A Detailed Guide to the Latest Pest and Disease Control Methods for Sweet Wormwood

Sweet wormwood, also known by its scientific name Artemisia annua, with aliases such as stinking wormwood, fragrant wormwood, and bitter wormwood, is an annual short-day herbaceous plant and also a traditional Chinese medicinal herb. It has the effects of clearing deficiency heat, eliminating bone-steaming, and relieving summer heat, can treat malaria, and has extremely high medicinal value. At present, it is also cultivated artificially, but during cultivation, pests and diseases seriously affect yield and quality, causing economic losses to medicinal herb growers. Now, follow the editor to take a look at the control methods for sweet wormwood pests and diseases.

1. Damping-off

This is a fungal disease, and the pathogen is Rhizoctonia solani. It mainly harms seedlings. When the disease occurs, water-soaked lesions appear at the base of the seedling stem, spread around the stem, gradually constrict into a thin thread-like shape, and finally cause the seedling to lose support and fall over onto the ground. If the ground is damp, white thread-like material will also appear at the stem base.

Control methods: This disease mainly harms seedlings. Generally, the soil or seeds carry the pathogen, and it harms seedlings after emergence, so before planting, seeds and soil should be properly disinfected. It usually occurs in March. Before and after the onset of the disease, metalaxyl-mancozeb can be sprayed, which has a relatively good preventive and control effect.

2. Stem rot

This disease mainly harms the root and stem area. After the disease occurs, the leaves on the lower half of the plant begin to turn yellow and dry, the roots and stems gradually rot, and black or brown lesions appear at the stem base, slightly sunken, and gradually rot, finally causing the plant to lodge and die. This disease is very likely to break out under high temperature and high humidity, and its onset is extremely sudden and rapid.

Control methods: When the disease occurs, promptly spray a mixed solution of hymexazol and mancozeb, or spray thiophanate-methyl or dimethachlon.

3. Powdery mildew

This is also a fungal disease. It is generally prone to occur in plots with high temperature and high humidity and poor ventilation. The onset time is generally in summer from June to July. The disease mainly affects the leaves and will also spread to the stems. When the disease occurs, gray-white powder appears on the leaves, seriously affecting leaf photosynthesis and causing weak plant growth.

Control methods: When the disease occurs, spray metalaxyl or thiophanate-methyl solution once a week for 2-3 consecutive times, and the effect is excellent.

4. Cutworms

March is the peak period for cutworms. They lurk in the soil and feed on the roots and stems of seedlings, often biting seedlings off. Young larvae are active all day and are not easy to detect, while after the 3rd instar they hide by day and come out at night. In severe cases, a large number of seedlings wither and die due to missing root systems.

Control methods: Adults can be trapped and killed with black light lamps or frequency-vibration insect-killing lamps, and phoxim emulsifiable concentrate can be sprayed on 1st-3rd instar larvae.

The above is an introduction to the control methods for sweet wormwood pests and diseases. We hope it can help you. If you want to learn more related knowledge, please stay tuned to us.