Cajanus cajan aka Pigeon Pea

Pigeon pea is remarkably easy to grow and requires minimal care. It is extremely drought-resistant once established and can thrive in areas with less than 650mm annual rainfall. The plant succeeds in nutritionally poor soils and tolerates light sandy, medium loamy, and heavy clay soil types, making it adaptable to various growing conditions. As a nitrogen-fixing legume, it actually improves soil fertility rather than depleting it, requiring minimal fertilizer inputs.

Pigeon pea prefers consistently moist soil during establishment but becomes extremely drought-resistant once mature. The plant thrives with 500-1,000mm of rainfall annually and can survive in areas receiving less than 650mm per year. In drought-prone regions, it serves as a reliable alternative crop where other plants fail. Water regularly during the seedling stage, then reduce watering as the plant matures and develops its extensive drought-tolerant root system.

Pigeon pea is remarkably adaptable and tolerates light sandy soils, medium loamy soils, and heavy clay soils. It prefers well-drained conditions but succeeds even in nutritionally poor soils. The optimal pH range is 5.5-6.5 (slightly acidic to neutral), though it can grow in acidic, neutral, and alkaline soils. As a nitrogen-fixing legume, the plant actually enriches the soil through symbiosis with Rhizobia bacteria, making it valuable in crop rotation systems and as green manure.

Pigeon pea requires full sun exposure and cannot tolerate shade. The plant thrives in bright, direct sunlight typical of tropical and subtropical regions. Its bright, nectar-rich flowers are adapted to attract pollinating insects in full sun conditions. For optimal growth and seed production, ensure the plant receives unobstructed sunlight throughout the day.

Pigeon pea thrives in warm tropical and subtropical climates with optimal temperatures between 20-30°C (68-86°F). The plant can tolerate temperatures up to 35°C (95°F) and is hardy in USDA zones 9-12 (UK zone 10). It is not frost-tolerant and requires year-round warm conditions to thrive as a perennial. In cooler climates, it can be grown as a warm-season annual during the frost-free period.

Pigeon pea is completely non-toxic and is widely cultivated as a major food crop worldwide. The seeds, young leaves, shoots, and seedpods are all edible and highly nutritious. The seeds are particularly rich in protein and essential amino acids including methionine, lysine, and tryptophan. The plant is safe for humans and livestock, with the seeds commonly consumed as dal in South Asian cuisine and used as fodder for animals.

Pigeon pea requires minimal fertilization due to its nitrogen-fixing capabilities. As a legume, it forms symbiotic relationships with Rhizobia bacteria in root nodules, which fix atmospheric nitrogen and actually enrich the soil. The plant can derive up to 79% of its nitrogen from the atmosphere. It succeeds in nutritionally poor soils and is often used as green manure to improve soil fertility for subsequent crops. If needed, a light application of phosphorus and potassium may benefit flowering and seed production, but nitrogen fertilizer is generally unnecessary.

Pigeon pea is propagated from seed, which can be sown directly in the field or started in containers. The plant supports both cross-pollination (averaging 20% via insect pollinators) and self-pollination, producing viable seeds readily. Short-duration varieties mature and produce seeds in 3-4 months, while traditional varieties require 5-11 months. Seeds should be planted in warm soil after the last frost in temperate climates, or year-round in tropical regions. Natural outcrossing can occur, so isolate different varieties if seed purity is desired.

Pigeon pea is an evergreen shrub that can reach 4 meters (13 feet) in both height and spread when grown as a perennial. The growth rate is moderate, with short-duration varieties maturing in 3-4 months and traditional varieties taking 5-11 months to first harvest. As a perennial, the plant can live 3-5 years, though seed yield drops considerably after the first two years. Modern dwarf varieties have been developed for easier machine harvesting, growing more compactly than traditional tall varieties.

Two main botanical varieties exist: Cajanus cajan var. flavus (early-maturing, moderately-sized, often grown as an annual) and var. bicolor (taller, late-maturing, perennial form). Modern plant breeding has developed numerous cultivars including short-duration varieties (3-4 months to maturity) for multiple cropping systems, disease-resistant varieties for Fusarium wilt and other pathogens, and dwarf varieties suitable for mechanical harvesting. India alone has many traditional landraces adapted to local conditions, reflecting the plant's genetic diversity.

Pigeon pea is exclusively grown outdoors as an agricultural field crop in tropical and subtropical regions. It is hardy in USDA zones 9-12 (UK zone 10) and requires frost-free conditions. The plant is widely cultivated across South Asia, Southeast Asia, Africa, Latin America, and the Caribbean. In marginal climates, it can be grown as a warm-season annual, sown after the last frost and harvested before the first frost. It thrives in rainfed agriculture systems and is particularly valuable in semiarid tropics with 500-1,000mm annual rainfall.

Pigeon pea is native to the Eastern Hemisphere with India considered its primary center of origin. Archaeological evidence dates its cultivation in peninsular India to at least 2,800 BCE, with finds from the 14th century BC at Neolithic sites in Bellary. A secondary center of genetic diversity exists in West Africa, where it likely arrived from India via trans-oceanic Bronze Age trade routes around 2,200 BCE (evidenced by seeds in Egyptian tombs). From Africa, it spread throughout the continent and was later introduced to the Americas via the trans-Atlantic slave trade in the 17th century.

Common insect pests include the gram pod borer (Helicoverpa armigera) causing defoliation and pod damage, blue butterfly (Lampides boeticus) infesting buds and flowers, spotted pod borer (Maruca vitrata) webbing pods, and tur pod bug (Clavigralla gibbosa) damaging seeds. Major diseases include Fusarium wilt (Fusarium udum), dry root rot (Macrophomina phaseolina), Phytophthora blight, Alternaria leaf spot, powdery mildew (Leveillula taurica), sterility mosaic virus, and yellow mosaic virus. Integrated pest management strategies including crop rotation, intercropping, biological controls, and disease-resistant varieties provide effective management.

Pigeon pea is highly edible and a major food crop worldwide. Very young seeds can be cooked and eaten like fresh peas in rice dishes. Mature seeds are dried and split to make dal (toor dal), a protein-rich staple in South Asian cuisine used in soups and stews. Young leaves and shoots serve as cooked vegetables, though they quickly become fibrous with age. The immature seedpods can be eaten as a vegetable. Seeds are particularly nutritious, containing high levels of protein and essential amino acids including methionine, lysine, and tryptophan, with mature seeds containing 21.7g protein per 100g.

Traditional medicine uses pigeon pea leaves as an infusion to treat pulmonary conditions such as coughs and bronchitis. Additional traditional applications include treatment of hemorrhages, diarrhea, wounds, diabetes, and sore throats. The plant contains bioactive compounds including flavones and cajanone, an antimicrobial agent. While these traditional uses are documented, the plant receives a moderate medicinal rating (2 out of 5) as it is primarily valued as a food crop rather than a medicinal herb.

Pigeon pea has extensive non-food applications valued at 4 out of 5. As a nitrogen-fixing legume, it serves as excellent green manure and soil enrichment, fixing up to 79% of its nitrogen from the atmosphere. The plant functions as a windbreak, soil stabilizer with its extensive root system, and living support for climbing crops. Stems are used in basketry and thatching. Dried stalks provide fuel with approximately half the heat value of coal. The plant is also valuable as fodder for livestock and serves in intercropping systems with cereals like sorghum, pearl millet, and maize.

Pigeon pea produces bright, nectar-rich flowers that are highly attractive to pollinating insects including bees and butterflies. The flowers support both cross-pollination (averaging about 20% depending on pollinator populations) and self-pollination. Flowering leads to pod formation containing the edible seeds. The exact bloom time varies by variety, with short-duration varieties flowering and setting seed within 3-4 months while traditional varieties take 5-11 months to reach flowering maturity.