There are two varieties of chrysanthemum, north and south. Chrysanthemum morifolium planted in the south is heat-resistant and cold-resistant; Artemisia selengensis planted in the north is Artemisia selengensis, which has strong cold resistance and poor heat resistance. Different varieties, different regions, planting stubble and management methods are different. As a northerner, I will talk about how to plant and manage Artemisia microphylla in the north.

I. Habitat of Artemisia microphylla. 1, Chrysanthemum morifolium, also known as Chrysanthemum morifolium, is a semi-cold-tolerant vegetable, which likes cold and warm climate and is afraid of heat. Seeds can germinate at 10℃, the suitable growth temperature is 17~20℃, and plants can tolerate 65438 in a short time.

2. Saussurea microphylla doesn't have strict requirements on light and is resistant to weak light. Under the condition of high temperature and long sunshine in summer, the plants grow poorly, and they will bolt and bloom before they grow much. However, Artemisia selengensis belongs to a long-day plant, and it rarely bolting and flowering when cultivated in solar greenhouse or spring.

3. Anyone who has planted Artemisia microphylla knows that Artemisia microphylla has a thin and short root system, belongs to shallow-rooted vegetables, grows rapidly, is not drought-tolerant, and needs adequate water supply. Therefore, when planting Chrysanthemum morifolium, the soil must always be moist, the humidity should be about 75%, and the air humidity should be 90%. Such moisture and humidity can ensure the fresh and tender texture of chrysanthemum.

4. Artemisia selengensis requires fertile soil with a pH of 5.5-6.8. Because of its short growth period, it mainly produces stems and leaves, so the demand for soil nutrition is mainly available nitrogen fertilizer.

Get a general understanding of the habitat of Artemisia selengensis, and you will understand that Artemisia selengensis can be planted all year round according to the current planting mode. Protected land can be used for planting in spring 65438+ 10 in advance, or planted in the open air in March. It can be planted in alpine regions in summer and in August ~ 65438+10 in autumn. In winter, it can be cultivated in efficient and energy-saving sunlight greenhouse or plastic greenhouse. Therefore, there is no strict requirement on the sowing date of Chrysanthemum morifolium, as long as it is suitable according to its habitat and conditions, it can be planted at any time, but it should be treated differently according to the different planting conditions. Now that the Spring Festival is coming, I will talk about the time for planting chrysanthemums in plastic greenhouses in northern China: June 5438- 10, and the time for planting chrysanthemums in winter: the end of the year-March in spring. How to cultivate and manage? You can make a good profit in the vegetable off-season market.

Second, the main points of autumn sowing in plastic greenhouses. 1, seed selection: choose high-quality chrysanthemum varieties with strong cold tolerance, fast growth and early maturity. The sowing date is generally one month later than that of chrysanthemum planted in the open field in autumn, and it is usually sown in plastic shed at the end of 10.

2. Soil preparation: remove all residual plants on the ground in the shed. We uncovered the plastic film covering the shed, plowed it for 20㎝, sun it for about 4 days, applied about 2800 decomposed organic fertilizer per mu, and leveled the ridges after shallow tillage and fine harrowing. 20 days before sowing, spray 40% formalin 100 times of liquid evenly into the soil, about 3L per square meter of liquid medicine, cover the soil with plastic film for 5 days for disinfection, remove the plastic film and loosen the soil again, and sow after 10 days, which can prevent Artemisia from lodging.

3. Sowing: First soak the seeds in warm water at 30℃ for 24 hours, take them out and wash them with clear water, and screen out impurities and floating shriveled seeds. Then put the seeds at the temperature of about 65438 08℃ to accelerate germination, and wash them with clear water once a day. When the seeds are about 65% white, they can be planted. According to the line spacing of about 1.6 ㎝, open a furrow with a width of about 6.5㎝ and a depth of about 1.8㎝. After the seeds are sown evenly, cover the soil and pour enough water.

Third, field management: 1, greenhouse cultivation in late autumn, Artemisia selengensis growing season in winter, mainly to prevent freezing injury. When the temperature drops below 12℃, we will put up a shed to keep warm. Before the film is buckled, a week after sowing, the seedlings of Artemisia selengensis will come out together, interplanting two real leaves, and then interplanting three real leaves to remove the weakness and retain the strength. Seedling spacing is 4㎝, combined with weeding, combined with watering and topdressing urea10 ? per mu.

2. When the temperature in the shed exceeds 25℃ during the day, it should be ventilated in time. When the temperature is lower than 8℃ at night, it is necessary to cover thermal insulation equipment such as straw curtains to keep the seedling temperature at about 65438 02℃. After 40 days of sowing, the growth rate of seedlings was accelerated, and the height of seedlings was greater than 10㎝. On a sunny morning, combined with watering and topdressing, urea per mu is10. After watering and topdressing, pay attention to ventilation and dehumidification in the shed to prevent diseases.

Fourth, harvest and topdressing. Usually in the month of 65438+February, when the height of Artemisia selengensis seedlings is above 15㎝, the harvest can be started. Harvest once every time, combined with watering and topdressing once to promote the growth of lateral branches. Use about available nitrogen fertilizer 10㎏ or about ammonium sulfate 15㎏ per mu, and apply thin fertilizer frequently. Pay attention to the moisture content of the border when watering, and it is advisable to be moist without water stains.

Five, pest control. 1, control measures of chrysanthemum diseases.

(1), Artemisia selengensis suddenly became ill. The damping-off disease is a disease of Artemisia selengensis caused by pythium infection, which has a great relationship with the soil planted. It mainly harms Artemisia selengensis seedlings, and pathogenic bacteria usually infect seedlings from the base of Artemisia selengensis. At the early stage of the disease, the diseased part of the seedling was flooded and then turned yellow-brown. Under the condition of high temperature and high humidity, white cotton-wool mildew appeared in the affected area, which led to the collapse of seedlings.

Agricultural control measures: the main control measures of the disease are ventilation and dehumidification, and increasing the illumination time of chrysanthemum. Greenhouse planting requires us to disinfect the soil with formalin in advance. If seedlings are sown, 50% carbendazim wettable powder should be mixed with nutrient soil according to the ratio of 1: 1.3 to form sterile soil, and the seedbed should be covered with medicinal soil to kill the hidden danger of seedbed germs.

Chemical control measures: 70% mancozeb 600 times solution, 75% chlorothalonil 600 times solution or 25% Daphne 900 times solution can be used when diseases are found. The effect of alternate medication is good, once every 6 days, 3 or 4 times in a row.

② Downy mildew of chrysanthemum: This disease belongs to fungal disease, and overwinters with spores or hyphae on diseased residues, shed facilities and seeds. In spring, this fungus will spread through wind and rain or field work, and it is easy to attack in rainy and foggy wet weather. This fungus mainly harms the leaf tissue of Artemisia selengensis. The disease usually starts from the outer leaves or lower leaves of plants and gradually spreads upwards. At first, the leaves of Artemisia selengensis were a little yellow, and there were no obvious circular spots on the edge. Slowly, these spots expand, the leaves fade and gradually dry up, and a white mold layer grows on the back of the leaves.

Agricultural control measures: Rotation with other crops and vegetables for more than 2 years is one of the effective methods to prevent this fungal disease. During sowing management, it is necessary to strengthen the air permeability in the field, water scientifically and reduce the humidity in the field. Pull out the diseased plants in time, disinfect the infected soil with quicklime, and take the diseased body out of the field for proper treatment.

Pesticide control measures: drug control should be carried out in time at the initial stage of the disease, and 500 times of 64% antiviral alum wettable powder, 600 times of 72% Plich aqueous solution or 700 times of 27% Kelv wettable powder can be selected for control. Take medicine once every 6 days or so, and take medicine for 2 ~ 3 times continuously.

③ Anthracnose of Artemisia selengensis: This pathogen mainly harms the leaves and stems of Artemisia selengensis. At first, yellow and white spots appeared on the infected parts of leaves, which gradually became round or quasi-round and turned brown. When the stem is infected, there will be depressions, longitudinal cracks, long strips or oval lesions. In high humidity environment, the focus usually secretes pink substances.

Agricultural prevention and control measures: rotate the diseased plots with non-compositae plants for more than 2 years, sow disease-free excellent seeds, use fully decomposed organic fertilizers, and apply more potassium fertilizer to increase plant stress resistance. Adjust the planting density in the field, improve the air permeability in the field, water frequently, strengthen the ventilation of the planting environment and reduce the humidity in the field.

Drug control measures: drug control should be taken immediately at the initial stage of the disease. You can choose 700 times solution of 50% Grifolan wettable powder, 700 times solution of 80% anthrax thiram wettable powder, 500 times solution of 40% duofengnong wettable powder, or 500 times solution of 50% tobrazin wettable powder. Take it once a week for 3-4 times continuously.

It can be clearly seen from these diseases of Artemisia selengensis that there are three main points in planting Artemisia selengensis to prevent diseases: one is to use sterile seeds, the other is to reduce soil-borne diseases through crop rotation, and the third is to manage the field properly, with good air permeability and low humidity. Grasping these three aspects well can reduce or even avoid the occurrence of chrysanthemum diseases in agricultural control.

2. Common diseases and insect pests of chrysanthemum.

1. Chrysanthemum Pieris rapae. This insect usually lays eggs on the back of the leaves of Artemisia selengensis. After the larvae hatch, they bite the leaves of Artemisia selengensis, leaving the epidermis. After the third instar, the damage is even greater, and eating Artemisia selengensis leaves can only leave veins.

Prevention and control measures: insect nets can be used for prevention. When the harm is serious, chemical agents can be used for prevention and control: 2.5% Kung Fu EC 1500 times solution, or 2.5% Fenjiu 2000 times solution, or spraying Bt reagent once every 8 days or so.

2. Artemisia selengensis aphid. Its nymphs or adults gather in groups on the back of the tender stems or leaves of Artemisia selengensis, sucking the juice of the plant. This insect has the ability to spread viral diseases and is extremely harmful to crops. Chrysanthemum is damaged by this insect, its leaves turn yellow and curly, and its plants grow poorly and are short.

Prevention and control measures: clearing weeds in the field, using silver-gray insect net or covering can play a role in avoiding aphids. Chemical control can be sprayed with 65438+2000 times 00% imidacloprid wettable powder or 4000 times 50% pirimicarb. Take the medicine once every 8 days or so, and take it 3 or 4 times in a row.

3. Artemisia selengensis Plutella xylostella. Plutella xylostella larvae will spin webs and gradually harden the leaf tissue. Adults will bite off mesophyll from the back of Artemisia selengensis leaves, leaving transparent spots on the epidermis, sometimes leaving only veins.

Agricultural control measures: if the whole process is covered with insect-proof nets to protect the planting, the use of chemicals can be reduced. You can also use frequency vibration to kill insects, light or black light to trap and kill adults. In the high incidence period of adults, you can also buy sex attractants used by adults and use them according to the instructions.

Chemical control: 50% Lu Bao wettable powder 1500 times solution or 5% Regent 3000 times solution can be used for control. Take the medicine about every 8 days.

For the pest control of Chrysanthemum morifolium, we growers should start with agricultural control, reasonable water and fertilizer, control the humidity and temperature of the space and intensive cultivation, so that the planted Chrysanthemum morifolium will not be prone to pests and diseases. During the harvest period, it is necessary to pay attention to stopping taking medicine 10 for more than 0 days to ensure the edible safety of Chrysanthemum morifolium during the harvest period. According to the habitat demand of chrysanthemum, intensive cultivation in the field, pest control according to the planting environment, and when to plant, good planting benefits can be obtained.