How to prevent the blight of Artemisia annua

Chrysanthemum (Chrysanthemum coronarium L.) Also known as Artemisia annua, chrysanthemum cauliflower, Artemisia annua, Artemisia seed, cauliflower (also known as goose cauliflower in Fujian and other places), for Compositae annual or biennial herbs, leaves alternate, long-pinnately divided, flowers yellow or white, very similar to wild chrysanthemum. Achene edge, two or three feet high, stems and leaves can be eaten when tender, can also be used as medicine.

Growth habits of Artemisia annua L.

Chrysanthemum chrysanthemum is a semi-cold-tolerant vegetable, which is not strict with light, and weak light is generally better. It is a short-day vegetable, which is beneficial to its growth when it is cool and mild, and the soil relative humidity is maintained at 70% to 80%. Under the condition of long-day sunshine, vegetative growth can not be fully developed, and it will soon enter reproductive growth and blossom and seed.

Geographical distribution of Artemisia annua L.

Native to the Mediterranean, it has been cultivated in China for more than 900 years, and it is widely distributed, but the cultivated area in the north and south is very small. Distributed in Anhui, Fujian, Guangdong, Guangxi, Guangzhou, Hainan, Hebei Shijiazhuang, Hubei, Hunan, Jilin, Shandong, Jiangsu and other provinces.

How to prevent chrysanthemum blight?

What is chrysanthemum blight?

The disease of Artemisia annua is mainly harmful to the root and rhizome, and the initial part of the disease is light brown to brown water-stained oval disease spot. after the depression of the disease part, the diseased stem gradually shrinks or withered, and the diseased seedlings begin to wilt, and then gradually wither, but the diseased plants stand but do not fall, so it is called standing blight.

Harmful symptoms of chrysanthemum blight:

The disease of Artemisia annua is mainly harmful to the root and rhizome, and the initial part of the disease is light brown to brown water-stained oval disease spot. after the depression of the disease part, the diseased stem gradually shrinks or withered, and the diseased seedlings begin to wilt, and then gradually wither, but the diseased plants stand but do not fall, so it is called standing blight. Under the condition of high humidity, the disease often grows light brown and sparse arachnoid mold, and the disease spreads slowly on the seedling bed.

The transmission route and incidence conditions of Artemisia annua blight:

It overwinters in the soil with mycelium or sclerotia, and can saprophyte in the soil for 2-3 years. The hyphae can directly invade the host and spread through water flow and farm tools. The development temperature of the pathogen was 24 ℃, the highest was 40 ~ 42 ℃, the lowest was 13 ~ 15 ℃, and the suitable pH3~9.5. The disease can be easily induced by over-dense sowing, untimely seedlings and high temperature.

Prevention and control of blight of Artemisia annua L.

The main results are as follows: 1) strengthen the management of nursery bed, release air scientifically, and prevent the occurrence of high temperature and humidity in seedbed or seedling tray.

2) spraying phytonin 7500-9000 times or 0.1% potassium dihydrogen phosphate at seedling stage can enhance disease resistance.

3) mix seeds with 40% of 0.2% seed weight.

4) treatment of medicine and soil in seedling bed or seedling tray. You can use 40% seed mixing double powder alone, or you can use 40% seed mixture mixed with Fumishuang at 1:1, 8 grams per square meter of seedbed. The treatment method of medicine and soil is the same as sudden collapse disease. In the single incidence area of blight disease, the control effect of mixed seed Ling alone is not high, it must be mixed with the same amount of Fu and the United States can be effective. The chlorination bitter film method can also be used, that is, after the whole bed, 2-4 mm of chloropicrin is deeply applied to 10-15 cm every 30 cm, and the soil is covered while applying. After all application, the border is covered with plastic film, and then sown and planted after 12-15 days.

5) the initial stage of the disease was sprayed with 1200 times of 20% methyl rifampicin EC (lique bacteria), or 5% Jinggangmycin water agent 1500 times, 10% rikuling water suspension, 15% carbendazim water solution, 23.5 liters per square meter. When quenching disease and blight mixed, 72.2% Pulicol water agent 800 times liquid plus 50% thiram wettable powder 800 times liquid can be sprayed, 2-3 liters per square meter. Plant growth regulator-transplanting Ling mixture can also be tried. According to the disease, once every 7 to 10 days, prevention and treatment for 2 or 3 times in succession.

6) Biological control. Antagonistic microorganisms were used for biological control. Wu's pig manure composting culture antagonistic bacteria Bacillus cereas for soil, seed and reproductive weaving treatment can control bacterial blight.

7) the fruit close to the ground is prone to Rhizoctonia fruit rot, so it is best to use grass rope to make a circle to cushion the melon, or you can spray the above fungicides for prevention and control. In addition, you can also choose 15% Xiaoling (instead of copper preparation) water agent 600 times liquid, 45% soil bacteria water repellent 450 times liquid, 80% Xinwansheng wettable powder 600 times liquid.

8) seed coating was used. Using seed coating agent 9Mel 2, the seed coating technology takes the seed as the carrier, and the highly efficient internal absorption fungicide, insecticide, trace elements and hormones are coated on the seed surface with the help of film-forming agent to quickly solidify into a drug film that is not easy to fall off. after seed sowing, the effective components on water absorption germination, emergence, growth, seed coating agent are gradually absorbed by the root and transmitted to all parts of the plant, which can control germs, pests and mice on the ground and below. Cucumber seed coating agent 9mai 2 is effective on vegetables and melons. The amount used is 0.5% of the seed weight (effective component), which translates into a commodity quantity of (0.5 × 100) / 20 × 2.5g ≈ 2.5g (ml), which means that 2.5ml can be mixed with 100g seeds. The effective concentration of the commodity is 20%.