What are the control methods for pests and diseases of 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 steaming bone syndrome and relieving summer heat, and can treat malaria, with 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 farmers. Let's take a look at the control methods for pests and diseases of sweet wormwood together with the editor below.
1. Damping-off
It 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 shape, and finally cause the seedling to lose support and fall over on the ground. If the ground is wet, white filamentous substances will also appear at the stem base.
Control method: This disease mainly harms seedlings. Generally, the soil or seeds carry the pathogen, which harms seedlings after emergence, so seeds and soil should be disinfected before planting. It generally occurs in March. Before and after the disease occurs, metalaxyl-mancozeb can be sprayed, which has a good preventive and control effect.
2. Stem rot
This disease mainly harms the root and stem parts. After the disease occurs, the leaves on the lower half of the plant begin to turn yellow and dry, the root and stem gradually rot, and black or brown lesions appear at the stem base, slightly sunken, and gradually rot, and finally the plant lodges and dies. This disease is extremely prone to occur under high temperature and high humidity conditions, and its onset is extremely sudden and rapid.
Control method: When the disease occurs, promptly spray a mixed solution of hymexazol and mancozeb, or spray thiophanate-methyl or dimethachlon.
3. Powdery mildew
It is also a fungal disease, generally prone to occur in plots with high temperature, high humidity and poor ventilation. The onset time is generally in summer from June to July. The disease mainly affects leaves and can also spread to stems. When the disease occurs, grayish-white powder appears on the leaves, seriously affecting the photosynthesis of the leaves and causing weak plant growth.
Control method: When the disease occurs, metalaxyl or thiophanate-methyl solution can be sprayed once a week for 2-3 consecutive times, with excellent effect.
4. Cutworms
March is the peak period for cutworms. They hide 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. After the 3rd instar, they hide by day and come out at night. In severe cases, a large number of seedlings die due to missing root systems.
Control method: Adults can be trapped and killed with black light lamps and frequency-vibration insect-killing lamps, and phoxim emulsifiable concentrate can be sprayed on 1st to 3rd instar larvae.
The above is an introduction to the control methods for pests and diseases of sweet wormwood. We hope it can help you. To learn more related knowledge, please follow us.