Economic importance and agricultural practices for bean cultivation

Economic importance of beans and cultivar selection

The bean is a valuable food and row crop with high yield potential. In terms of protein content, it is close to peas, while in taste and cookability, it surpasses most grain legumes. Bean seeds contain valuable amino acids (tyrosine, tryptophan, lysine) and are widely used in the canning industry; adding 5–10% flour from white-seeded cultivars improves the nutritional value of wheat bread.

In crop rotation, beans serve as an excellent precursor for maize, spring cereals, and other crops. They are often grown in mixed crops with maize, potatoes, and cucurbits. For example, joint cultivation of maize and beans in Georgia on an area of over 150 thousand hectares makes it possible to obtain more grain of both crops than when grown separately. Despite the opinion about low bean yield, data from experimental stations and advanced practice show the possibility of obtaining high grain harvests.

• Yield potential — above 25–28 c/ha
• Vernalization temperature — from 10 to 20 °C
• Growing season — from 75–80 to 120 days

The main part of bean crops in the CIS is concentrated in the North Caucasian republics, Krasnodar and Stavropol Territories of Russia, in Ukraine and Moldova. Over time, cultivation areas have moved north up to the latitude of St. Petersburg. As a vegetable crop, early bean cultivars are successfully spreading in the Moscow region, Belarus, and Western Siberia.

In Belarus, zoned seed and vegetable bean cultivars are grown. They are well adapted to local climatic conditions and ensure a stable harvest. Depending on production goals, agronomists choose cultivars for specific purposes:

• Seed cultivars: Belorusskaya 288, Motylskaya belaya, Krasnogradskaya, Rychi, Triumf, Shchedraya;
• Vegetable (green bean) cultivars: Zinulya, Irishka, Karson, Laurina, Mirobela, Olga, Tara.

Biological features and requirements for growing conditions

The common bean originates from the New World, where it was established as a crop 3–4 thousand years BC under the conditions of dry farming in the South Mexican and Guatemalan plateaus, as well as Peru. It does not occur in the wild, and one of its parental hybrid forms could have been Phaseolus aboregineus or Phaseolus macrolepis species. American beans reached Europe after the discovery of the continent, spreading first in botanical gardens, and since the 17th–18th centuries — in kitchen gardens and fields.

There is also an independent Asian center of origin for small-seeded beans, where they were grown 5–6 thousand years ago. The crop began to spread to the territory of the European part of Russia and Belarus from Europe in the late 17th — early 18th century. In Georgia, the bean attained the status of a national crop as early as the 17th century.

Among all species, the common bean is the least demanding in terms of heat. It belongs to light-loving short-day crops, although there are individual long-day cultivars. The crop is more drought-resistant compared to peas, lentils, and broad beans; however, a moisture deficit can lead to the shedding of buds and flowers. The duration of flowering for bush cultivars is 15–20 days, while climbing forms bloom from 30 to 50 days.

The stage of vernalization in beans is very short and takes place at a temperature from 10 to 20 °C. To complete the light stage, plants require short days combined with elevated temperatures. Common beans are mainly self-pollinating, although cross-pollination by insects is possible, while the runner bean is an obligate cross-pollinator.

In addition to food use, bean leaves serve as raw material for the production of citric acid. The crop is also used in herbal medicine and as green manure. For decorative purposes, runner beans are often planted in gardens.

There are 20 known species of beans in cultivation. They are divided into two main groups based on origin and botanical characteristics:

Characteristics of the main bean types and groups

In agricultural production, bean types are divided into two geographical groups: American and Asian. The choice of a specific type determines the requirements for heat, moisture supply, and technical characteristics of the seed at harvesting. Key features of the cultivated bean types are listed below.

Bean cultivation: crop rotation, fertilizer, and sowing

Beans are grown as a typical row crop. To obtain high yields, light chernozems or fertile loamy soils with mandatory liming are allocated for sowing. When planning the crop rotation, it is important to select appropriate predecessors to prevent common diseases.

To protect the crops from pathogens and stimulate plant development, mandatory pre-sowing seed treatment is carried out. The complex of measures includes air-thermal heating of the seed material before sowing, seed treatment with fungicides, and application of a nitragin preparation. These practices help reduce the infection background during the early stages of the growing season.

The fertilizer system necessarily includes basic phosphorus-potassium fertilizers and starter nitrogen doses. Phosphorus-potassium fertilizers are applied at a rate of 50–90 and 40–60 kg of active ingredient per hectare. Nitrogen fertilizers should be applied before pre-sowing tillage.

• Soil temperature for sowing — 12–14 °С
• Seed sowing depth — 5–6 cm (up to 8 cm)
• Nitrogen fertilizers under tillage — 10–25 kg of active ingredient/ha
• Seed application rate — from 80 to 120–150 kg/ha
• Sowing density — 0.3–0.4 million seeds/ha
• Row spacing — 45–60 cm

Sowing is carried out by row or square-cluster methods after the threat of frost has passed. Do not sow beans in cold soil: in unheated soil, seeds do not germinate for a long time and are at risk of rotting. This allows for uniform emergence and maintaining the plant stand density.

The harvest time for beans is determined by the yellowing of most pods and the hardening of the seeds within them. If left in the field too long, the pods of many cultivars shatter and seeds are lost. It is best to harvest beans early in the morning, while there is still dew. Combine harvesters with low-cutting attachments can be used for harvesting. Beans must be threshed with caution to prevent seed splitting; special bean threshers are best. After picking the green pods, the stems and leaves of the bean plants can be ploughed under as green manure or ensiled in a mixture with other feed.