Economic importance and agrotechnical features of lupine cultivation

Alkaloid-free (up to 0.0025% alkaloids) and low-alkaloid (up to 0.2%) cultivars have reduced resistance to adverse weather. They are more severely affected by Fusarium wilt, bacterial diseases, and aphids compared to bitter lupins.

The "budding — flowering — fruit set" phases are a critical period for moisture. Water deficit at this time leads to a 3–4 fold reduction in yield. Also critical is a drop in temperature below 14 °C during seed filling — under such conditions, maturation completely stops.

Different types of lupine have their own requirements for the thermal regime and acidity of the soil solution, which determines the choice of a specific type according to the soil and climatic conditions of the farm.

Characteristics of lupine types and cultivar composition

The genus Lupinus L. includes about 200 species. Agricultural production utilizes three annual species of Mediterranean origin and one perennial species native to North America. They all form a robust tap root system and an erect, pubescent shoot. Plant height varies from 60–80 cm for early-maturing forms to 1–2 m for late-maturing, highly branched cultivars.

The crops differ in pollination type and fruit morphology. Annual species are self-pollinators, whereas perennial lupine is a cross-pollinated plant. Lupine seed is large, flattened, and white or cream in color. In white, changeable, and modern yellow lupine cultivars, the pods are resistant to shattering, which significantly reduces losses during harvesting.

When selecting a lupine type for cultivation, one should be guided by their productivity and technological features:

• Perennial (multi-leaf) lupine: withstands harsh climatic conditions (matures up to the Arctic Circle), grows in one place for 8–10 years with a productivity peak in the 3rd year. In northern regions, it provides 2 cuts, in southern regions — 3–4 cuts. The yield of green mass is 210–300 centners/ha or more, and seeds — about 10 centners/ha. Prefers loams and sandy loams. Used for feed, green manure, and also for stabilizing eroding ravines. Although wild forms are high in alkaloids, modern cultivars have a low alkaloid content.
• Narrow-leaf lupine (blue): the most common annual type due to its lower heat requirements. Provides a green mass yield of 200–250 centners/ha (up to 500 centners/ha under favorable conditions), and a seed yield of over 20 centners/ha.
• Yellow lupine: a low-growing type with fragrant flowers, matures later than the blue one. Cultivars are sensitive to anthracnose, therefore they are cultivated in small volumes in southern regions and are also actively used in breeding work.
• White lupine: a heat-loving type reaching up to 1.5 m in height. In temperate climates, it is successfully cultivated in southern zones (in particular, in Polesia).

The following cultivars are recommended for practical field use:

• Narrow-leaf (blue): Ashchadny, Gulliver, Mirtan, Mitan, Mikhal, Pershatsvet, Pryvabny, Praleska, Khvalko, Vladlen.
• Yellow: Vayko belosemyanny, Bystrorastushchy 4, Nosovsky belosemyanny, BSKhA 382, BSKhA, Kastrychnik, Krok, Pava, Yulita.
• White: Snezhinka.

Choosing the correct predecessor for annual lupine is the basis for a healthy stand. It is best to place the crop after winter cereals, corn, or sugar beet. Sowing after spring cereals is allowed, but it is strictly forbidden to sow lupine after any grain legumes and perennial legumes. This will prevent the accumulation of Fusarium pathogens in the soil. Returning the crop to the same field is possible no earlier than in 4–5 years, and for cultivars sensitive to Fusarium, this interval should be 7–8 years.

For seed crops, avoid lowlands and waterlogged areas. Under such conditions, lupine actively increases vegetative mass, which delays the growing season and seed ripening. The soil for the crop is prepared in the same way as for peas. In this case, liming is carried out strictly 2–3 years before sowing lupine, under the preceding crops of the crop rotation. Due to its powerful root system, lupine effectively absorbs poorly soluble phosphates and potassium from deep soil layers, and also utilizes the residual effect of previously applied fertilizer.

Lupine requires extremely early sowing to maximize the use of spring soil moisture reserves. Its seedlings withstand frosts down to –6 °C, which allows entering the field at the earliest possible dates. Sowing depth of seed is 3–4 cm. When grown for green mass and silage, standard row sowing is used with the application rate increased by 10–15%.

• Frost resistance of seedlings — down to –6 °С
• Seed placement depth — 3–4 cm
• Increase in sowing rate for silage — by 10–15 %

For seed production, standard row or narrow-row sowing with row spacing of 7.5 and 15 cm is used, as well as the wide-row method with row spacing of 45 cm. For yellow and white lupin, both options provide the same yield, but wide-row sowing allows for mechanical inter-row cultivation.

Crop protection and harvesting specifics for lupin

Mechanical control of weeds requires care. To clean the fields, two successive harrowing operations are carried out, guided by the developmental stages of the plants. However, remember that due to shallow seed placement, there is a risk of damaging the sprouts and pulling them to the soil surface.

1. Pre-emergence harrowing is carried out 3–4 days after sowing.
2. Post-emergence harrowing is performed at the 3–4 pair of true leaves stage of the crop.

Pest and disease monitoring is conducted based on symptoms and key developmental stages. At the first signs of anthracnose, crops are treated with fungicides, such as Impact or Bavistin. If the weather remains humid and warm, the treatment is repeated after 10–12 days. To control sucking pests, in particular aphids and thrips, crops must be sprayed with insecticides of the Decis or Rogor type during the lupin budding stage.