The suitable temperature for leek growth depends on the growth stage, and the temperature required for different growth stages is also different. Among them, when seeds germinate, the temperature should be controlled above 12 degrees, preferably between 15 ~ 18 degrees, too low will reduce the germination rate. The suitable temperature for seedling growth is between 12- 18℃. When the seedlings grow to the growth stage, the suitable temperature is between 15-28 degrees. Neither too high nor too low, otherwise it will affect growth.

Second, the growth cycle

1. Germination period: the period from seed germination to the first true leaf growth is the germination period, and the whole excavation process takes about 10 days. However, the time required for different varieties is not exactly the same. Some varieties germinate slowly, and the seedling stage is about 12- 15 days, or even longer.

2, seedling stage: from the first true leaf to the ability to divide plants is the seedling stage. General varieties need 70-80 days, and fast-growing varieties need 60 days. At this growth stage, the growth of aboveground parts is relatively slow, mainly because of the growth of roots. When the seedlings grow to 18-20 cm, they can be fixed.

3. vigorous growth period: from the perspective of plant division ability, it is vigorous growth period and division begins. The specific number of branches also depends on the variety. Among them, narrow-leaf varieties are divided into four or five times, and wide-leaf varieties are divided into two or three times a year. Attention should be paid to the management of light and temperature during this period.

How to manage leeks in autumn? Management method of leek in autumn

"Leek is fragrant in spring and smelly in summer, so beginning of autumn can eat leek healthily for a long time." After beginning of autumn, the demand for Chinese chives will increase obviously, and the temperature conditions are just suitable for the growth of Chinese chives, which is a favorable opportunity to cultivate root growth and plant health. So how to manage leeks in autumn? What is the management method of leek in autumn?

Management method of leek in autumn

One is the watering and fertilization of leeks in beginning of autumn.

After beginning of autumn, the weather turned cool, the sunshine was abundant, the precipitation was less and less, the photosynthesis of leek was vigorous, the growth was rapid, and the nutrition accumulated to the roots, which was the key period for strong seedlings and strong roots. Therefore, strengthening the management of water and fertilizer in autumn is conducive to the rapid growth and accumulation of nutrients in leeks.

A quantitative problem must be mastered when watering leeks in winter. It should be decided according to the rainfall in autumn, because leeks are afraid of waterlogging in autumn, so don't water them without drought. If the rain is too heavy, we must do a good job of drainage and waterlogging prevention to prevent leeks from rotting roots and leaves, resulting in reduced production.

The topdressing amount of leek depends on soil conditions. Carry out formula fertilization. Topdressing and secondary fertilization should be carried out according to the nutrients needed for leek growth. You can use fully decomposed cake fertilizer and biological bacterial fertilizer, 500 kg per mu, or apply diammonium phosphate 150 kg, and you can't use compound fertilizer with excessive potassium content. The time should be controlled between beginning of autumn and summer, and water should be done in time after topdressing.

The second topdressing should be carried out before the autumnal equinox, and the fertilizer consumption can be half of the second fertilization.

Second, the length control of leek after cold dew

After the cold dew, the weather is getting colder and the leek grows slowly. At this time, we should stop watering and topdressing, so that leek nutrition can return to the roots as soon as possible and accumulate nutrients.

Third, first frost and then leek hypnosis

After the first frost, a wind barrier inclined to the north of 1.3 ~ 1.5 meters was set in the front of the south side of the border, which reduced the temperature of the border, forced the leek to go to bed early and reduced the nutrient consumption. After beginning of winter was covered, the wind barrier tilted to the south by 15 degrees, making the southern boundary a warm boundary.

Management methods of leek in autumn. Management of leeks in early winter Before covering, all the dead leaves and sundries in the border should be cleaned up, the dead leeks should be cut off, and 20 kilograms of urea should be applied per mu with water. After underwater infiltration, build a small arch shed and cover it with a film grass curtain. Open the straw curtain at 9 o'clock every morning, cover it at 2 o'clock in the afternoon, let it dry for about 5 hours, and then dim.

After 3 ~ 5 days, after the leek germinates, the film is removed and sprayed with 25% carbendazim wettable powder or 40% triadimefon aqueous solution to prevent the leek gray mold. After the application, cover the soil for 2 ~ 3 times, with a total thickness of 5 ~ 10 cm. After the leek is unearthed, it is bacon. 165438+1In late October, cut the leek when it grows to 35cm, and water and fertilize it after harvesting.

V. Prevention and control of pests and diseases

The diseases that need to be controlled in summer and autumn are root rot, epidemic disease and leek wilt. Sudden heavy rain in hot weather and sudden high temperature in sunny days caused the leaves at the bottom of leek to be scalded, and then the whole plant died. Although the root system is not seriously damaged, it also seriously affects the growth of new roots.

For root rot, roots should be watered with rooting agent in time to supplement organic matter, such as humic acid organic fertilizer, bactericide and Trim amino acid foliar fertilizer. For epidemic diseases, 400-fold solution of 64% antiviral alum wettable powder or 500-fold solution of 50% metalaxyl copper wettable powder can be selected and sprayed three times every seven days 1 time. Prevention method: drain the rainwater in time, and then irrigate it with well water. A new variety Yiyuan 1 leek can be planted, which has strong disease resistance and only needs pest control.

There are insects in winter, and leeks are generally free from pests, mainly to control stem borers, the scientific name of which is phosphorus borer. Lepidoptera insects. It is a drilling pest in leek production. It eats leek pseudostems with larvae. The adult is a small black moth, with a body length of 5 ~ 6 mm, green fluff on the front and rear wings, and yellow zigzag ripples on the front wings. When not moving, the wings form a triangle, light green, about 10 mm long. It is particularly harmful to leeks. Once damaged, it will directly affect the yield of leeks, or even be destroyed.

Control method: control with pyrethroid pesticides once every 7 days. If adults are found, avermectin should be sprayed once every 7 days and twice in a row.