Planting time of leek

Leek leaves, scape and flowers are used as vegetables, seeds can be used as medicine, with kidney, stomach, refreshing, antiperspirant and astringent effects, leek is adaptable, cold-resistant and heat-resistant, and is cultivated all over the country. Let's take a look at the planting time and conditions of leek.

Planting time of leek

The sowing time of leek can be divided into three types: spring sowing, summer sowing and autumn sowing.

1. Spring sowing: it is better to sow early than late, and when the local temperature is stable at 5-10 ℃ in spring, the land is not fully melted, and the return to grain period is not moist to the surface, so it is easy to emerge seedlings. This sowing method also avoids grass damage, because leek seedlings come out quickly after sowing, and the temperature at that time is not suitable for weed germination, resulting in a jet lag. Therefore, it is recommended that people try to use this kind of sowing method.

2. Summer sowing: generally sowing after the cucumber and tomato strike, at this time the high temperature is prone to drought and waterlogging, the sowing amount is about 1/3 larger than that in spring, and the soil cover is not easy to be too thick, keeping the soil moist, which is conducive to the emergence of the whole seedling.

3. Autumn sowing: generally sowing before and after the Beginning of Autumn, the sowing amount is twice as large as that in spring, and the management is mainly dry and wet. Attention should be paid to grass damage in the later stage. Autumn sowing is generally not recommended.

Planting conditions of leek

Leek belongs to perennial root vegetables of Liliaceae. It is highly adaptable, cold-resistant and heat-resistant. It is cultivated all over China. Many areas in the south can be produced all the year round, although the aboveground parts of the north die in winter, the underground parts go into dormancy, and the topsoil germinates and grows after thawing in spring.

1. Temperature: leek likes cold and cool, cold-resistant and heat-resistant, the optimum temperature for seed germination is above 12 ℃, the growth temperature is 15 ℃ to 25 ℃, and the underground part can withstand lower temperature.

2. Light: medium light intensity, strong negative resistance. But the light is too weak, the accumulation of photosynthate is less, the tiller is small and weak, the yield is low, it is easy to senescence prematurely; the light is too strong, the temperature is too high, the fiber is too much, the quality is poor.

3. Moisture: the suitable air relative humidity is 60-70%, and the soil moisture is 80-90% of the maximum field capacity.

4. Soil: Chinese chive has strong adaptability to soil texture, and the suitable pH is 5.56.5. It needs a large amount of fertilizer and has strong fertilizer tolerance.

Classification of leek varieties

Chinese leek is very rich in variety resources, which can be divided into four types according to the edible part: root leek, leaf leek, flower leek and leaf flower leek.

1. Root leek: root leek is mainly distributed in Yunnan, Guizhou, Sichuan, Xizang and other places, also known as leek, broad-leaf leek, big-leaf leek, mountain leek, chicken foot leek and so on. Mainly edible roots and bolts. The root system is stout, fleshy, pungent and can be processed, pickled or cooked. The flower stem is fat and tender, can be fried and eaten, and the tender leaves can also be eaten. Root leek is mainly asexual reproduction, strong tillering ability, vigorous growth and easy cultivation. Mainly to harvest in autumn.

2. Leaf leek: the leaf of leaf leek is wide and thick, tender, and the bolting rate is low. Although it can bolt for food at the stage of reproductive growth, it is mainly eaten by leaf and leaf sheath. It is widely cultivated all over our country. This kind is mainly used in softening cultivation.

3. Flower leek: the flower leek is specially used to harvest the flower stalk of leek for food. It has short leaves, rough texture, strong tillering ability and high bolting rate. The flower stem is tall and thick, the quality is brittle and tender, the shape is similar to the garlic bolt, the flavor is especially beautiful. There are more cultivation in Lanzhou City and Taiwan Province of Gansu Province in China. Shandong and other places also have sporadic introduction and cultivation. There are many varieties of leek, such as small leaf species: strong bolting and tillering, narrow and short leaves, dense color, thin and greenish leaf sheath, hard leaf and leaf sheath, early maturity, both leaf and flower, medium quality; young leek: bolting is very strong, flower stem grows, leaf width is wide and long, dark green, leaf sheath is large, yellowish red. The leaves and leaf sheaths are hard, the bolting period is long, they can bolt all the year round, and the leaves are not suitable for eating, mainly bolting. Nianhua No. 2: the flower stem is thick, good quality, low temperature tolerance.

4. Leaf-flower dual-use leek: the leaves and bolts of leaf-flower dual-use leek are well developed and are edible. At present, most of the leek varieties cultivated in China belong to this type. This type can also be used for softening cultivation.

Planting technique of Chinese chive

1. Root cultivation: the harvest time of leek should be suitable. Generally, 4-5 crops are harvested every year, 2-3 crops are harvested in June and July in summer, and the rest of the time is mainly for root cultivation, so that the plant can produce more tillers and lay the foundation for high yield in autumn. The basic requirement of root cultivation is that the stubble height should be suitable when harvesting leek, which is generally harvested at the rhizome about 4 cm off the ground. After each harvest, the knife edge will be slightly raised. Fertilizing and watering should not be applied within 2 days after cutting, so as not to cause diseases and insect pests caused by germs on the knife edge, resulting in rotten roots.

2. Root removal: before the leek germinated after soil thawing in early spring, iron cuttings were used to dig ditches of about 6 cm in depth and width in the rhizosphere soil of leek, and the soil among plants in each clump was removed to reach the root. Make it expose the rhizome, at the same time remove the dead tillers and small tillers, spread the dug soil between the rows to dry, and then pinch up the rhizome, fill it with fine soil and bury it. When filling the soil, it is best to add an appropriate amount of plant ash to control root maggots.

3. Root inversion: replanting old leek roots can not only re-coruscate the production potential, but also use waste roots, reduce costs, come faster than re-sowing, and help to maintain the purity of varieties. First use four-toothed fork or pick to turn up the leek root, choose disease-free and insect-free, but also have production capacity, cut off the overlong fibrous root, remove the non-tillering ability and rotten rhizome for replanting. It can be cultivated in flat bed or furrow. The distance between holes planted in the bed is 8: 10 cm, and about 10 plants per hole, the yield will be reduced when the seed is sparse. The row spacing of ridge and furrow hole planting was 60 cm, the seedling bandwidth was 30 cm, and 4 rows were planted.

4. Cultivate the soil: the leek root system has to "jump root" upward every year to form a hypertrophic root node-cucurbit head. The larger the root node, the more nutrients are stored, so the leek will take root early and have a high yield in the second year. Therefore, cultivating soil and fertilizing Chinese chives can promote the growth and development of new roots of Chinese chives, prolong the life span of Chinese chives and prevent lodging. The time of soil cultivation should be carried out before the root germination of leek after soil thawing, and the thickness of soil should be determined with the height of "jumping root". Generally, it is suitable for 3-4 cm.

5. Cover ash: when planting leek in autumn and winter, after applying sufficient basic fertilizer, cover the border with fine crushed coal slag with a thickness of 2-3 cm, and apply appropriate amount of water-soluble fertilizer during the growth period. In this way, the leek soil is loose, the permeability is good, the weeds are not easy to grow, the pathogens are less, and the effects of heat preservation, moisturizing, fertilizer preservation and drought resistance are good. The leaves of leek grow thick green, grow fast and have strong tillering ability. it not only has high yield and crisp texture, but also does not harm the meristem and buds in leaf sheath during harvest, which is more conducive to the growth and harvest of leek in the following crop.

6. Sand culture: planting Chinese chives year after year can easily lead to the occurrence of leek maggots. Sand culture can solve this problem. Using sandy soil or other substrates as cultivation substrate and pouring nutrient solution has the characteristics of simple management, low investment, quick effect and high income, so it is especially suitable for cultivation in courtyard or idle land. The sand culture bed can be made into square ponds, diamond ponds or polygonal ponds with equal length and width, and the length and width depend on the place. The height of the bed is 18 to 20 cm; and the river sand with diameter 1~2mm is better.

Insect pest control of leek

The main pest of leek is leek maggot. Leek maggots seriously endanger the growth of leek. According to the actual situation, timely measures should be taken to prevent and cure the leek maggot.

1. Adults: 5-6 generations of non-maggots occur every year, and the occurrence is the most serious in spring and autumn. The emergence period of adults is usually in April and September. Should choose sunny morning from 9 to 10:00, spray 2.5% deltamethrin EC 2000 times per mu.

2. Larvae: irrigate the root with 2% methylavermectin EC 500ml diluted to 1000 times per mu.

Disease control of leek

There are too many Rain Water in summer, so it is necessary to strengthen the prevention and control of the harm of leek. The main diseases of leek are Botrytis cinerea, blight, purple spot and so on.

1. Grey mold

[disease characteristics] White or grayish brown spots appeared on the leaves at the initial stage of the onset of Botrytis cinerea, and then expanded into prismatic or oval spots, which healed each other into large dead spots that withered the leaves. When wet, the surface of withered leaves is densely gray to grayish brown mildew. The pathogen overwintered mainly by sclerotia on the disease remains in the soil and spread by airflow. Botrytis cinerea of leek is harmful all the year round.

[prevention and control method] the effect of 78% Cobo 600x solution for ① is good. ② should increase the application of organic fertilizer, harvest properly, drain water in time after rain and reduce the humidity in the field. Old leaves and diseased seedlings were removed in time by ③.

2. Epidemic disease

[disease characteristics] the leek blight harmed the roots, stems and leaves, especially the pseudostem bulb. The damage words in the leaves were dark primary watery spots, then the leaves turned yellow and soft rot, the stems and roots showed brown soft rot, and the disease produced sparse white mildew when it was wet. The pathogen overwintered on the residue of soil disease (leek in greenhouse can occur all the year round), which was harmful to high temperature and humidity, the optimum temperature was 25-32 ℃, and the damage peak was about August.

[control method] in the early stage of the disease, 1000 times liquid of 50% ash nucleovir or 2000 times liquid of 40% sclerotia can be sprayed on cloudy days, and drugs should be sprayed evenly after each crop of leek harvest. In the selection of agents, attention should be paid to the selection of new fungicides with high efficiency, low toxicity and low residue, and should be applied alternately.