Harvesting Technology Of Onion Large Plant Seed Production For Two Consecutive Years

By Author: doris zhang
Total Articles: 72
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Large plant seed production of onion is a seed production method adopted in most parts of China, but it is only a harvest. The onion seed production method discussed here uses the large bulb of onion to germinate 3-4 bulb buds and form 3-4 flower bolting. During the growth period of flower bolting, an independent small bulb can be formed at the base of flower bolting and contains 3-4 bulb buds, which germinate into 3-4 small bulbs in autumn, The number of bolting in the next year is 3-4 times that in the first year. Using it for the second seed production, the yield can also be doubled. The large plant seed production method of onion has been planted for two consecutive years, one year and two years, which reduces the cost, shortens the seed collection cycle, ensures the quality of seeds and improves the yield ebb flow table.

Selection and requirements of farmland plots

Because onion seedlings are sensitive to saline alkali reaction, fertile, loose and neutral soil plots with strong water ...
... and fertility should be selected. At the same time, the land should be flat and convenient for drainage and irrigation. The base fertilizer shall be sufficient. Generally, 4000-5000 kg of organic fertilizer, 50 kg of diammonium phosphate and 30 kg of potassium sulfate shall be applied per mu. It is required that the feces shall be mature, fine, shallow and uniform. As onion is a cross pollinated crop, it is necessary to do a good job in isolation. There shall be no onion and garlic crops within 500m around it.

Seed production technology in the first year

1.Selection of mother balls: choosing a good mother ball is the key to onion seed collection. Carefully observe the onion production process in the production field, select the plant with compact and symmetrical plant type, normal leaf color, thin and short leaf sheath, rapid expansion of onion, large individual when the false stem falls, no cracking of outer scales during harvest, no damage of diseases and pests, correct appearance, and harvest and storage with the characteristics of this variety. During autumn planting, another screening shall be carried out to eliminate the female balls that germinate, develop disease and decay during storage.

2.Timely planting: most plants in Shandong are planted in the first and middle of October. Onions usually have new roots and seedlings. When planting, the planting holes shall be opened according to the row spacing of 45 cm and the plant spacing of 35 cm. One female bulb shall be planted in each hole, nearly 4000 holes per mu. Planting should be a little deeper, and the top of bulb implantation hole should be covered with soil about 2-3cm, so as to facilitate overwintering and not easy to fall down after bolting the next year. Water in time after planting hydroponic grow table.

3.Field management: water once before overwintering to maintain proper soil moisture during overwintering. The planting holes shall be properly covered with fallen leaves, withered grass or horse dung to ensure safe winter. After the planting plants turn green the next year, water the turning green water, and apply an appropriate amount of nitrogen fertilizer in combination with watering. In order to improve the ground temperature, it can be cultivated for 1-2 times. Before bolting, water and fertilizer should be properly controlled to avoid overgrowth. After bolting and flowering, combined with watering, topdressing can be carried out again as appropriate. Nitrogen fertilizer is mainly used before flowering, and phosphorus and potassium fertilizer is added after flowering, so as to promote the plumpness of seeds. In the flowering period, due to the dry climate, in order to improve the pollen viability, spray flowers with water mist at 11-12 noon every day according to the weather conditions. In case of rain or excessive air humidity during the flowering period, the anthers cannot crack and affect pollination, in order to improve the pollination seed setting rate, artificial assisted pollination should be carried out. Prevent the flower bolt from falling down, and erect a support bolt in time.

4.Pest control: downy mildew, Botrytis cinerea and ground worm are the main points of prevention and control. The drug control method for downy mildew is the use of 75% chlorothalonil wettable powder 110 grams +50 kg water per mu for 1-2 times. The control method of Botrytis cinerea is in the early stage (early May), with 25% carbendazim wettable powder 100 grams +50 kg water spraying 1-2 times per mu. The drug control of ground maggots is to control the larvae in time in mid May, and irrigate the roots with 60ml 50% phoxim EC + 50kg water per mu.

5.Harvest at the right time: about 3 weeks after the full flowering period, a small amount of capsules on the top of the flower ball turn yellow and crack, and the harvest can begin before the seeds are scattered. The flowering period of different species and different bolting in the seed collection field is not neat, so it must be harvested many times and in batches. When harvesting, cut it from 30cm below the flower ball and ripen it in a well ventilated place. After one week, cut off the flower bolt and then air the fruit. After threshing, it is still air dried until it is fully dried, removed, bagged and stored. 50-80kg onion seeds can be produced per mu.

Seed production technology in the second year

1.Protect the seed collecting field: when collecting the seed ball for the first time, pay attention not to step on or pull out the mother plant. After the seed bulb is harvested, the mother bulb will spend the summer in situ without weeding or cutting the remaining flower bolts, so as to shade, reduce the ground temperature and protect the bulb through the hot summer. When the soil is dry, small water shall be poured to prevent the mother bulb from drying and shrinking. Drainage and waterlogging prevention shall be carried out in time after heavy rain to avoid mother bulb rot.

2.Strengthen rural management: after autumn, before the mother bulb germinates, clean the countryside, remove weeds and flower bolts, and loosen the soil through middle tillage to promote the mother bulb germination. Timely water to keep the ground moist, and apply 15kg compound fertilizer per mu in combination with watering. 70% methyl tobrozine 800 times liquid was sprayed 1-2 times to control various diseases. Root irrigation with 48% lesbon EC 1500 times solution was used to control pests. If there is a lack of plants, the ball can be replanted in the first and middle of October. Other management in winter and the coming year is the same as the seed production technology in the first year. The focus is to strengthen field management to ensure sufficient fertilizer and water, especially to strengthen topdressing. The seed production yield in the second year is high, and the amount of topdressing should be 2-3 times that in the first year. In the early stage, topdressing nitrogen fertilizer is mainly paid attention to, and in the later stage, topdressing phosphorus and potassium fertilizer is mainly applied. And pay attention to pest control.