How to manage codonopsis pilosula seedlings in the field.

Codonopsis pilosula seedlings are weak, afraid of drought, waterlogging, sun exposure and shade. The key to successful planting of codonopsis pilosula is seedling management. If it is not well managed, it will gradually die even if it has appeared.

(1) coverage

After spring sowing in rice fields, in order to conserve moisture, the border should be covered with grass, and the grass should not be too thick to achieve the purpose of conserving moisture, and weeding should be done when seedlings emerge. The climate in the south is hot, so it is necessary to set up a shade shed at the seedling stage to avoid strong light.

(2) Shading

No matter whether Codonopsis pilosula is sown in spring, summer and autumn, whether it is in the north or the south, it should be shaded according to the habit of Codonopsis pilosula in seedling stage, such as liking humidity, fearing drought and flood, liking shade and fearing direct sunlight. The common shading methods are covering grass for shading, shading net for shading and intercropping tall crops for shading. Shading with grass means covering the border with branches, reed curtains, wheat straw, wheat bran and corn straw. At the beginning of April of the second year after sowing in spring or autumn and winter, it is necessary to keep moisture and prevent sun exposure. Note that the covering should not be too thick or too thin. Too thick will affect the ventilation and light transmission of seedlings, and it is easy to form tall seedlings. Too thin can not achieve the purpose of shading and moisturizing, so it is advisable to expose the surface soil. Generally, full shading is started, mainly for moisturizing. After the seedlings germinate and are unearthed, the light transmittance will reach about 65,438+05%. When the height of the seedlings reaches 65,438+00 cm, gradually remove the plastic film, not all at once, so as to avoid the seedlings being killed by the scorching sun. When the height of seedlings is 15cm, grass and other mulch can be completely covered. The method of sunshade net is to build a sunshade net shed after spring sowing, and lift the sunshade net shed when it grows to 2 ~ 3 real leaves. In recent years, intercropping and interplanting tall crops are widely used in the north to solve the shading problem of codonopsis pilosula seedlings.

Intercropping and interplanting is a new seedling raising technology developed according to the requirements of shading and moisture conservation of codonopsis pilosula seedlings. This method can not only save plastic film, but also harvest grain, killing two birds with one stone. At first, people used the Party to participate in the intercropping of buckwheat, rape and hemp. In recent years, the intercropping of Codonopsis pilosula with corn and wheat has been adopted in northern China. The method of interplanting ginseng seedlings in corn field is as follows: the width of the border is 2. 1 m, the width of the border is 60 cm, codonopsis pilosula is planted in the border, and two rows of corn are planted on the border, with the plant spacing of 45 cm. Pay attention to ventilation, and knock off the leaves that are too dense under the corn, so as to adjust the light and avoid direct sunlight on ginseng seedlings. The method of raising seedlings in wheat field is: in spring, when the wheat seedlings grow to more than 20 cm, the seeds of codonopsis pilosula are sown in the wheat rows by loosening soil or spring irrigation, and the seedlings grow in the wheat rows with the help of spring precipitation or irrigation and get proper shade. When the wheat is ripe and harvested, the ginseng seedlings have grown to more than 65,438+00 cm, and their tolerance to strong light is enhanced, and they can resist direct sunlight and grow in the open field. After the wheat is harvested, the grass is removed and generally not watered.

(3) weeding, thinning and fixing seedlings

Weeds should be removed frequently in the nursery area to prevent lack of grass, weeds should be pulled out when grass is seen in the sowing area, and weeding should be carried out simultaneously in the drilling area. When the height of seedlings is 5 ~ 7 cm, the spacing between plants should be appropriate, and the spacing between plants should be 3 cm, and some over-dense and weak seedlings should be removed in stages. When the seedling height is 9 ~ 12 cm, the seedling spacing should be 10 cm. If there are any missing seedlings, they should be replenished in time.

(4) loosening soil and weeding

For transplanted fields or fields with direct seeding for more than 2 years, loosen the soil and weed in time. Generally, weeds can be weeded 3-4 times in the growing period. Ridge cultivation should be carried out from mid-July to mid-August. After the ground plants wither in late autumn, a shallow weeding should be carried out before ridging. Loose soil should be shallow to avoid damaging the roots. Weeding should be done on cloudy days or in the morning and evening. Every time you water or rain, you should loosen the soil to keep moisture and keep the boundary loose and free from weeds. The management after the embankment is relatively simple, and only a small amount of weeds need to be removed.

(5) Scaffolding

When the seedling height is 30 cm, use branches or thin bamboo poles to stand upright and lead stems and vines to wind, so as to facilitate ventilation and light transmission and promote the growth of Codonopsis pilosula.

(6) Cold protection

When planting Codonopsis pilosula in cold areas, it should be covered with cold-proof soil after partially withering on the ground in late autumn to prevent freezing injury, and it should be pulled out before the winter germination of Codonopsis pilosula in the following spring.

(7) Clean up the countryside

After the aerial part of Codonopsis pilosula withered, the residual stems and leaves should be removed in time, the erection should be removed, and the field disinfection treatment should be carried out with 800 ~ 1000 times of 50% carbendazim solution to reduce the spread of the disease.

(8) Raising seedlings

In low altitude mountainous areas or plain areas, ginseng seedlings can be harvested after one year of seedling raising; In high altitude mountainous areas, seedlings can only be harvested after 2 years of seedling raising. Pay attention to digging from the side when lifting seedlings to prevent seedling injury. Pick up while planing, and remove sick and disabled ginseng seedlings at the same time. Ginseng seedlings are best classified according to large, medium and small, so that they can be planted separately. Sowing should not be carried out in rainy days. Transplanting in autumn, planting after emergence, planting in spring, and storing ginseng seedlings in cellar. Generally, 667 m2 can produce more than 50,000 ginseng seedlings, and 2,000 m2 can be transplanted.