Lecture - 17 Origin, History and Cultivation of Onion

Origin, History and Cultivation of Onion:-

Origin of Onion:-

Scientific Name:- Allium cepa L.

Family:- Amaryllidaceae (earlier: Alliaceae)

Chromosome Number:- 2n = 2x = 16

Center of Origin:-

> The primary center of origin of onion is believed to be Central Asia, particularly Iran, Pakistan, and the western Himalayas.

> Some researchers suggest Turkmenistan and Uzbekistan as places of domestication.

> It is one of the oldest cultivated vegetables, grown for over 5000 years.

History of Onion:-

Ancient Egypt:-

> Onions were revered and used in mummification rituals.

> Images of onions appear in tombs; they symbolized eternity due to their concentric layers.

India:-

> Mentioned in ancient Sanskrit texts and used both in food and medicine.

Greece & Rome:-

> Greek athletes consumed onions for strength.

> Roman gladiators rubbed onions on muscles for firmness.

China:-

> Cultivated for thousands of years and used in traditional medicine.

Europe:-

> Introduced by Romans and became a staple during the Middle Ages.

Americas:-

> Brought by European settlers in the 15th and 16th centuries.

> Native wild onion species were already used by indigenous peoples.

Cultivation of Onion:-

i. Climatic Requirements:-

Season:- Cool and dry season is ideal.

Temperature:-

Germination:- 20–25°C

Bulb development:- 12–24°C

> Excessive rain or high temperatures reduce bulb quality.

ii. Soil Requirements:-

> Well-drained loamy or sandy loam soils with high organic matter.

pH:- 6.0–7.0 (slightly acidic to neutral).

> Sensitive to waterlogging and salinity.

iii. Land Preparation:-

> Plough the field 3–4 times to a fine tilth.

> Incorporate well-decomposed FYM or compost (20–25 tons/ha).

iv. Sowing Time (India-specific):-

Rabi (main season):- October to December

Kharif season:- May to July

Late Kharif:- August to September

v. Propagation:-

> Mainly by seeds or transplanting seedlings.

Seed rate:- 8–10 kg/ha for transplanting.

vi. Spacing:-

Row-to-row:- 15–20 cm

Plant-to-plant:- 7–10 cm

vii. Irrigation:-

> Light and frequent irrigations are required.

Critical stages:- bulb formation and enlargement.

viii. Nutrient Management:-

Basal dose:- FYM + NPK (60:40:40 kg/ha)

> Apply nitrogen in 2–3 split doses.

ix. Weed Management:-

> Manual weeding or use of herbicides (like pendimethalin) is effective.

> Mulching helps conserve moisture and control weeds.

x. Pest & Disease Management:-

Common Pests:- Thrips, onion fly

Common Diseases:- Purple blotch, downy mildew, basal rot

> Use of resistant varieties and proper crop rotation helps control.

xi. Harvesting:-

> Done when 50–70% tops fall over and necks soften.

> Harvest carefully to avoid bruising.

xii. Post-Harvest Handling:-

> Cure bulbs in the field for 7–10 days under shade.

> Store in well-ventilated structures at 25–30°C and low humidity.