Onion belongs to the family Amaryllidaceae with botanical name Allium cepa. Areawise India ranks second while production wise it ranks third among the total onion production in the world. In the world total area under cultivation of onion is about 19,77,000 hectare which gives 2,79,18,000 mt. Major producing countries are North America, Japan, Spain, Netherland, Canada, etc. while in India it is grown in Gujarat, Punjab, Haryana. Area under cultivation in Maharashtra is about 54,600 hectare.

Climate and Soil:

An ideal soil should have pH in between 6.5 to 8. The soil should be well aerated. Heavy soil should be avoided. It is grown under a wide range of climatic conditions. However, it cannot stand too hot or too cold weather. It prefers moderate temperature in summer as well as in winter. Short days are very favorable for the formation of bulbs. It can be grown well at elevations of 1000 to 1300 m above MSL. Onion requires well drained loamy soils, rich in humus, with fairly good content of potash. The crop raised on sandy or loose soil does soils, the bulbs produced are deformed and during harvesting, many bulbs are broken and bruised and so they do not keep well in storage.

Pusa Red, Pusa Ratnar, Pusa White Round, Patna Red, Poona Red, Arka Pragati, Arka Niketa, Patna White, Bombay White, Nasik Red.

It is grow as an annual or biennial. The smooth, glaucous scope grows from 1 to 3 feet high. The scope or stem is hollow and swollen above the base. The leaves are also swollen at base and hollow. Flowers, terminal, umbel, white or faint blue, numerous, develop bulbels. Underground bulb undeveloped like the stem. Propagation by Bulbels.

Onion belong to bulb vegetables group. Onion seeds are sown in nursery from October to November. In south and eastern India from September to October. In hills from March to June. One hectare needs 8-10 kg seeds. Seedlings are transplanted in December and January. Early transplanting yields more. Bulb and bulb-lets are also sown but needs 1000-1200 kg. / hectare.

The seed of onion in the nursery from middle of October to the end of November. In the hills, the seed is sown from March to June. Planting distance for Onion (seedlings) is 15 X 10 or 20 X 10cm

Onion F.Y.M. 200-250 g/hectare
45-65 Kg N/hectare
40-60 kg P/hectare
60-100 kg K/hectare

Irrigation during growth should be steady and uninterrupted otherwise dryness may cause splitting of the outer scales. Irrigation is stopped when the tops mature and start falling. Use F1 hybrids for higher yield.

Onion
Pest

• Thrips- Spray Malathion or Nuvacron (0.1%)
• Borer- Spray Endosulfan (0.1%)
• Maggot- Apply Thimet 10G to soil and spray Malathion (0.05%)

Diseases

• Downy mildew- Spray Difolatan (0.1%) or Dithane M-45 (0.2%)
• Smut - Spray Captan, Biltox or Thiram 75%

Onion gives a yield of 25 to 30 tones/hectare and garlic about 6 to 10 tonnes. Bulbs should be thoroughly cured before storage.

In case of onion crop there are various factors affecting the storing conditions. Some important are listed below.

1. Selection of Variety

2. Fertilizers and water management

3. Drying of onion

4. Actual storage conditions

5. Construction of storage structure

1. Selection of Variety: In majority of the cases onion crop grown in rabi season are stored. This can be stored for about 4 to 5 months. In case of storage selection of variety is an important aspect where N 2-4-1, Agrifound light red, Arka niketan were found to be suitable one giving less percentage of losses.

2. Fertilizers and water management: Doses of fertilizers, type of fertilizers and irrigation affects the storing capacity of onion / shelf life of onion. Organic matter increases the storing capacity of onion. Rate of fertilizer suggested is 150:50:50, N:P:K kg per hectare respectably. In case of irrigation according to soil tag crop should be irrigated.

3. Drying of onion: Immediately after harvest let the onion should get dried for about 8 to 10 days which helps to remove the excess heat giving better colour to onion.

4. Actual storage conditions: In case of storage condition temperature and humidity are the important parameters. Optimum temperature ranges from 25 to 30 ⁰C and RH 65 to 70%. Excess humidity and temperature results in fungal growth. On the contrary decrease in humidity increases respiration rate causing weight loss. In May-June temperature is more and relative humidity is less which affects the weight loss. While in case of July-September temperature goes down resulting in sprouting of onion. To avoid these problems construction of proper storage structure is required.

5. Construction of storage structure:

i Storage structure should be constructed 30cm from the ground level giving cement base which avoids contact with soil moisture.

i For roofing purpose sugarcane trash, asbestos sheet is used which lowers down the temperature.

• For good aeration central height should be optimum (120cm) giving sloppy

structure

i Care should be taken that the stored onions should not get directly expose to sunlight which gives good colour and improves the structure of onion. 1ft³ area can store 20kg of onion.

• Before and after storage stabilization of the storage structure can be done by spraying 10g

• Bavistin + 15ml neuocron in 10 liters of water which helps in controlling the pest.

Minimum Rs.20,000 to 25,000 for the above mentioned structure.