How to grow sweet wormwood from seed? Detailed explanation of sowing methods and techniques
Sweet wormwood (Artemisia annua) is an annual herbaceous plant of the genus Artemisia in the Asteraceae family. Its full growth period is about 120 days. It prefers moisture, avoids drought, and fears waterlogging. It requires sufficient light and has very high medicinal value. The derivatives of its extract artemisinin can be used to produce many series of medicines. Moreover, the crop is easy to grow and manage, with a short growth period, low investment, and quick returns. Let's take a look below at how to grow sweet wormwood from seed!
Seed collection and land preparation
Sweet wormwood seeds are collected in September to October. The successively maturing seed plants are cut back and dried, the seeds shaken off, the seed shells and impurities removed, and the seeds stored for later use. Sowing is done in mid-February. Before sowing, choose sunny, moist alluvial soil, preferably at an altitude of 600 to 750 m. First apply 2000 to 2500 kg of organic fertilizer per mu onto the chosen ground, then plow the land, turn the applied base fertilizer into the soil, cultivate finely and level it, and make raised beds 1.3 m high, with the beds oriented east-west and the bed height 20 cm.
Sowing and raising seedlings
Before sowing sweet wormwood, first mix the seeds with ash to form seed ash, sprinkle evenly over the bed surface, then thinly cover with a layer of plant ash, just enough to cover the seeds. After emergence, pay attention to drought prevention and seedling protection. During the seedling stage, topdress with light human and livestock manure water, 800 kg per mu. When the plants are 5 to 10 cm tall, they can be transplanted. The seeding rate per mu of seedling land is 100 to 150 g, which can yield 280,000 to 300,000 transplantable seedlings, enough to plant 2.67 hectares of land.
Land preparation and transplanting
For the sweet wormwood transplanting site, use 2000 to 2500 kg of farmyard manure or cattle and horse stable manure per mu, add 100 to 150 kg of superphosphate, mix well, broadcast over the ground, turn into the soil, and cultivate finely and level. Make raised beds 1.3 m high with trenches 10 to 15 cm deep, with the beds oriented north-south, and then planting can begin. Dig holes in the beds at a plant and row spacing of 26.5×26.5 cm, plant 1 plant per hole, using 7500 to 12000 seedlings per mu. If wide-narrow row planting is used, ginger can be interplanted within the rows, or corn can be sown at 0.8×1.2 m, and sweet wormwood can be planted in the wide rows of corn at 40×60 cm.
Field management
From transplanting to harvest, sweet wormwood must be weeded 2 to 3 times. Topdressing is carried out together with weeding, and foliar topdressing can also be applied 1 to 2 times. The first time, after the seedlings survive, carry out shallow hoeing. After hoeing, use 1000 to 1500 kg of light human and livestock manure water, 3 to 5 kg of urea, and 2 to 3 kg of superphosphate per mu, mix evenly, and apply into the holes. The second time, before row closure, carry out intertillage and weeding once. After weeding, use 1000 to 1500 kg of human and livestock manure water, 10 kg of urea, 30 kg of superphosphate, and 10 kg of potassium chloride per mu, and apply evenly into the holes. When sweet wormwood grows to 1 m tall, pinch off the tender tip of the top 0.5 cm to promote more lateral branching and increase yield.
Pest and disease control
The main disease of sweet wormwood is powdery mildew, also known as wax gourd powdery mildew. It occurs in June to July and mainly harms the leaves. The disease develops from old leaves to new leaves, with powdery mildew covering the entire leaf, which is the ascocarp of the pathogen. When the disease occurs, spray 2 to 3 times with 0.3 degrees Baume lime-sulfur mixture, or use wettable triadimefon diluted 500 to 800 times with water for spray control. The main insect pest of sweet wormwood is aphids, which harm the tender shoots. Use 40% dimethoate emulsifiable concentrate at 1000 times dilution for spray control.
Harvesting and processing
Sweet wormwood can be harvested at the budding stage in July to August of the year of transplanting, because the artemisinin content at the budding stage reaches 0.986 to 1%, which is the suitable harvest period. At harvest, cut down the whole plant and sun-dry it, use a wooden stick or mat cover to beat off the dry leaves, pick out impurities, stems, and branches, and store in a ventilated and dry place for later use. The dried leaves of sweet wormwood can be directly used as medicine in measured amounts in traditional Chinese medicine formulas. If extracting artemisinin, package immediately after the leaves are dry and transport to the pharmaceutical factory to extract its active ingredients according to a certain process flow.