Cultivation techniques under Asarum Forest in Northeast China

Northeast Asarum (northern Asarum, Liao Asarum), Aristolochaceae Asarum perennial herbs, dried whole herbs used as medicine. It has the effect of dispelling wind and dispelling cold, dredging orifices and relieving pain, warming lung and resolving phlegm. Most of them are distributed in the eastern mountain areas of the three northeastern provinces.

1. Biological characteristics

1.1 growth and development

Asarum mandshurica is a perennial herb, which usually takes 7 years from sowing to new seed formation, and then blossoms and bears fruit year after year. Asarum flowers and leaves bloom in early spring in a year, and the aboveground plants basically grow in May, no longer grow, and do not pull out new leaves. The spores differentiate in July, form complete overwintering buds in autumn, and grow and develop again in the second year.

1.2 Biological characteristics of seeds

1.2.1 the life span of seeds is short. The germination rate of naturally mature seeds is more than 95%; the germination rate is about 80% after storage at room temperature and dry for 20 days; the germination rate is about 29% after 40 days; and the germination rate is 2% after 60 days. Thus it can be seen that the germination rate of dry storage of seeds decreases gradually with the extension of storage period, and when the storage period is more than 60 days, the vigor will be completely lost. Therefore, the seeds should be sowed immediately after seed collection, and those who cannot be sowed in time for some reason should be buried in wet sand (1 part of seed mixed with 3 parts of river sand) for storage. After 2 months of preservation of wet sand, the germination rate is still more than 80%, and this method can also be used to transport seeds over a long distance.

1.2.2 the relationship between growth and development and environmental conditions. The main results are as follows: (1) temperature: under the condition of 20 ℃ and 24 ℃, the seeds are suitable for humidity, complete morphology and ripening in about 50 days, germinate and take root at 17 ℃, and the rooting seeds can germinate after 50 days under the condition of 5 ℃. The field surface temperature was 10 ℃ 12 ℃ and began to blossom at 17 ℃. It could withstand severe cold of-40 mol in dormant period. (2) Water and fertilizer: Asarum mandshurica is a fibrous medicinal plant. When the seeds germinate, the soil water content should be 30%. During the growth period, the seedlings are afraid of water, and the seedlings are afraid of drought. The seedling emergence rate is low, and the seedling preservation rate is also low; (3) Light: Asarum is a negative medicinal plant, seeds need light before direct seeding to emergence. The seedlings should be shaded for 1-2 years, and the canopy density of under-forest cultivation should be controlled at 0.6 ~ 0.7. The canopy density of 3-4-year-old seedlings should be controlled at 0.3 ~ 0.4.

2. Cultivation techniques.

2.1 Land selection and preparation

Asarum prefers warm, cool, moist environment and humus-rich well-drained loam or sandy loam. The soil layer of the plot should be deep, and the soil should be loose, fertile and moist. The slope of woodland should be below 15 °. When raising seedlings under the forest, flat broad-leaved woodland with sparse trees should be selected. Combined with forest cultivation, the trees that can be cut down on the bed should be cut down, the distance between the beds should be appropriately relaxed, all the trees between the beds should be retained, and the crowns can be properly thinned in places that are too dense. The bed should be inclined to the mountain and avoid due south and north as far as possible. After selecting the land, ploughing and turning, the depth is about 20cm. After crushing the soil, pick out tree roots, weeds, stones and other sundries, and then make beds. The general bed width is 1.2m and the height is 15-20cm. The bed surface is required to be flat and the bed spacing is 50-80cm.

2.2 sowing and transplanting

2.2.1 seed live broadcast

2.2.1.1 seed collection: the fruit matures in the middle and late June and should be picked along with ripening. Generally speaking, the fruit ripens quickly in cloudy and rainy days and should be harvested in time. The picked fruit should be placed in a cool place for 3 days. When the peel becomes soft and powdered, you can rub the peel and pulp, rinse the seeds with water, dry them in a cool place, and sow seeds while they are fresh.

2.2.2.2 sowing: it is usually from the first ten days of July to the middle of July, and it is not suitable to pass the first ten days of August at the latest. There are two sowing methods: sowing and strip sowing. (1) sowing: a shallow trench with 3-5cm depth was dug on the surface of the bed, and the bottom of the ditch was paved with fine humus sifted, and then sown. When sowing, the seeds should be mixed with 10 times of fine sand or humus to spread evenly. After sowing, 0.5-1.0cm was covered with fine humus sifted. Cover the bed with fallen leaves after being covered with soil. The amount of sowing fresh seeds is about 120-140g/m2. (2) strip sowing: the horizontal bed was trenched with 3-5cm deep shallow trench, row spacing 10cm, ditch width 5-6cm, the bottom of the trench was leveled and slightly compacted, then sown in the wide trench, covered with 0.5-1cm, and finally covered with deciduous leaves, and the amount of fresh seeds sown was about 100g/m2. (3) Seedling field management: in the spring of the second year after sowing, when the bed soil is thawed, remove the mulch and water it in time in case of drought. Although Asarum is a negative plant, it still needs some light during its growth and development. generally, the light resistance of 1-2-year-old is weak, shading can be slightly larger, canopy density is 0.6-0.7, and 3-4-year-old is strong, canopy density is 0.4.

2.2.2 Seedling and transplanting

The 2-3-year-old seedlings are dug up every October and planted in three categories: big, medium and small. When planting, the horizontal bed is ditched, the row spacing is 15cm, the furrow depth is 9-10cm, and the plant spacing is 8-10cm, so that the fibrous root is stretched and the soil is covered with 3-5cm. Transplanting in spring and spring should be carried out before spores germinate. Seedling field management is the same as seed direct seeding.

2.3 Disease and pest control

2.3.1 Sclerotinia sclerotiorum is the main disease of Asarum. It spreads quickly and does serious harm. Source of disease: mainly caused by seeds, seedlings and pathogenic soil with pathogens. Generally, diseased plants appear first in the field, and then spread and expand, forming disease spots, beds and disease areas. Route of transmission: mainly human activities. In addition, pests and rodents also play a role in transmission. Air can't spread. Therefore, under natural conditions, the disease spreads slowly and spreads quickly by man. After the formation of diseased field, the whole plough layer is occupied by bacteria, and the formation of permanent diseased field, it is difficult to prevent and cure. Prevention and control measures: (1) investigation in the production area: it is found that the disease area is strictly blocked, the transportation of disease species and seedlings is prohibited, and man-made transmission is prevented. The ward and sickbed should be thoroughly cured. (2) to establish a base for disease-free seeds and seedlings. (3) Disinfection of seeds, seedlings and utensils: use the mixture of 800 times of ammonium benzoate and 200 times of 10% carbendazim to soak seeds and seedlings for 4 hours respectively. Do not select injured seeds and seedlings when sowing, planting, transplanting and disinfection to prevent drug damage. (4) Chemical control: the disease areas and diseased plants were ditched with the above solution to infuse the disease-free plants around the diseased plants and the plants sprayed on the ground. It was carried out about 5 times from the beginning of April to the end of May and from the beginning of September to the end of October.

2.3.2 insect pests (1) small tigers: bite buds, truncate petioles and rhizomes. Prevention and control: trap and kill with poisonous soil and bait. (2) the larva of Asarum butterfly, Dendrolimus punctatus: mainly bites leaves. Control: spray 0.1% wettable trichlorfon on the leaf.

3. Harvesting and processing

3.1 harvesting

The seeds of Asarum mandshurica were harvested for 3-5 years, seedlings and transplanting plots, and harvested for 3-4 years. It is usually harvested in August.

3.2 processing

After Asarum harvest, remove the soil, 1 for every 10 plants, and dry in a cool and ventilated place. It cannot be washed or insolated. The leaves blackened after washing dry. The roots are white. The leaves turn yellow after the sun, which reduces the smell and affects the quality.