How to grow Isatis indigotica? A detailed explanation of the key cultivation techniques in one article
We are no strangers to the term Isatis indigotica, but we are actually not very familiar with this medicinal herb. Its stems, leaves, and roots can all be used as medicine, and some also call it woad or Daqingye. It is mainly used to clear heat and detoxify, and to prevent colds, and it is grown in all regions of our country, so how do you grow Isatis indigotica? Then today let us take a look at its key cultivation techniques.
1. Deep plowing of the land
The land for growing Isatis indigotica generally needs to be deep plowed at least about 30 cm. It is a deep-rooted plant and is suitable for growing in warm, humid environments, but it also has the characteristics of being drought resistant, cold tolerant, afraid of waterlogging, and intolerant of standing water. Therefore, the place where Isatis indigotica is grown generally has loose soil, is close to a water source but has good drainage conditions, and has sufficient soil fertility. Deep plow the land and combine it with fertilization. The base fertilizer is mainly farmyard manure, mixed evenly, and then water ditches are opened, ready for planting.
2. Sowing time
Isatis indigotica can be sown in the two seasons of spring and summer. Spring is generally around March or April, and summer is May or June, but in northern regions it is more suitable to plant in spring. Before sowing, we need to put the seeds into hot water of more than 40 degrees to scald them, and stir constantly so that they are heated evenly. After four hours, remove them, put them into plant ash and mix evenly, and then they can be sown. Sowing generally uses the methods of drilling or dibbling. The row spacing is generally about 20 cm, and the seeds are spread evenly and covered with soil. For dibbling, attention should be paid to the spacing between each plant, generally about 8 cm is suitable.
3. Field management
About one week after sowing, Isatis indigotica will basically emerge. In about half a month, the Isatis indigotica seedlings in the field will be fully emerged. If they have not emerged after half a month, then the only option is to replant the seedlings. When the seedlings grow to about 6 to 7 cm tall, thinning, replanting, and evening out of the seedlings can be carried out. Ensure that the spacing between each plant is about 6 to 8 cm, and at the same time 2 to 3 seedlings can be kept per plant. After the seedlings are established, intertillage and weeding are needed. It is generally not recommended to use chemical agents for weeding, as this will affect the quality of Isatis indigotica. If the main purpose is to harvest Isatis indigotica, then topdressing generally only needs to be done three times each year, mainly with urea, to promote the growth of the stems and leaves of Isatis indigotica. But if the purpose is to harvest the roots, then on the basis of three topdressings, we also need to apply potassium fertilizer and phosphate fertilizer once, and apply them together with plant ash, which can promote the thickening of the roots.
4. Control methods
The prevention and control of pests and diseases is a difficult point in the cultivation techniques of Isatis indigotica, because it is a Chinese medicinal herb, and excessive use of pesticides for control will affect the quality of Isatis indigotica. The main pests and diseases of Isatis indigotica include downy mildew, leaf blight, root rot, and so on. Downy mildew generally begins to occur around March or April, and the peak period of occurrence is from June to August. We can prevent and control it by reducing moisture and controlling the amount of nitrogen fertilizer used, and when necessary, spray with mancozeb for control. Leaf blight and root rot can be controlled with carbendazim. The most common insect pest is the cabbage butterfly, which mainly damages the leaf surface of Isatis indigotica, and the peak period of occurrence is around June, and pyrethroid pesticides can be used for spraying and killing.
The editor reminds everyone here that when planting, you must master the key points of cultivation. Secondly, when using chemical agents for control, it must be done within half a month to one month before harvest, so as not to affect quality.