🥜 Groundnut

Oil Percentage of Oilseed Crops

• World (Production): Soybean > Cotton Seed Oil > Rapeseed Oil > Groundnut > Sunflower
• India (Production): Soybean > Groundnut > Rape Seed and Mustard
• Generally, Sulphur and Phosphorus are required in higher amount in Oilseed crops than other crops. ^{IBPS 2018}

Groundnut

• Botanical name: Arachis hypogea
• Arachis hypogea fastigate (Bunch/Erect /Spanish type)
• Arachis hypogea procumbens (Spreading/Verginia runner type)
• Family: Papilionaceae
• Origin: Brazil
• Area: India > China > Nigeria
• Production: China (36%) > India (17%) > Nigeria
• Productivity: USA
• Groundnut is also called as Peanut, Monkeynut, Earthnut and Mungfalli. Poor Man’s Almonds.
• Chromosome No: 2n = 40
• King of Oilseed (Queen -> Sesame)
• Arachis hypogea word is derived from two Greek words:
  • Arachis means Legume
  • Hypogea means Below the ground or soil

Climate

• Groundnut is wide spectrum adoptable crop which grown in all 3 seasons.
• It requires tropical climate.
• It requires an average annual rainfall of 500-1000 mm.
• Best suited temperature for crop growth is between 25-35 °C.
• Flowering and seed setting affected by cloudy weather.
• It resists drought and tolerate flooding for one week once it establishes.
• Groundnut is a self-pollinated, C3 and short-day plant.

Soil

• Groundnut thrives best in well-drained sandy and sandy loam soils, as light soil help in easy penetration. (Black Soil)
• Clay soil is strictly avoided to grow groundnut because of presence of high moisture.
• Soil with pH between 6.0-6.5.

• Groundnut is a modified fruit.
• Fruit of groundnut is Nut and fruit type is Lomentum.

• Gynophore of groundnut is known as Peg (intercalary meristem from fertilized flower). Peg formed from fruits.
• Geotropism: At the base of ovary, a meristematic region grows and becomes a stalk like structure (gynophore) that bends downwards and forces the ovary into the soil. The peg (gynophore) carrying the ovary pushes itself into the soil. After entering the soil, ovary begins to develop and takes up to horizontal position and pods begins to enlarge.
• Flowering starts 24 to 40 days after sowing.
• Pegs become viable in 5-7 days after flowering and takes 2-10 days to insert into the soil.
• Testa is a thin skin that covers the seed or nut.
• Inflorescence: Raceme

  

• Ratio of: Flower : Pegs : Pods is 7 : 4 : 1.
• Groundnuts contain 45 % oil in kernel and 26 % protein in kernel.
• Groundnut cake contains 7-8 per cent nitrogen.
• Shelling percentage of groundnut is 70 per cent.
• Groundnut accounts more than 30 per cent acreage and 40 per cent of total oilseed production of India.
• Leading groundnut producing states are Gujarat > Tamil Nadu > Andhra Pradesh.
• The effects are:
  • Gynophores are swelled & shrinkage and quality affected.
  • Pod growth is affected due to soil compaction.
• At the time of sowing, 0.1 per cent Ethrel + 3 gm Thirum is used for seed treatment and to break seed dormancy.
• Generally, Groundnut grown during Rabi season gives higher yield as compared to Kharif season crops due to fewer incidences of insect and pests and diseases.

Sowing Time

• Kharif: 3rd week of June to 1st week of July
• Rabi: November
• Summer: Last week of Dec to end of January

Seed Rate

• Bunch type varieties: 100-120 kg/ha
• Spreading type varieties: 80-100 kg/ha
• Germination type: Hypogeal

Irrigation

• Kharif: no need
• Rabi: 5-6 irrigation
• Summer: 10-12 irrigation

Critical stages of crop growth:

1. Establishment (10-20 DAS)
2. Vegetative phase (25-35 DAS)
3. Flowering and peg initiation stage (35-50 DAS)
4. Pod formation stage (50-75 DAS)
5. Pod/Seed development stage (75-90 DAS)

Critical stages for irrigation:

1. Flowering stage
2. Pegging stage
3. Pod formation stage

• Check basin irrigation is most suitable irrigation method for groundnut.
• IW/CPE ratio of groundnut is 0.6.
• During pod development stage, field should be well drained, otherwise due to the poor aeration, the formation of toxin (Aflatoxin) takes place.
• Application of 25 : 60 : 60 kg NPK/ha with 25 to 50 kg ZnSO4 and FeSO4 both give higher yield of groundnut.
• Intercultural operations should be avoided during pegging stage.

• Star weeder is used to control weeds in groundnut fields.
• NAA @ 40 ppm is used to enhance floral initiation and pod formation.
• Calcium (Ca) is essential for pod development.

Bunch type and Spreading type

• Earthing-up is done in groundnut crop at 35 to 45 days after sowing to facilitate proper development of pegs beneath soil and increases number of seeds per pod.
• The most common groundnut based cropping systems are:
  • Groundnut + Pigeonpea (4:1)
  • Groundnut + Castor
  • Groundnut + Sunflower
  • Groundnut + Urdbean (4:1)
  • Groundnut + Til (3:1)

Yield

• Bunch Type: 15-20 q/ha
• Spreading Type: 20-30q/ha
• Strain used for biological N₂ fixation in groundnut is Rhizobium japonicum.
• Groundnut should be stored at 5 per cent moisture content.
• Bitterness of kernel is due to Aflatoxin (toxic substance) developed by two reasons:
  • When pod moisture content is > 8 per cent
  • Fungus namely Aspergillus niger and Aspergillus flavus. ^{FCI AGM 2021}

Disease

Insect-Pest