How many jin per mu is the onion yield? What causes onion tip burn?

If one had to describe onions with a Chinese idiom, "mixed feelings of grief and joy" would be the most fitting. Although onions are hard to handle and often leave people in tears, this still cannot stop people from loving them, so the number of people growing onions is also increasing. Apart from price, the issue growers care about most is yield.

How many jin per mu is the onion yield

Onion yield per mu is 6000-10000 jin; the key is how well it is managed, mainly that after transplanting the seedlings must all be kept alive and their growth must be uniform, and that fertilizer and water management in the later stage must be meticulous.

If sowing in autumn is too early, if the seedlings are too large, or in a warm winter year, onions easily pass through vernalization and bolt prematurely; when this happens, the flower stalk can be pinched off below the swollen part of the stalk. If double-headed onions are found growing in the field, one head can be removed to let the other head continue growing. During the bulb enlargement stage, onion plants must not be stepped on and flattened, otherwise the normal transport of nutrients will be affected, leading to reduced yield.

What causes onion tip burn

The causes of onion tip burn are divided into human factors and disease invasion. Human factors are mainly caused by improper management during planting, while natural diseases are mainly gray mold and downy mildew. Details are given below:

1. Symptoms

Gray mold tip burn: at first white spots appear on the leaves, mostly developing from the leaf tip downward, and can extend 2-3 cm downward and dry up. When humidity is high, large amounts of gray mold grow on the withered leaves.

Downy mildew tip burn: after the leaves are damaged, oval or elliptical lesions begin to form, initially yellowish white, later turning grayish white; when humidity is high, a thin white mold layer forms on the surface of the lesions.

2. Control measures

Agricultural measures: choose disease-free seeds or disinfect the seeds. Seed selection should be carried out in disease-free plots; the seed disinfection method is to soak the seeds in 50°C warm water for 30 minutes, remove them, then put them into cold water to cool, then remove them and germinate before sowing; practice crop rotation. Water in the morning on sunny days, and drain promptly after rain. For Welsh onions in protected cultivation, use drip irrigation or irrigation of hidden water under plastic film as much as possible. Apply plenty of fully decomposed organic fertilizer.

Chemical control measures: fumigation with smoke agents. Before the onset of gray mold or at the initial stage, use 200 g of 20% vinclozolin smoke agent per mu or 200-250 g of 15% procymidone smoke agent (Sumilex); before the onset of downy mildew, use 250 g of 20% chlorothalonil smoke agent. At the initial stage of disease, use 250 g of 15% cymoxanil-mancozeb smoke agent (Curzate), carry out smoke fumigation in the evening, set 4-5 points per mu, light with fire, seal and fumigate after smoke appears, fumigate once every 7 days, for 2-3 consecutive fumigations.

Growing conditions for onions

1. Temperature: onions have strong adaptability to temperature; seeds and bulbs can germinate slowly at 3-5°C, the suitable temperature for seedling growth is 12-20°C, for leaves 18-20°C, and for bulbs 20-26°C; robust seedlings can withstand low temperatures of -6-7°C.

2. Light: onions are long-day crops; the bulb enlargement stage and the bolting and flowering stage require more than 14 hours of long daylight. Under high temperature and short daylight, they only grow leaves and cannot form bulbs. The suitable light intensity is 20,000-40,000 lux.

3. Water: onions should be supplied with sufficient water during the germination stage, the peak seedling growth stage, and the bulb enlargement stage, but water must be controlled during the seedling stage and before overwintering to prevent seedlings from growing excessively and suffering freezing damage; irrigation must be controlled 12 weeks before harvest.

4. Soil: onions have strong adaptability to soil; fertile, loose, well-aerated neutral loam is suitable. Sandy loam easily achieves high yield, but clay loam produces bulbs that are plump, good in color, and resistant to storage. The root system has weak fertilizer uptake capacity, so high yield requires sufficient nutrient conditions.

How to grow onions

1. Timely watering: 20 days after transplanting, onions enter the seedling recovery stage. At this time, they cannot be watered heavily, but they also cannot lack water, so watering should be frequent but each watering should be small in amount. The principle is not to let the seedlings wilt and not to let the ground dry out, so as to promote rapid rooting of the seedlings.

2. Reasonable fertilization: during the peak leaf growth stage and the bulb enlargement stage, onions should be fertilized and watered at the right time, applying 15 kg of diammonium phosphate, 20 kg of diammonium phosphate, and 3-5 kg of potassium sulfate per mu respectively, but excessive nitrogen fertilizer must be avoided.

3. Cultivation and loosening the soil: during the onion seedling stage, cultivate and loosen the soil 3-4 times, after each watering; during the stem and leaf growth period, do it 2-3 times; after the plants close the rows, stop cultivation. The suitable cultivation depth is about 3 cm; it should be shallow near the transplanted plants and deep away from the plants.

4. Cutting off flower stalks: cut onions off from the lower part of the flower bud before the flower head forms, to prevent flowering from consuming nutrients, promote side bud growth, and form fuller bulbs. At the same time, spraying Diguozhuangdiling at the right time helps increase yield.

5. Harvest time: onion harvest is generally from the end of May to the beginning of June. When the leaves gradually begin to turn yellow from bottom to top, the false stem softens and begins to fall over, the bulb stops enlarging, the outer skin becomes leathery, and the plant enters the dormant stage, this marks that the bulb has matured and it should be harvested in time.

It can be seen that the yield per mu of onions is still very high, and of course this is greatly related to people's growing methods and management. Onions have strong adaptability, but to obtain high yield, understanding their growth habits and managing them reasonably are also very important.