When are the onions planted in a few months

When is the onion planted? Due to the different climatic conditions in different regions, the suitable onion planting time in the north and south of my country is also different. Most varieties of onion in Shandong Province are sown in the open field in early September, and the seedling period is about 40-50 days. Sowing too early, the seedlings will grow big before winter, bolting is easy in the second year, it also consumes nutrients and reduces yield and quality. Sowing is too late, the seedlings are small, the root growth is stunted, and it is easy to freeze to death in the cold winter. The suitable planting period is from mid-to-late October to early November. Before planting, the seedlings have 3 to 5 leaves, the plant height is 15 to 20 cm, and the pseudostem thickness is 0.5 to 0.7 cm, which is the suitable seedling age. How to grow onions

1. Variety and land selection. Qinghai Province is a high-latitude area, so long-day varieties should be selected. The varieties used should be selected according to the climatic environmental conditions and cultivation habits, and the American hybrid variety "Bailuoke" can be selected. This variety has the characteristics of being large, tall, pure white color, and high-quality disease resistance. Varieties such as "Red Lantern" can also be used. The main exporter of my country's onions is Japan. Cultivated land should be selected in Sichuan water areas with good soil strength, flat terrain, and good water and heat resources. Second, sowing seedlings

1. Sowing at the right time. Onions are generally planted before and after the beginning of autumn. The method can be drilled or broadcasted, and the seeding is required to be even. The amount of seed per hectare is about 1.8-2.25 kg (according to the germination rate as appropriate).

2. Seedling management. The onion emergence period is about 7-10 days. After most of the onions emerge, water is irrigated according to the moisture content. After 2 leaves are grown, 105-108 kg/ha of urea can be applied in combination with field tillage and weeding, and then irrigated. Generally, water is irrigated every 10 days.

3. Fake planting of green onion seedlings. Seedlings will start in mid-November. The green onion seedlings of the same seedling quality will be tied into small bunches, and the rootless and too short seedlings will be removed. The bunched green onions will be placed in the shade. From the base to the middle and upper parts, the wet soil is good, and then the second row is erected and the wet soil is fake for overwintering.

4. Soil treatment. In the next year, onion planting plots will be treated with chemical soil treatment for underground pests and weeds before winter, and winter water must be drenched. For soil treatment of underground pests, spray 3750-6000 ml of phoxim EC per hectare of ground (because it is easy to be decomposed by light, it should be carried out in the evening), and evenly turn it into the soil, or 5% phorate granules 22.5-33.75 Tons are applied evenly into the soil. For the treatment of weed soil, spray 2250 ml of field herbicide or 48% trifluralin per hectare, or spray 2250-3000 ml of 50% acetochlor or 1875-2250 ml of Caucaotong, and turn them into the soil evenly .

Onion planting time and planting method

3. Apply enough base fertilizer and 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 the soil at a depth of 20 cm. It has weak fertilizer and water absorption capabilities, and requires higher soil requirements. Avoid continuous cropping of onions, and generally rotate once every 3 years.

1. Soil preparation and fertilization. When preparing the land, plow deeply, the depth of plowing should not be less than 20 cm, the plot should be flat, easy to irrigate with small water (overflooding) without accumulation of water, and the land preparation should be very fine. Generally medium fertility fields (bean stubble, corn and other dry crops are better) per hectare, apply 30 cubic meters of high-quality decomposed organic fertilizer, and 450-600 kg of diammonium and phosphorus-potassium compound fertilizer as base fertilizer. The planting method should adopt flat borders, generally the border width is 0.9-1.2 meters (depending on the width of the mulch), and the groove width is 0.4 meters for easy operation.

2. Laminating. Laminating can increase ground temperature and increase output. Irrigate the plot before mulching. After the soil dries a little, follow the raking and mulching to protect the moisture, and the edge of the film should be tight. After mulching and planting before planting, drill the eyes according to the row spacing of 20 cm × 15 cm. The eye punch can be self-made, 12 eye punches at a time.

3. Colonization. The onion can be planted when the surface soil melts about 5 cm in February of the following year. The depth of planting should not be buried in the core leaves and the seedlings should not fall. It is better to water the seedlings without falling and no water on the border. Planting seedlings should be straight and shallow (approximately 2 cm), and the roots should be tightly combined with the soil. If it is planted too deep, it will easily affect the enlargement of the bulb. After planting, the onion enters the slow seedling stage, and the place where conditions permit can be watered with planting water, and water again when the seedlings have slowed down and grow new leaves.

4. Reasonable dense planting. Density is an important factor that constitutes yield. Onions have few leaves and strong erectness, suitable for dense planting. Experiments show that reasonable close planting can increase the yield of onion per unit area, and the planting density depends on the characteristics of the variety, soil conditions and production goals. Generally, the middle-mature varieties are between 330,000 and 600,000 plants per hectare. If the row spacing is 20 cm × 15 cm, then 495,000 plants per hectare will be planted.

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, and the soil sees dryness as the limit. Watering and top dressing should also depend on seedling conditions and soil fertility, and generally should be "small water and frequent irrigation". Fertilizer and water management should grasp the principle of "control before the year and promote after the year". During the growth period, in addition to the base fertilizer, topdressing should be carried out to ensure the growth of seedlings. For plots with poor soil strength, 105-150 kg of urea per hectare can be applied in combination with watering.

1. Ye vigorous growth period. When onion has 6 leaves and 1 heart, it will enter the vigorous growth period. At this time, the amount of fertilizer required is relatively large. 300 kg of urea can be sprayed on the film surface per hectare, and 300 kg of 48% NPK compound fertilizer can be added to meet the vigorous growth period of onions. The need for nutrients.

2. Bulb swelling period. When the aboveground part of onion reaches 9 leaves, it will enter the bulb expansion stage, the plant will no longer increase, the leaf assimilation transfers to the bulb, and the bulb rapidly expands. This period is another peak of fertilizer demand, especially the demand for P and K fertilizers. . Practice has proved that applying 450 kilograms of 48% NPK compound fertilizer per hectare can ensure the normal swelling of bulbs.

3. Prevention and control of pests and diseases. Onions are susceptible to downy mildew, purple spot and rust. In rainy and humid weather, downy mildew and purple spot are more serious. Downy mildew and purple spot can be sprayed with 75% chlorothalonil 600 times solution or 64% antiviral alum 500 times solution; 25% swiss mold or 65% mancozeb 600 times solution can also be used to prevent and control. Use 15% triadimefon 1500-2000 times liquid spray to prevent and control rust, spray once every 10-15 days, and spray 3-5 times continuously. The last use of the above pesticides should be 7-10 days apart from the harvest period. Onion thrips can be sprayed with 40% omethoate 800 times liquid or 10% imidacloprid 300 g/ha. These two pesticides are only allowed to be used once during the growth period, and there should be an interval of more than 15 days from the harvest period.

Five, timely harvest

1. When the leaves are not yellow before harvesting, spray the leaf surface with MH 500 mg/kg to prevent germination during storage.

2. Stop watering 7-10 days before harvesting to prevent onions from being unable to store due to absorbing enough water in the field.

3. After 30% of the above-ground tubular leaves fall naturally, it is the right time for harvest. At this time, the first and second leaves at the base of the plant are withered and the third and fourth leaves are still green. The false stems are dehydrated and soft, and the above-ground parts naturally fall down. . The harvest should be carried out on a sunny day. The main plant is pulled out by roots and dried in the field for 1-2 days. When drying, cover the onion with leaves, only the leaves but not the heads, and the yield is 60-90t per hectare. In order to increase the commodity rate, the morning market can also be harvested in advance.

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