ONION SEED PRODUCTION TECHNOLOGY IN PAKISTAN

 

Introduction:

Pakistan has a highly diversified topography and climate. The diversity of climate allows the cultivation of a wide range of temperate, tropical and subtropical crops of vegetables in the country. Therefore, the vegetable sector has the greatest potential of growth in the country.

Vegetables are the integral part of the cropping pattern of the country. But out of 20 millions ha cropped area, vegetables occupy only 2 %. The vegetables production is almost static on farm level due to the use of inferior quality seed coupled with other natural hazards like pests and diseases. Pakistan is a high potential area for vegetable culture because of varied agro-climatic conditions. Besides normal season, off-season production is also in vogue at higher altitudes in the mountains and frost-free areas and frosty areas in winter season under low-plastic tunnels in the plains.

Most of the seed requirements are met through imports from Japan, USA, European countries, China, Thailand and India. Vegetables seed is also produced in the country. But the reported quantity is negligibly low.

In vegetables development seed plays a vital role. Currently, availability of vegetable seed is not a constraint itself but availability of good quality seed of vegetable crop species is almost difficult in the country in a quantity, which can meet the requirements of farmers.

Seed production technology:

Onion seed production is the most sensitive job. In seed production, selection of bulbs of the appropriate size is a process, which has direct bearing on seed yield, crop uniformity and cost of production. The cost of production is the most important factor for the seed producer. The use of large size bulbs increases bulb-planting rate per hectare while medium size bulb selection reduces the bulb rate to almost half, which consequently cuts the cost of production. The single largest component in the cost of seed production is the cost of selected mother bulbs. Large size bulbs are prone to disease attack in the store, hence for practical reasons, medium size bulbs as usually recommended for seed production. Medium sized bulbs are, weighing 100-150 (4-6 cm size) grams, the most favored size for seed production.

The bulbs are planted in the pre-prepared field in the month of October. Before planting, bulbs are once again sorted out strictly according to the standard criterion for the variety. The top of the bulb is cut one third of the way down to accelerate sprouting in the field and recognizing and sorting out the internally doubled bulbs. The bulbs are put for 5 minutes into a solution containing fungicide, mostly Dithane M45. The bulbs are then taken out and spread in the sun to dry out before being planted. They are planted on top of the ridges with 75 cm space between the rows and 30 cm between the plants. After sprouting in the field, herbicide is sprayed to inhibit the weeds.

As it grows, the vegetative portion of the plant is cut in order to suppress the growth of early seed stalking and to encourage more seed stalks to grow. A 2-3 cm green portion is left with the basal stalks, which are mostly white in color. This practice is started from the end of January and goes on till the mid-February. During this stage, the process of weeding and hoeing is started. The remaining nitrogen is applied and earthing-up is done. The crop is then sprayed with a mixture of fungicide (Dithane M45 @ 2.5 gm) and insecticide Timaron @ 2.5 ml/litre of water).

In order to achieve the standards fixed by the Federal Seed Certification and Registration Department (FSCRD), Ministry of Agriculture Livestock and Cooperatives, Islamabad, Pakistan for quality seed production, a maximum isolation distance of 1600 meters is ensured to avoid cross pollination among different varieties. However, high standard and uniformity cannot be achieved through ensuring isolation only. A severe rouging, 30-35%, is also done in the presence of an FSCRD representative.

Harvesting and packing of onion seed is a sensitive stage. As the crop reaches its harvesting stage, the umbel/flower turns brown and the seed bud gets open a little bit where the seed is clearly seen. That is the right stage for harvesting. Onion seed is harvested in succession. As the signs appear, the process of harvesting the crop should immediately be started. The harvested flowers are spread in the sun on a tarpaulin for drying. As the stuff gets dried, it should be crushed with small sticks slowly to avoid damage to the seed. Then it is cleaned with sieves using a pedestal fan for providing air to blow away the dust. After cleaning, the seed is put in the sun for 2-3 hours to dry it further. It is packed in the cloth bags according to the market needs.