oldest agricultural crops with its primary center of origin in Afghanistan. The first archaeological finds of its seed in Neolithic layers confirm a thousand-year history of cultivation. Sanskrit tribes of Central Asia introduced it into cultivation under the name "kharenso," from where it reached China in the 1st century and spread throughout its territory by the 4th century. In the Minsk region, peas were cultivated as early as the 6th–8th centuries, whereas in England and Northern Europe, the crop became known only by the 5th century and spread widely by the mid-11th century. Peas were brought to America after Columbus's expeditions, and in the 17th–18th centuries, they took an important place in local agriculture.

There are two main geographical centers of origin for the garden pea. Western Asia (Asia Minor, Transcaucasia, Iraq, Iran, and mountainous Turkmenistan) is the homeland of small-seeded forms. The Eastern Mediterranean is considered the home of large-seeded varieties of the crop.

In domestic plant growing, two species of peas are cultivated, which are also classified as subspecies of the common pea. They have distinct morphological differences that are important for determining the purity of crops. Specialists differentiate them by flower color, seed shape, and the structure of vegetative organs:

• Garden pea (Pisum sativum L. / ssp. sativum) — most common in cultivation. It has white flowers, green leaves without anthocyanin, and seeds that are spherical, smooth or wrinkled, pinkish, with a colorless seed coat and a light (rarely dark) hilum.
• Field pea, or Austrian winter pea (Pisum arvense L. / ssp. arvense) — flowers are violet or pinkish-red; leaves are green with violet (anthocyanin) spots on the stem and at the base of stipules, which are often serrated at the edges. Seedlings have anthocyanin-colored petioles and spots around the stem. Seeds are round-angular, smooth with small indentations, with a brown or black hilum; the seed coat color is gray-green, brown, or black, solid or spotted.

Based on the structure of the pods, cultivars are divided into three groups. Each group has its own economic purpose and processing characteristics. This determines the final marketing channels for the harvest:

• Shelling: characterized by the presence of a leathery parchment layer in the pod walls, which makes green pods unsuitable for food.
• Sugar: lacks a parchment layer in the pods; immature pods are tender, fleshy, and sweet, and can be used for fresh consumption and canning.
• Wrinkled: ripe seeds are wrinkled and look like a brain. They contain 6–9% sugar (sucrose), have a very sweet taste, and are used in the canning industry (light-colored cultivars — for canned peas in brine, dark-colored — for freezing), but are poorly suited for soups.

The pea stem can be thin and lodging or thickened and non-lodging — such forms are called determinate (dwarf/bush). According to seed size, cultivars are divided into small-seeded and large-seeded, and their color varies from yellow-pink to green. The weight of 1000 seeds ranges from 150 to 340 g.

Biological requirements and place in crop rotation

Peas are successfully cultivated in a wide variety of climatic zones — up to the northern borders of agriculture at 68° N (Arkhangelsk Region, Yakutia, Kamchatka). Growing season of the crop ranges from 70 to 140 days depending on the cultivar and weather conditions. Peas rapidly accumulate vegetative mass with a relatively weak root system, which determines their high demand for moisture and soil fertility.

• Seed germination temperature — 1–2 °C (wrinkled and sugar peas: 4–6 °C)
• Cold hardiness of field pea seedlings — down to −8…−12 °C
• Critical frost for immature pods — −2…−3 °C
• Vernalization stage — 10–20 days at 2–8 °C
• Water consumption during seed swelling — about 110 % of their weight

Field pea cultivars, when sown in winter, are capable of overwintering in mild winters in the Transcaucasus and Central Asia. In more northern regions, their seedlings withstand significant spring frosts, however, during the fruiting period, immature pea pods are damaged even by light frosts. Flowering of the crop lasts from 10 to 40 days; the flowers are predominantly self-pollinating, but in dry and hot weather, cross-pollination is possible.

For growing peas, sufficiently moist, lime-rich chernozems of medium texture are best suited. Dense heavy clays and light sandy soils are unsuitable for it — in such areas, it is more advisable to sow field peas. In crop rotation, the crop is placed between non-legume predecessors, with the exception of oats and flax.

The best predecessors for peas are considered to be winter crops or row crops (potatoes, corn, sugar beet, millet), for which manure and mineral fertilizers were applied. Early-ripening cultivars are often used as fallow-occupying crops for winter cereals. Peas themselves leave behind clean fields and accumulated nitrogen, which has a positive effect on the yield of subsequent crops (corn, spring cereals, and industrial crops) for 1–2, and sometimes 4 years.

Nutrition, tillage and preparation for sowing

The tillage system">The tillage system for peas is practically identical to the standard preparation for early spring cereals. The crop responds excellently to deep autumn ploughing. Since emergence is strongly suppressed by weeds, the field must be as clean as possible, so peas are sown after predecessors that leave the arable land free from weeds.

Peas are calciphiles and prefer slightly acidic and neutral soils. The crop effectively assimilates poorly soluble phosphorus, so rock phosphate is an effective fertilizer for it rock phosphate. Potash and complete mineral mixtures (NPK) provide maximum effect on light sandy soils. On sod-podzolic soils, yield is increased by microfertilizers: manganese, boron (enhances the effect of liming), and molybdenum, which activates the reproduction of nodule bacteria and their nitrogen-fixing capacity.

The crop requires the earliest possible sowing date at a soil temperature of 4–5 °С, even before the mass sowing of spring cereals. An early start allows the seedlings to optimally pass through the vernalization stage due to spring temperatures. Tight sowing schedules help protect the crops from dangerous pathogens and pests.

1. No later than two weeks before sowing, carry out seed treatment with TMTD (tetramethylthiuram disulfide), Granosan, Derosal, Fundazol, Vincit, Benomyl, or Dividend preparations. Ensure that the preparation covers the seeds uniformly and that their moisture content after treatment does not exceed 14 %.
2. On the day of sowing, treat the seed material with preparations based on strains of root nodule bacteria (Sapronit, Rhizobacterin, or Nitragin).
3. Observe the inoculant dosage during treatment — 150–200 g of the preparation per 1 centner of seeds.

Before sowing, seed material is checked for field pea admixture by taking four samples of 100 seeds each. You can quickly distinguish field peas from garden peas using chemical or luminescent methods. For the chemical test, the seeds are soaked in water for 3 hours or boiled for 20 minutes, after which they are placed in a 1 % solution of potassium dichromate or a 5 % solution of sodium hydroxide. After 5 minutes, the seeds or hila of the field pea turn dark (dark brown or black), while the garden pea does not change color. With the luminescent method, the seeds are illuminated with an ultraviolet mercury-quartz lamp equipped with UFS-3 or UFS-4 light filters: garden peas produce a bluish or pink glow with a violet hue, while field peas glow brown.

Peas are sown using continuous row or narrow-row methods. Wide-row and strip sowing usually result in lower yield, are more prone to lodging, and are more susceptible to fungal diseases, which significantly complicates harvesting. On light soils, when sowing into a dried-out top layer, the seeding depth of the seeds seeding depth is increased.

• Sowing rate — 1 million viable seed per 1 ha (100 pcs./m²)
• Weight sowing rate — 120–400 kg/ha
• Seed depth — 6–8 cm
• Sowing depth on light, dry soil — up to 10 cm
• Row spacing for narrow-row sowing — 7.5 cm

Crop care begins with rolling, which enhances the moisture flow from the lower soil layers. If a soil crust forms and to control weeds, the field is harrowed across the sowing direction. Harrowing after emergence must be performed during daylight hours, when plants lose turgor and break less. This practice reduces annual weed infestation by up to 60%. To control quackgrass and other hard-to-eradicate weeds, crops are treated with the herbicide Fusilade Super or similar products.

Plant protection against pests and harvesting

During the emergence phase, pea crops can be severely damaged by pea leaf weevils. In the event of mass emergence, crops are sprayed with the insecticides Voloton, Anometrin, or Rovikur. During the period from budding to the beginning of flowering, plants are protected against a complex of pests: pea aphid, pea seed beetle, and pea moth. A biological method is effective against the pea moth — the release of Trichogramma at a rate of 50,000 individuals per hectare in two stages. To control the pea seed beetle, crops are dusted with 1–2% insecticides during the budding and flowering phases.

Peas ripen unevenly, so mowing begins when the lower and middle pods turn yellow. You cannot wait for the upper tier to ripen: the lower pods will crack, and the farm will lose the largest and most valuable seed. To accelerate the ripening of seed crops in wet weather, chemical drying of the plants in the field is performed — desiccation. For this, the defoliants Reglone or Roundup are used.

1. Mowing of plants into windrows.
2. Threshing of windrows using a self-propelled combine equipped with a pickup attachment.