Cultivation of French bean

Botanical Classification:

• Scientific Name: Phaseolus vulgaris
• Family: Fabaceae
• Genus: Phaseolus
• Common Names: French Bean, Green Bean, Snap Bean, Runner Bean, String Bean

Nutritional Composition (per 100g serving):

• Calories: 31 kcal
• Protein: 2.4 g
• Carbohydrates: 7.1 g
• Fiber: 3.4 g
• Fat: 0.1 g
• Vitamin C: 12.2 mg (20% of daily recommended value)
• Calcium: 37 mg
• Iron: 1.0 mg
• Potassium: 211 mg

Origin of French Bean (Phaseolus vulgaris)

• Native Region: Southern Mexico and Central America are considered the primary regions where French bean (common bean) originated. The crop was domesticated from wild varieties that are believed to have grown in these areas.
• Spread to Other Regions: After its domestication, French beans spread across the globe, and today they are cultivated widely across Asia, Africa, and Europe.
• Significance in Agriculture: It is one of the most widely consumed vegetables globally, especially valued for its nutritional value (high protein, fiber, vitamins, and minerals).

Area of Cultivation

• Global Cultivation: French beans are grown in both tropical and temperate climates. They are grown in a variety of regions worldwide, including parts of Africa, South America, Asia, and Australia.
• India’s Major Growing Areas: French beans are primarily cultivated in North Indian states like Uttar Pradesh, Madhya Pradesh, Himachal Pradesh, and Karnataka. They also grow well in hilly areas and are cultivated in regions like the Chhotanagpur Plateau and the hills of Himachal Pradesh.

Climate

• Optimum Temperature: French beans thrive in cool climates with an optimum temperature range of 15°C to 25°C. Higher temperatures above 30°C can negatively affect flowering and pod development.
• Tolerant to Short Periods of Low Temperatures: French beans are relatively tolerant to cold and will endure light frost during early growth stages, but they are sensitive to frost during flowering and pod formation.
• Rainfall Requirements: The ideal rainfall is around 500-750 mm/year, distributed evenly throughout the growing period. Excessive rainfall can lead to root rot and pod damage.
• Day Length Sensitivity: French beans are generally day-neutral, although some pole varieties may have short-day requirements.

Soil Requirements

• Soil Type: French beans grow best in well-drained light sandy loam or loamy soils with a good water retention capacity. Heavy, clayey, or waterlogged soils are unsuitable due to the risk of root rot and poor aeration.
• Soil pH: The optimal pH range for French beans is 5.5 to 6.5. Highly acidic or alkaline soils are not suitable.
• Fertility: The soil should be rich in organic matter to support root growth and nutrient uptake. Well-decomposed compost or farmyard manure (FYM) is often applied to improve soil fertility.

Improved Varieties of French Beans

French beans are available in different varieties based on growth habit (bush or pole) and fiber content (stringless or stringed).

1. Pole Varieties (climbing beans):
   • Kentucky Wonder: Known for long, flat pods, with excellent flavor and texture. It has high yield potential, around 12-15 tons/ha.
   • Arka Shweta: A pole-type variety with high disease resistance and yields of 12-14 tons/ha.
   • YED 1: Resilient and suited for high-altitude cultivation. Yields around 8-10 tons/ha.
2. Bush Varieties (compact growth):
   • Pusa Parvati: Early-maturing, stringless variety with resistance to powdery mildew and mosaic. Yields about 9-10 tons/ha.
   • Contender: High-yielding, stringless pods that mature in about 50-60 days. Yields range from 8-9 tons/ha.

Cultivation Practices

Seed Rate and Planting Techniques

• Bush Varieties: Plant at 80-90 kg/ha for optimal seed rate.
• Pole Varieties: The seed rate is lower, around 30-40 kg/ha, due to their vertical growth habit.
• Sowing Method: French beans are generally directly sown as seeds in the soil. For better germination, the soil should be well-prepared, with good drainage. Furrow sowing and broadcast sowing are common methods.
• Spacing:
  • Bush Type: 45 cm x 15 cm.
  • Pole Type: 90 cm x 10-15 cm to allow for climbing and proper spacing between plants.

Time of Sowing

• Plains of India: Sowing is typically done from July to September for the kharif season. In spring, sowing may take place between January to March.
• Hilly Areas: Sowing may be delayed and done from March to May due to lower temperatures.

Transplanting While French beans are generally direct sown, in regions with heavy rainfall, nursery sowing can be done, and seedlings are transplanted into the field after the first 3-4 true leaves appear.

Fertilizer Requirements

• Apply FYM at 200-250 q/ha at the time of land preparation.
• Fertilizer recommendations:
  • N: 30-50 kg/ha.
  • P₂O₅: 60-100 kg/ha.
  • K₂O: 30-60 kg/ha.
• French beans respond positively to phosphorus and potassium fertilizers, especially in soils deficient in these nutrients.

Irrigation

• French beans are susceptible to water stress and require regular irrigation, particularly during flowering and pod development. Over-irrigation, however, can lead to root rot.
• Irrigation is required at the following intervals:
  • Pre-flowering: Keep the soil moist but not waterlogged.
  • Post-flowering: Ensure consistent moisture during pod development.
• The crop requires about 300-350 mm of water during its growing period.

Weed Management

• Pre-sowing: Use herbicides like Fluchloralin (2-3 liters per hectare) to control weeds.
• Weed Control: Regular hand weeding is necessary, especially in the first 4-6 weeks of growth. Shallow cultivation can help in weed suppression.
• Mulching: Applying organic mulches (straw, grass) helps in moisture retention and weed suppression.

Harvesting

• Maturity Time: French beans are ready for harvest in about 45-70 days from sowing, depending on the variety and environmental conditions.
• First Harvest: Pods should be picked when they are immature and tender.
• Subsequent Harvests: For pole varieties, harvest the pods in multiple picks (every 7-10 days) as they mature at different rates.

Yield

• Bush varieties: Yield around 8-10 tons/ha.
• Pole varieties: Higher yield potential, about 12-15 tons/ha.
• The total yield depends on soil health, climate conditions, and management practices.

Physiological Disorders

French beans are prone to certain physiological disorders that can impact the yield and quality of the crop:

1. Transverse Cotyledon Cracking: This occurs when dried seeds are planted in wet soil, leading to mechanical damage to the seed coat and reduced germination.
2. Pod Development Problems: Moisture stress or nutrient deficiencies (like calcium and magnesium) can result in pod abortion or poor pod filling.
3. Yellowing and Wilt: Due to root rot, especially in poorly drained soils, plants exhibit wilting and yellowing of leaves.

Diseases and Pest Management

• Diseases:
  • Powdery Mildew: Caused by the fungus Erysiphe polygoni. Use resistant varieties and fungicide sprays like Carbendazim.
  • Rust: Caused by Uromyces appendiculatus. Proper irrigation and crop rotation are helpful in managing this disease.
  • Bacterial Blight: Caused by Pseudomonas syringae, which can be controlled by avoiding overhead irrigation and using resistant varieties.

Pests: Aphids, whiteflies, and leafhoppers are common pests that infest French beans. Use appropriate insecticides and biological control (like ladybugs) for pest management.