Key Points of Isatis indigotica Planting Technology: Field Management Is Crucial

AbstractSoil: Choose fertile, loose sandy soil as the best option, plow the land more than 30cm deep and apply base fertilizer. Sowing: Can be done in spring or summer; before sowing, the seeds need to be placed in 40°C hot water for about 4 hours for heat treatment. Field management: Timely thinning and pricking out of seedlings, pay attention to weeding and fertilizing. Pest and disease control: The peak period for downy mildew is summer; the peak periods for leaf blight and root rot are around June, and active prevention and control are needed.

1. Soil

Isatis indigotica has low requirements for land and can adapt well to any soil; it is both drought-tolerant and cold-tolerant. However, if you want better planting results, when choosing soil, try to choose fertile, loose, well-draining sandy soil. In addition, for the choice of terrain, flat terrain and a warm, humid environment are preferable.

2. Land Preparation

When planting Isatis indigotica, since it is a deep-rooted plant, it is best to plow the land more than 30cm deep during planting. In addition, it should be handled together with fertilization; after plowing the land well and before sowing, apply fertilizer to the land once.

For the base fertilizer, farmyard manure or chemical fertilizers can be chosen, mainly chemical fertilizers such as phosphate fertilizer, potassium chloride and urea, with an application rate of about 2000kg/mu. When applying fertilizer, mix it thoroughly and evenly with the soil, then level the land, and repair the drainage ditches before starting to plant.

3. Sowing

Isatis indigotica can be sown in 2 seasons, namely March and April in spring and May and June in summer. According to climatic conditions, the north is more suitable for sowing in March and April in spring, while the southern region is suitable for sowing in May and June in summer. When sowing, special attention should be paid: first, place the seeds in hot water above 40 degrees for about 4 hours for heat treatment; during the heat treatment, to make every seed heated evenly, it is necessary to stir constantly.

After the heat treatment is finished, place the seeds in plant ash, stir evenly, and then sow. Before sowing, it is best to use a chemical herbicide for weeding; use alcohol emulsifiable concentrate mixed with water and spray it on the soil surface, then start sowing after 5 days. The sowing method can be drilling or dibbling; when drilling and dibbling, pay attention to the future spacing of each plant. Drilling is about 20cm, and dibbling is about 8cm.

4. Field Management

Management is mainly weeding and fertilizing. After sowing, Isatis indigotica generally emerges in about 15 days. Places without emergence need timely replanting. When the seedlings reach more than 6cm, in order to achieve a spacing of about 8cm between each plant, timely thinning and pricking out of seedlings are also needed. After the seedlings are established, weeding can be carried out. At this time, in order not to affect the quality of Isatis indigotica, it is best not to use chemical herbicides for weeding. For fertilizing, mainly use urea, potassium fertilizer, phosphate fertilizer and plant ash; topdress 3 times a year.

5. Pest and Disease Control

The main pests and diseases of Isatis indigotica are: downy mildew, leaf blight and root rot. The peak period of downy mildew is summer, with symptoms of leaves becoming white or grayish-white and moldy. At this time, drain water promptly to improve soil moisture, and spray an appropriate amount of Bordeaux mixture or mancozeb solution on the leaf surface. The peak periods for leaf blight and root rot are around June. When the disease occurs, pay attention to timely drainage of the field to avoid water accumulation, and at the same time carbendazim can be used for prevention and control.