Cultivation and management techniques of rehmannia

Rehmannia glutinosa to Wenxian, Wuling, Mengzhou and other places with the largest yield, the best texture, known as Huaidihuang.

Growth habit

Rehmannia glutinosa is wild on hillsides, roadsides and fields. It likes mild climate and needs plenty of sunlight. The root tuber grows rapidly when the temperature is 25 ℃ ~ 28 ℃. The soil is not strict, and fertile clay can also be planted. Cold resistance, drought tolerance, like fertilizer, afraid of stagnant water, avoid continuous cropping. The growth and development can be divided into four stages: seedling stage (from seedling emergence to 10 cm in diameter, 4 ~ 6 months), panicle stage (rapid growth of leaves, June ~ July), root expansion stage (slow growth of leaves and rapid expansion of root tubers, July ~ September), and mature harvest stage (aboveground growth stopped in October). Rehmannia glutinosa, which overwintered that year, blossomed in April the following year, and the fruit matured in June.

Cultivation techniques

First, land selection and land preparation. It is appropriate to select the land with open, sunny and low groundwater level, and the sandy loam with loose, fertile and good drainage is better. Wheat, corn and other gramineous crops are suitable for the previous crop. After harvest before autumn, deep ploughing is about 30 cm. In the spring of the following year, each mu of barnyard manure 4000-5000 kg, superphosphate 50 kg, cake fertilizer 50-100 kg, evenly sprinkled on the ground (preferably trench application), and then shallow ploughing, rake fine leveling, to make 1.2 meters wide flat or high border, can also be 60 cm high ridge.

Second, the method of reproduction. Because there are many bud eyes on the root of Rehmannia glutinosa, it is easy to take root and sprout, so it can be propagated with tuber and seeds (mostly for breeding).

1. Root propagation. After the harvest of Rehmannia glutinosa in autumn, the root tubers, which are pest-free and in good shape, with a diameter of 1 cm to 2 cm, are selected and planted in the cellar. You can also choose to keep some of the well-grown ones that year without digging, stay in the open field for the winter, and planing and planting in the spring of the following year. Due to the different climatic conditions and varieties, the planting time is also different, but it can be divided into early Rehmannia glutinosa and late Rehmannia glutinosa. Early Rehmannia glutinosa is planted in the first and middle of April and late Rehmannia glutinosa is planted from late May to early June. When planting, on the whole border surface, trench according to the row spacing of 30 cm, put the rhizome according to the plant spacing of 15 cm and 20 cm, and cover the soil with a thickness of 3 cm and 4 cm. About 40 kilograms of roots need to be planted per mu.

2. Seed propagation. The method of seedling transplanting was mostly used, and the seedlings were sowed and raised in late March. Sow in shallow trenches with a row spacing of 10 cm and 15 cm, and cover soil with a thickness of 0.3 cm and 0.5 cm. Always spray water to moisturize. Seedlings can emerge 15 days after sowing. When the seedlings have 6 or 8 leaves, they can be transplanted to the field. According to the row spacing of 20 cm, plant spacing of 15 cm transplanting, autumn mining, the big can be used as medicine, the small select strong, substantial seed. After continuous selective propagation, the yield and quality of Rehmannia glutinosa root are better than those of asexual propagation for many years. The two propagation methods should be used alternately to prevent degradation.

Field management Rehmannia glutinosa root shallow, to shallow hoe, so as not to hurt the root. Generally, there are three shallow hoes before closing the line, and the last one is a little deeper. Combined with mid-tillage, 2000 kg of human feces and urine and 50 kg of cake fertilizer were applied per mu for the first time, and 2500 kg of human feces and urine, 50 kg of cake fertilizer and 50 kg of calcium superphosphate were applied per mu for the second time (if the base fertilizer had been applied, calcium superphosphate and cake fertilizer should not be applied or less). Before closing the line, you can also add some phosphate fertilizer for the third time according to the second amount of topdressing. Watering less, watering frequently, do not flood. In the rainy season, stagnant water in the fields should be removed in time to prevent rotting roots. In addition to the plants that leave seeds, the flowers should be removed in time. Rehmannia glutinosa can grow slender roots along the surface at the root tuber, which is called a string of bark roots, which should be completely removed.