The onion planting time is a few months

When is the onion planted? Due to the different climatic conditions in different regions, the suitable onion sowing time varies in the north and south of my country. Most of the onion varieties in Shandong Province are sown and raised in the open field in early September, and the seedling period is about 40 to 50 days. Seeding is too early, the seedlings grow up before winter, it is easy to bolt in the next year, it also consumes nutrients and reduces the yield and quality. Seeding is late, the seedlings are small, the root system is poor in growth and development, and it is susceptible to freezing and death in cold winter. The suitable planting period is from mid-late October to early November. Before planting, the seedlings have 3 to 5 leaves, the plant height is 15 to 20 cm, and the false stem is 0.5 to 0.7 cm thick, which is the appropriate seedling age. Onion cultivation method

1. Variety and land selection. Qinghai Province is a high-latitude region, and long-sunshine varieties should be selected. The varieties used should be selected according to the climatic and environmental conditions and cultivation habits, and the American hybrid variety "White Rock" can be selected. This variety has the characteristics of large, high pile, pure white color, high disease resistance, etc., and "Red Lantern" and other varieties can also be selected. The main exporter of onions in my country is Japan. The cultivated land should be selected in the Sichuan water area with better ground power, flat terrain and better water and heat resources. Second, sowing and raising seedlings

1. Sowing in time. Onion sowing is generally carried out around the beginning of autumn. The method can be sowing or spreading. It requires uniform sowing. The amount of seed per hectare is about 1.8-2.25 kg (according to the increase and decrease of the germination rate as appropriate). Each hectare of seed bed can be used for transplanting seedlings of about 15 hectares.

2. Seedling management. The onion emergence period is about 7-10 days. When most of the onion emerges, it will be irrigated according to the condition of moisture. After 2 leaves have grown, it can be combined with cultivating hoe to apply urea 105-108 kg/ha, and then irrigate. Generally irrigate every 10 days.

3. False planting of spring onions. Start seedlings in mid-November, tie onion seedlings of the same seedling quality into small handles, remove unrooted, too short seedlings, place the row of onion seedlings in a row in the shade, and stand after a row of onion seedlings From the base to the middle and upper part, the wet soil is Yonghao, and then the second row is planted again to overwinter.

4. Soil treatment. In the next year, the onion plots should be treated with pesticide soil and insecticides for underground pests and weeds before winter, and filled with winter water. Underground pest soil treatment can be sprayed with 3750-6000 ml of phoxim emulsifiable concentrate per hectare (because it is easily decomposed by light, it should be carried out in the evening), and evenly turned into the soil, or the 5% formazan granules 22.5-33.75 Tons are evenly applied into the soil. Weed soil treatment can be sprayed with Tianfu herbicide or 48% trifluralin 2250 ml per hectare, or 50% acetochlor 2250-3000 ml or Caicaotong 1875-2250 ml, and evenly turned into the soil .

Onion planting time and planting method

3. Apply sufficient base fertilizer to plant closely. The root system of onion is a fibrous root system composed of string-shaped adventitious roots. The root system is underdeveloped and weak. The root group is mainly concentrated in 20 cm deep soil. It has weak fertilizer and water absorption capacity and has high requirements on soil. Avoid onion continuous cropping, usually once every 3 years.

1. Land preparation and fertilization. When arranging the land, deep ploughing should be carried out, the depth of ploughing should not be less than 20 cm, the plot should be level, so that it can be irrigated by small water (flooded irrigation) without water accumulation, and the land preparation should be very fine. Generally, medium fertility fields (bean stubble, corn and other dry stubble are better) apply 30 cubic meters of high quality decomposed organic fertilizer per hectare, 450-600 kg of diammonium and phosphorus and potassium compound fertilizer as base fertilizer. The planting method should be flat border, generally border width is 0.9-1.2 meters (depending on the width of the plastic film), and the trench width is 0.4 meters for easy operation.

2. Laminating. Laminating film can increase ground temperature and increase output. Irrigate the plot before mulching. After the soil is slightly dry, follow the raking and mulching to protect the soil. The edge of the membrane should be tight. After mulching, before planting, the holes were drilled at a distance of 20 cm × 15 cm. The eye-trigger can be self-made, 12 eye-trimmers at a time.

3. Colonization. The onion can be planted when the surface soil is melted by about 5 cm in February of the following year. The planting depth should be such as not burying the heart leaves or falling seedlings. It is better to water the plants without pouring seedlings or water on the border surface. The seedlings should be planted straight, shallow (about 2 cm), and the roots should be tightly combined with the soil. If planted too deep, it is easy to affect the expansion of the bulb. After the planting, the onion enters the slow seedling stage, and the planting water can be poured in the place where conditions permit, and when the seedling grows new leaves, then water it.

4. Reasonable dense planting. Density is an important factor in production. The onion has few leaves, strong uprightness, and is suitable for dense planting. Tests have shown that reasonable dense planting can increase the yield per unit area of ​​onions, and the planting density depends on the characteristics of the variety and the soil conditions and production goals. Generally, medium-mature varieties range from 33 to 600,000 plants per hectare. If the row spacing is 20 cm × 15 cm, 495,000 plants will be planted per hectare.

4. Field management. The relative humidity of the soil after planting should be maintained at 60-80%. If it is less than 60%, water supply is required, as long as the soil is dry. Watering and topdressing should also depend on seedling condition and fertility, and should generally be "little irrigation". Fertilizer and water management should master the principle of "control before years and promote after years". In addition to base fertilizer during the growth period, topdressing should also be carried out to ensure the growth of seedlings. For plots with poor soil power, 105-150 kg of urea per hectare can be applied in combination with watering.

1. Ye Wangsheng is growing. Onion 6 leaves and 1 heart enters the vigorous growth period. At this time, a large amount of fertilizer is required. 300 kg of urea can be spread on the film surface per hectare, and 300 kg of 48% nitrogen, phosphorus and potassium compound fertilizer can be added to meet the vigorous growth period of onions. The demand for nutrients.

2. Bulb enlargement period. When the aerial part of the onion reaches 9 leaves, it enters the bulb expansion period, the plant no longer increases, the leaf assimilation transfers to the bulb, and the bulb expands rapidly. This period is another peak of fertilizer demand, especially the demand for P and K fertilizers has increased significantly . Practice has proved that applying 450 kg of 48% NPK compound fertilizer per hectare can ensure the normal expansion of bulbs.

3. Prevention of diseases and insect pests. Onions are susceptible to downy mildew, purple spot and rust, rainy and humid weather, downy mildew and purple spot are more serious. Downy mildew and purple spot disease can be sprayed with 75% chlorothalonil 600 times solution or 64% antitoxin alum 500 times solution; it can also be controlled with 25% syringomycin or 65% mancozeb 600 times solution. Rust is controlled with 15% triadimefon 1500-2000 times liquid spray, sprayed every 10-15 days, and sprayed 3-5 times in a row. The last use time of the above pesticides should be 7-10 days away from the harvest period. Onion thrips can be controlled with 800% solution of 40% omethoate or 300 g/ha spray of 10% imidacloprid. These two pesticides should only be used once during the growing period, and should be separated by more than 15 days from the harvest period.

Five, timely harvest

1. When the leaves have not dried up before harvesting, spray the foliage with 500 mg/kg of qingqingsu (MH) to prevent germination during storage.

2. No watering 7-10 days before harvesting, to prevent the onion from being resistant to storage because it absorbs enough water while in the field.

3. The harvest period is 30% after the tubular leaves of the ground naturally fall down. At this time, the first and second leaves of the plant are withered, and the third and fourth leaves are also green. The false stem loses water and is soft, and the ground is naturally fallen . Harvest should be carried out on a sunny day. The main plant is uprooted and dried in the field for 1-2 days. The leaves are used to cover the shallots, only the leaves are not dried, and the yield per hectare is 60-90t. In order to increase the commodity rate, the market in the morning can also be harvested in advance.

Disclaimer: Some articles of this website are transferred from the Internet. If the legal rights of third parties are involved, please inform this website for processing. phone