Detailed Guide to Andrographis paniculata Cultivation: Key Management Points from Sowing to Harvest

Andrographis paniculata, also known as lanhe lian or yijianxi, is a plant of the Acanthaceae family. The whole plant is used as medicine, and it has effects such as clearing heat and detoxifying, reducing inflammation, and reducing swelling and relieving pain. It is one of the Chinese herbal medicine varieties suitable for cultivation in Guangxi with relatively high economic value. The key cultivation and management techniques are as follows:

I. Seedling propagation. Because Andrographis paniculata seeds are tiny and the seedlings have poor emergence ability, the seedbed soil needs to be deep-plowed 2—3 times and the soil clods broken up, then beds are made. For every 30 sq m of seedbed, apply 200 kg of fully fermented and decomposed manure, mix the manure and soil thoroughly, then level the bed surface. The sowing time is chosen around Qingming Festival. Before sowing, first soak the seeds in warm water at 40—45°C for 1—2 days (or treat by mixing with fine sand to scratch the seed coat). When sowing, scoop out the seeds, mix them with plant ash, and broadcast them on the seedbed, then spread a layer of fine soil about 3 mm thick, and immediately sprinkle clear water with a sprayer so that the soil is thoroughly wet. After sowing, cover with agricultural film, and then cover the film with a layer of rice straw to keep warm and retain moisture. The sowing rate is preferably 50—60 g per 30 sq m of seedbed (the seedlings cultivated can be enough for transplanting to 1—2 mu of field). When 50%—70% of the seedbed has sprouted, promptly remove the film and straw that are close to the ground. After emergence, combine with watering and apply diluted manure water once every 7 days to promote rapid seedling growth.

II. Field land preparation. Before transplanting, select mountain land or flat land with a soil pH between 5.6—7.4, flat terrain, sheltered from wind and facing the sun, fertile and loose, and convenient for irrigation and drainage as the transplanting field. The field should be deep-plowed, and for every mu apply 2,000 kg of decomposed pig and cattle manure and 20 kg of calcium magnesium phosphate fertilizer as base fertilizer, then rake level and make beds 120—130 cm wide and 15—20 cm high, with 30 cm deep irrigation and drainage ditches dug around the field.

III. Transplanting and planting. One month after sowing and raising seedlings of Andrographis paniculata, when the seedlings are 10 cm tall and have 4—5 pairs of true leaves, they can be transplanted to the planting field. One day before transplanting, first irrigate the nursery land thoroughly, select robust seedlings from the seedbed and transplant them with soil. The row and plant spacing for planting is about 20×20 cm, and 12,000 plants are planted per mu. One week after transplanting the seedlings, apply a light manure water once to promote root establishment and growth.

IV. Field management. First, manage water well. Andrographis paniculata likes moisture and fears drought, and is sensitive to water. It should be kept moist frequently, but not excessively wet. The key point of seedling stage management is to keep the bed surface moist. After transplanting, if there is no rain, generally water 1—2 times a day; after the seedlings recover, the ground still needs to be kept moist, watering once every 3—7 days. Second, manage topdressing well. The production of Andrographis paniculata requires a large amount of nitrogen fertilizer, so topdressing must be applied in a timely manner. Generally, topdressing is required 3 times. After the seedlings recover, apply 3,000 kg of diluted human manure and urine or 10 kg of urea per mu to promote seedlings. After that, apply topdressing once every 20—30 days, with 15—20 kg of ammonium sulfate or other nitrogen fertilizer per mu. After the plants close the rows, fertilizer can be applied with irrigation water. Third, pinch the tops and earth up. Since the whole plant of Andrographis paniculata is used as medicine, when the seedlings are about 30 cm tall, remove the top to promote the growth of side buds; at the same time, combine with intertillage to earth up and weed, promoting the growth of adventitious roots to prevent lodging. If seeds are to be kept, do not pinch the tops during full flowering, and at the same time remove the inflorescences that cannot set fruit and mature. Fourth, manage pest and disease control well. For seedling damping-off, spray with 50% thiophanate-methyl wettable powder at 1,000 times dilution for control; for mole crickets, lamp moth larvae, and small cutworms, spray with 90% trichlorfon at 1,000 times dilution for control.

V. Harvesting and processing. When Andrographis paniculata grows to the flowering and budding stage, it can be harvested. At harvest, use a sickle to cut at 2—3 nodes from the stem base and dry it in the sun. Planting Andrographis paniculata can yield two harvests a year, and the annual dry yield per mu can reach 500—800 kg. The dried Andrographis paniculata after harvesting and sun-drying is considered superior when it is dry, green in color, has many leaves, and is free of impurities and mildew.