The planting method of onion

Onions, also known as ball onions, onions, jade onions, etc., are biennial herbs of the family Liliaceae. different spheres are related to morning and evening maturity. in general, the flatter the balls are, the earlier the maturity is, and the yields of different varieties are quite different. the flat varieties with early maturity generally have a yield of 45005500 kg per mu, and the mid-late maturity varieties generally have a yield of 5000,5500kg per mu. Let's take a look at the planting method of onions.

Cultivated varieties of onion

1, red onion: onion appearance purplish red, fleshy fleshy, oblate or spherical, 8cm in diameter. It is resistant to storage and transportation, has a short dormancy period and sprouts early, showing early to middle maturity, and harvested from late May to early June. It is widely cultivated in East China. Representative varieties include Shanghai Hongpi and so on.

2. Yellow onion: onion brass to light yellow, fleshy, yellowish and soft, spicy. Oblate, 6-8 cm in diameter. More resistant to storage, transportation, precocious to medium maturity. The yield is lower than that of red bark, but the quality is better, so it can be used for dehydration processing. Representative varieties are Lianyungang 84-1, DK Yellow, OP Yellow, Dabao, Laixuan 13 and so on.

3. White onion: onion white, fleshy scales, white, flat spherical, some are tall round and spindle-shaped, 5cm in diameter. Good quality, suitable for dehydration processing of raw materials or canned food ingredients. But the yield is low and the disease resistance is weak. Early autumn sowing in the Yangtze River basin is easy to bolting in advance. The representative varieties are Hami white skin and so on.

Planting conditions of onion

1. Temperature: onion has strong adaptability to temperature. Seeds and bulbs can germinate slowly at 3-5 ℃, and the optimum temperature for seedling growth is 12-20 ℃. Healthy seedlings can tolerate the low temperature of 6-7 ℃. Bulb expansion needs a higher temperature, but if the temperature is too high, the growth will decline and go into dormancy.

2. Illumination: onion is a long-day crop, which needs more than 14 hours of long sunshine to grow normally during bulb expansion and bolting and flowering period. under the condition of high temperature and short day, only long leaves can not form onion, and the suitable light intensity is 20 ~ 40 thousand lux.

3. Moisture: onions should be provided with sufficient water during germination, seedling growth and bulb expansion. However, it is necessary to control moisture in the seedling stage and before overwintering to prevent the seedlings from growing and suffering frost injury. Drought-resistant, suitable for 60% to 70% humidity, high air humidity is prone to diseases.

4. Soil: onion has strong adaptability to soil, and it is suitable to use neutral loam with loose fertility and good aeration. Sandy loam is easy to get high yield, but clay loam has full bulb, good color and storage resistance. The ability of onion root system to absorb fertilizer is weak, and sufficient nutritional conditions are needed for high yield.

Seedling raising techniques of Onion

The main results are as follows: 1. Sowing time: the selection of suitable sowing time is the key to cultivate strong seedlings, such as large seedlings too early, easy bolting after overwintering, weak late sowing seedlings, poor cold resistance, small phosphorus stems and low yield. Taking the Huang-Huai River Basin as an example, the best sowing date is the first and middle of September.

2. Sowing quantity: under normal circumstances, the sowing amount of onion in the seedling bed is 40.5 kg per mu. In consideration of eliminating and thinning 20% of the weak and inferior seedlings, the cultivation area should be 15 times that of the seeding bed, and the sowing rate should be increased if the germination rate is less than 70%.

3. Fertilizing the border: the border is 1.4 to 1.5 meters high, 27 centimeters wide, 15 kilograms of phosphorus and calcium per mu after leveling, 4 square meters of mature organic soil fertilizer per mu as base fertilizer, and 10 kilograms of urea per mu combined with watering after seedling emergence.

4. Sowing method: after the border is flattened, it is watered first, and then sowed evenly. Then cover 0.8 cm of nutritious soil to ensure that all seedlings are sown. If the soil moisture can not meet the requirements of seedling emergence after sowing, spray water can be used to promote seedling emergence, or it can be sowed after sprouting.

5. Seedling emergence management: onion should pay attention to the prevention and control of mildew and blight after emergence. The method is to use 150 grams of 50% carbendazim or 40% chlorothalonil per mu and spray 30-40 kg of water evenly.

Field management of onion

1. Watering: about 20 days after onion planting, onions enter the slow seedling stage, at this time can not be a large number of watering, too much watering will reduce the ground temperature, slow seedlings slow. At the same time, the new roots of newly planted seedlings have not yet germinated, and they can not be short of water. At this stage, onions should be watered more times and less each time. The principle is not to wilt the seedlings and not to dry the ground, so as to promote the rapid rooting and survival of the seedlings.

2. Fertilization: onions need 1315kg of nitrogen per mu, 8kg of phosphorus and 10kg of potassium. Do not overweight nitrogen fertilizer. Spring sowing onion seedlings should keep the soil moist, watered and ploughed frequently before and after being unearthed, and fertilized and watered timely during the peak leaf growth period and bulb expansion period. Diammonium phosphate 15kg, diammonium phosphate 20kg, potassium sulfate 3kg / mu were applied respectively.

3. Loosening soil: loose soil is mostly beneficial to the development of onion root system and bulb expansion. Generally, it is necessary to carry out 3-4 times at seedling stage, after each watering, 2-3 times during stem and leaf growing period, and stop mid-tillage after closing ridges. The middle tillage depth should be about 3 cm, the planting plant should be shallow, and the place far away from the plant should be deep.

4. Bolting: for early bolting onions, cut off from the lower part of the bud or separate from the tip of the flower, tear two pieces from the top to the bottom, prevent flowering from consuming nutrients, promote the growth of lateral buds and form more substantial bulbs. at the same time, spray Di Guang Diling at the same time. The practice shows that for the plants with early bolting, a certain yield can still be obtained after taking bolting measures.