A Detailed Guide to the Latest Planting Methods for Andrographis paniculata Seeds
Andrographis paniculata is also known as Spring Lotus Autumn Willow, Yijianxi, Olive Pit Lotus, etc. It is an annual herbaceous plant of the genus Andrographis in the Acanthaceae family. As a medicinal herb, it clears heat and detoxifies, reduces inflammation, and relieves swelling and pain. It is commonly cultivated in Fujian, Guangdong, Hainan, Guangxi, and Yunnan in China, and has also been introduced in Jiangsu and Shaanxi. Now let us take a look at how to plant Andrographis paniculata seeds!
Site Selection and Land Preparation
Andrographis paniculata prefers a hot and humid climate. It likes full sunlight and is fond of fertilizer. The suitable temperature for seed germination and seedling growth is 25-30°C. When the temperature drops to 15-20°C, growth slows down; when the temperature drops to around 8°C, growth stops. When exposed to low temperatures around 0°C or frost, the entire plant withers. It is best cultivated in fertile, loose, well-drained acidic and neutral sandy loam soil, though it can still grow normally in alkaline soil with a pH of 8.0.
Seed Treatment
Andrographis paniculata is commonly grown by the seedling transplanting method or the direct seeding method, with the seedling transplanting method being the main approach. When the fruits turn a uniform brown in September to October, pick them in batches before the morning dew dries, place them in a shady spot to after-ripen for a few days, and cover them with a screen to prevent seed loss from bouncing. After the pods have fully split open, sift out the fruit skins to obtain the seeds. Andrographis paniculata seeds are very small, with a thousand-grain weight of 0.93-1.52 grams. The seed coat is hard and covered with a waxy layer, so the sowing technique requirements are relatively high. Before sowing, rub the seeds with fine sandpaper or sand to remove the waxy seed coat, then soak them in warm water, then place them in a 30°C incubator to germinate, and then sow.
Sowing Time
The seedbed soil for Andrographis paniculata should be fertile and loose, raked level and fine. In places such as Guangdong and Fujian, sow in spring from late February to early March, and in autumn sow in July on raised seedbeds. In Jiangsu, Zhejiang, and Sichuan, use hotbeds for seedling raising in mid-to-late March, and cold frames for seedling raising in April. In North China and Northwest China, sow in greenhouses in early-to-mid March, in hotbeds in early April, in sunny cold frames in mid-April, and in plastic tunnels it is best to sow from April 15-20.
Seedbed Management
Seedbed management for Andrographis paniculata mainly involves controlling appropriate temperature and humidity. Before emergence, keep the seedbed moist at all times, and maintain the relative humidity in the bed at 70-80%. After the seedlings emerge completely, soil moisture should be controlled to prevent damping-off disease. When the seedlings are 6-7 cm tall and have 3-4 pairs of true leaves, they can be transplanted. For direct seeding in Jiangsu and Zhejiang, it should not be earlier than mid-to-late April; in Sichuan, mid-April to early May; in Beijing, mid-May is preferable. When cultivating, it is best to divide into two types: seed fields and commercial fields. Seed fields should be transplanted from May to early June, with a row spacing of 50-65 cm and a plant spacing of 30-35 cm. Commercial fields can be planted from late May to early June, with a row spacing of 25-33 cm and a plant spacing of 16-20 cm, planting 105000-195000 plants per square millimeter.
Field Management
Field management for Andrographis paniculata mainly involves timely watering to help the seedlings develop new roots, after which cultivation, weeding, and topdressing are done once every 15-20 days. Topdressing is mainly nitrogen fertilizer, and human and animal manure water, urea, etc. can be applied. Field management is especially important in the three months of June, July, and August, when more nitrogen fertilizer should be applied and watering should be done frequently. When the plants are 30-40 cm tall, soil can be mounded around them to prevent wind damage.
Pest and Disease Control
Diseases of Andrographis paniculata include damping-off, which occurs at the 1-2 pairs of true leaves stage; soil moisture can be reduced, soil can be treated with 50% carbendazim, or the affected area can be drenched with a 1000-fold solution. Seedling blight occurs at the 2-3 pairs of true leaves stage; temperature can be controlled, ventilation can be ensured, and seedbed management can be strengthened. Black stem disease occurs at the mature plant stage; field management can be strengthened, waterlogging should be drained promptly, continuous cropping should be avoided, and during the onset period, a 50% carbendazim 1000-fold solution can be sprayed or used to drench the affected area. For phytophthora disease, a 50% carbendazim 1000-fold solution can be sprayed or used for shallow irrigation of the affected area. Pests include cotton bollworm, mole crickets, and others.