Main diseases and insect pests of starry flowers and their control

Bemisia Tabaci

Symptoms: the young leaves of the plant faded to yellow, and finally the whole plant wilted and died.

Prevention and treatment:

(1) use "anti-insect net" to block the invasion of external insect pests.

(2) thoroughly fumigate the cultivation place and remove weeds before cultivation.

(3) 2.5% kung fu 2500-3000 times solution or 20% methamphetamine 2500 times solution was sprayed throughout the plant.

Grey mold disease

Symptoms: mostly caused by wet or overwatering in the rainy season. Waterlogged brown spots are produced at the edge of stems and leaves, which gradually expand to cause branches and leaves to rot. When the air humidity is high, gray mildew often appears in the disease department.

Prevention and treatment:

The main results are as follows: (1) keep the cultivation medium semi-dry, do not overwater, and strengthen the ventilation of the cultivation place.

(2) the cultivation medium was thoroughly disinfected.

(3) before cultivation, the site was disinfected with chlorothalonil smoke scavenging agent at a dose of 200 g / mu, which should be carried out continuously every 10 days.

(4) when the disease occurs, the whole plant is sprayed with 1500-fold solution of 50% prohydantoin or 2000-fold solution of Trichoderma.

Diseases of Starry Flower and its Control methods

Grey mold disease

Botrytis cinerea mostly occurs in the rainy season with high humidity, or is caused by overwatering.

In the early stage, the stems and leaves of the plant will produce waterlogged brown patches, but in the later stage, the plaques will gradually spread, resulting in withered leaves and branches and rotting. When the humidity in the air is relatively high, gray mildew will often appear in the affected parts.

Prevention and cure method

In the process of breeding starry flowers, the cultivation substrate should always be kept in a semi-dry state, do not overwater, and put the plants in a ventilated place.

Often change the matrix in the flowerpot, and disinfect the new pot soil with chlorothalonil, continue to disinfect the plant after cultivation, and use chlorothalonil every 10 days.

Once it is found that the plant is sick, it should be sprayed with 1500 times of hydantoin or 2000 times of Trichoderma. If the disease is more serious, it should be pulled out in time and burned.

Insect pests of star flowers and their control methods

Bemisia Tabaci

White whitefly, adults 1-1.5 mm long. The wings and chest and back are covered with white powder. After laying eggs at the top of the plant, the eggs will enter the leaf tissue and maintain water balance with the plant, which is not easy to fall off.

After hatching, the nymphs pierce the leaf tissue with mouthparts and absorb the nutrients in the plant, so that the leaves of the plant will fade and turn yellow, and eventually the whole plant will die.

Prevention and cure method

Insect prevention nets can be used to block the invasion of external pests at the initial stage of cultivation.

Before cultivation, flowerpots and soil should be sterilized to control the emergence of insect pests.

If families raise starry flowers and find adults of whitefly, they can use yellow plates to trap adults and apply stickworm glue to kill adults, but can not kill eggs, so pests are more likely to recur.

Once it is found that the plant has been harmed by whitefly, the whole plant should be sprayed with 2.5% kung fu 2500-3000 times liquid or 20% methamphetamine 2500 times solution, and the seriously damaged plants should be pulled out in time.

Cultivation methods of potted starry flowers and key points of disease and insect pest control

Recently, there are some flower friends in Huinong net backstage consultation: how to raise star flowers? Today we will briefly introduce how to cultivate and manage the beautiful potted starry flowers. Friends who are interested can also come and have a look.

1 feature characteristic

1.1 morphological characteristics

Artemisia angustifolia is an erect subshrub with 25~30cm plant height, thick green leaves and narrow leaf base with short stalks. Cymes, growing at the top of branches, each consisting of about 20 florets.

1.2 growth habits

Star flowers like warm, moist and well-lit environment, heat-resistant and drought-resistant. Avoid the scorching sun, slightly withstand the semi-overcast.

2 reproduction

Star flowers are mainly sown and propagated, and cutting propagation can also be used.

2.1 sowing

2.1.1 substrate sowing

The matrix can be made of peat soil or sowing special substrate; 50% carbendazim wettable powder is mixed with 50% carbendazim wettable powder according to 0.10% of the substrate weight to be sterilized. In the process of mixing carbendazim, water should be mixed while watering, so that the water content of the matrix should be pinched and not dripping; it can be used after drying for 24 hours.

2.1.2 Seedling container

The seedlings were raised by acupoint plate and 105 acupoint plate was used. The seeding box is used to raise seedlings, the best specification is 80cm × 50cm × 10cm, the box is too large, it is not convenient to carry, and if it is too small, the utilization rate is low.

2.1.3 sowing time

According to the time spent and pot specifications to determine the sowing time, 10cm potted plants need to be cultured for 18 weeks and 20 weeks before they can be put on the market for 15cm potted plants, and need to be cultivated for 20 weeks and 22 weeks.

2.1.4 sowing method

The seedlings were raised by ①. Fill the sterilized matrix into the seedling pot, then scrape it flat, press a shallow pit in the center of each hole, sow 2 seeds per hole because of the low emergence rate (about 60%), pay attention to the good light of the seeds and not cover the soil, and finally pour water through the sprayer to ensure that the seeds are in full contact with the substrate.

Seedlings were raised in ② seeding box. The sowing density is 2 000 to 4 000 seeds / m2, and the seeds can be evenly divided into several parts according to the area of the sowing box, 1 part per box. When sowing, the bottom of the sowing box is filled with perlite with 4cm thickness and poured with water to retain water and air. Then fill and sterilize the substrate close to the top of the sowing box, scrape the substrate and suppress it moderately, and then evenly mix the seeds with 3-10 portions of fine sand and spread them evenly on the surface of the substrate. do not cover the soil, pay attention to the four sides of the sowing box do not sow, because the substrate in the box will shrink in the process of raising seedlings, cracks appear around, which is not conducive to seed germination and seedling growth; finally, the seeds are watered thoroughly with a sprayer to ensure that the seeds are in full contact with the substrate. Because the seed is small and sprouting, it is not covered after sowing. Therefore, high seedling bed and air humidity should be maintained to ensure smooth germination. The optimum temperature for germination is 23-25 ℃. It germinated about 2-3 weeks after sowing, and the light substrate could be slightly covered with fine sieve after germination. The sowing medium requires that the pH is 6.50, 6.80, and EC is 0.75.The sowing medium requires that the sowing medium is 6.50, 6.80, and EC is 0.75.

③ post-broadcast management. Place the seeded hole tray or sowing box in an environment of about 28 ℃ during the day and 20 ℃ at night, spray water every day to keep the substrate fully moist, and the air relative humidity is more than 80%. Nitrogen fertilizer was applied once a week with a concentration of 50 × 10-6 (equivalent to 0.10% urea aqueous solution), 45% compound fertilizer was applied twice, and the concentration was 0.05%-0.08%. The matrix EC should be controlled at 1: 1.50 at seedling stage. Suitable for light, 1 000lux in germination stage, 10 000 ~ 30 000lux after germination, 50 000lux after germination.

④ seedling management. Star flowers begin to emerge about 15 days after sowing. When 80% of the seeds are germinated and unearthed, the ambient temperature should be lowered or transferred to a lower temperature greenhouse for cultivation, keeping the highest temperature in the day at 26 ℃ and the lowest temperature at night at 15 ℃, gradually strengthening the light and ventilation, and keeping the substrate moist, but to prevent excessive wetness and prevent the seedlings from overgrowing; the sun shading net should be covered when the temperature is above 26 ℃ and the sun is bright on a sunny day. After 2 pairs of true leaves are grown, 0.10% Huaduoduo 20 / 10 / 10 / 20 can be sprayed once every 7 to 10 days, and protective fungicides should be applied once after the first fertilization to prevent sudden collapse. When the true leaves grow, the seedlings begin to grow rapidly, keep the substrate humidity at 50%-70%, and let the substrate dry slightly before watering. Try to water it in the morning and dry in the evening. After the above-mentioned fine management, strong seedlings with luxuriant roots, sturdy roots and no diseases and insect pests can be cultivated.

2.2 Cuttage can be cut by burrowing dish or sowing box.

2.2.1 Matrix

As long as the matrix can be kept breathable, peat and perlite can be mixed well at 3:1, and 50% carbendazim wettable powder is added according to 0.10% of the weight of the matrix for sterilization. In the process of mixing carbendazim, mix and water at the same time, so that the water content of the matrix is appropriate to pinch without dripping, and it can be used after 24 hours; then put into the hole plate, gently compaction and flatten, scrape off the excess matrix; or add the substrate close to the top of the sowing box, scrape the matrix flat and suppress moderately.

2.2.2 preparation of inserts

The cuttings with the highest content of endogenous auxin and the strongest ability of cell division were obtained by selecting the strong mother plant and cutting the tender branches of the same year on the mother plant. Cut the twigs into small segments around 7cm, remove the lower leaves and cut off the upper leaves, then soak them in clean water to keep them moist and ready for use.

2.2.3 insert matrix

Insert the cuttings into the hole tray or sowing box, 1 branch for each hole, and the branches inserted into the sowing box should not cover each other with leaves and do not affect photosynthesis. The cutting depth should be 2cm, not too deep, so as not to affect rooting, and gently compact the surface of the substrate with hands after insertion.

2.2.4 Post-cutting management

After cutting, put the hole plate or sowing box under the shade net with a shading rate of 70% and the temperature is about 25 ℃. According to the weather conditions, spray water to the surface of the matrix every 2 hours in sunny days, and spray less or not on cloudy or rainy days to keep the air humidity at about 80%. At the same time, there can be no stagnant water in the matrix. About 30 days after cutting, new roots grow, and the times of spraying are gradually reduced. After the root system reaches 3cm, it can be transplanted or put on the pot to enter the normal management. Rooting is slower when the temperature is low.

(3) Post-basin management

3.1 put on the basin

When the third pair of true leaves of the seeding seedling grows or the root system of the cutting seedling reaches 3cm, it can be transplanted into the pot. The pot substrate can be well mixed with peat and perlite at the ratio of 4:1, and the disinfection method can be used with the sowing medium.

3.2 Lighting Management

The starry flowers enjoy sufficient sunshine and sufficient light, and the closer the plant is, the stronger the plant is. Therefore, in the winter of weak light and short-day sunshine, attention should be paid to supplementary illumination. Proper supplement of light can shorten the cultivation time by 2-3 weeks, and the flower stem will grow too long if the light is not enough. Greenhouse cultivation, can not block the light in winter; 30% shade in spring, summer and autumn. It is also ideal to grow in semi-overcast environment.

3.3 temperature management

Warm and sunny enough contribute to the growth of starry flowers. During the growth period, the night temperature should be kept above 17: 18 ℃ and the daily temperature should be above 22: 24 ℃. The temperature below 10 ℃ will make the plant blossom irregularly and delay or hinder the blooming of flowers.

3.4 Water and fertilizer management

Star flowers are more resistant to drought, but not to water and moisture. During the growth period, excessive watering should be avoided, and stagnant water in the cultivation substrate should be avoided so as not to induce root rot. When watering, the water temperature should not be too low. Overwatering often yellowes the plants and slows the growth of flowers. The water-soluble fertilizer of Huaduo 20 / 10 / 20 can be used for fertilization. The concentration of fertilizer is 0.20% in the first month after potting, 0.30% after the second month, and applied every 7 to 10 days.

3.5 Plant shape management

In order to get the ideal plant shape, it is generally necessary to pick the heart in 3 to 4 pairs of true leaves, and leave 2 pairs of true leaves after picking the heart. Cut off the residual flowers immediately after flowering, strengthen the fertilizer and water, which can promote the germination of new branches and continue to blossom. When the leaves of the lower branches of the old plant are sparse, the ornamental ability of the plant decreases, and a heavy pruning should be made to promote the lower part of the plant to branch and form a better plant shape.

(4) Disease and pest control

The common diseases and insect pests are quenching disease, gray mold, whitefly and so on.

4.1 cataplexy

Quenching disease is easy to occur in seedling stage, and the diseased seedlings suddenly lodge and die, which affects the survival rate of seedlings, and even destroys them all. The disease mainly occurred after the seedlings were unearthed and the base of the young stem was infected by bacteria. At first, the disease showed a small macular spot, and then turned pale brown to brown and constricted. The disease developed rapidly around the stem for 1 week, so that when the young leaves were still emerald green, they fell down and died from the base, so it was called sudden fall disease. In the end, the diseased seedlings rot or dry up. After sowing, it can also be infected from seed germination to unearthed, resulting in bud rot and seed rot, and the phenomenon of missing seedlings and broken ridges appears on the seedling bed. When the substrate humidity is high, a layer of white flocculent mycelium can be seen on the diseased seedlings and the nearby soil surface. The quenching disease is mainly caused by Pythium. The pathogen overwinters in the soil or on the remains of diseased plants, which is highly saprophytic and can survive in the soil for a long time, which is called soil habitual bacteria. Germs can be spread by irrigation water and Rain Water, as well as by bacteria-carrying compost, seeds and so on. High soil moisture in seedbed and sowing box, improper watering, over-dense sowing, uncomfortable temperature and thin seedling growth are all conducive to the occurrence of quenching disease. Continuous cropping seedbed or flower nursery has serious disease due to high accumulation of soil bacteria. Quenching disease is a typical soil-borne disease.

Prevention and control methods: ① improved seedling measures. Select high-lying, dry and well-drained areas as seedbeds; apply fully mature fertilizers or select high-quality culture soil; control the amount of irrigation at seedling stage, and the soil should not be too wet; sow in time so that the seedlings will not be affected by unsuitable temperature; sowing should not be too dense, and time seedlings, transfer seedlings, so that the nursery to maintain good ventilation; serious disease flower beds to avoid continuous cropping, or soil disinfection before sowing Carry out excellent seedling raising measures and cultivate strong seedlings to enhance disease resistance and reduce the harm of stunting disease. ② soil treatment. As the quenching pathogen can survive in the soil for a long time, it is of great significance to control the disease by directly eliminating the pathogen in the soil. 50% of carbendazim wettable powder can be mixed with 0.10% of the weight of the matrix for matrix sterilization. ③ chemical control. Spraying fungicides in the early stage of the disease can effectively control the epidemic of the disease. The commonly used fungicides are 50% carbendazim wettable powder 500 times solution, 25% metalaxyl (Ruidui) wettable powder 800 times solution, 40% aluminum ethyl phosphate (Phytophthora) wettable powder 200 times 400 times, 75% chlorothalonil wettable powder 600 times, etc., pay attention to spraying young stems and central diseased plants of seedlings and the diseased soil near them. The medicine was used once every 7 to 10 days, alternately, and sprayed continuously for 2 or 3 times, depending on the condition of the disease. In general, the prevention was carried out by spraying insecticides once at the seedling stage and at the initial stage of pot management.

4.2 Gray mold

Botrytis cinerea can harm leaves, stems, flowers and fruits. The symptoms were complicated, including leaf spot, canker, seedling quenching, organ decay, gray mold layer in wet environment, and the whole plant withered in severe cases. When the humidity is high, the disease is gray mildew, the disease is very easy to repeat, so the prevention and treatment of gray mold must persevere. In maintenance and management, ventilation should be enhanced, watering should be controlled on cloudy days, less nitrogen fertilizer should be applied, and diseased flowers and leaves should be removed in time; 50% Sukeling wettable powder 2000 times or 70% methyl topiramate wettable powder 1 000 times should be used every 7 to 10 days, alternately, spraying 2 times 3 times continuously, or depending on the disease.

4.3 White whitefly is small and white, and its flying ability is not strong. Adults and larvae absorb plant sap to make the damaged leaves withered and yellow, and the honeydew secreted by adults can lead to coal fouling disease. Control method: using yellow armyworm board to trap and kill, yellow armyworm board can be placed in the greenhouse, and flowers can be shaken artificially to kill the frightened white whitefly; it can be sprayed with 40% omethoate 1000 times, or 2.50% deltamethrin emulsion 2000 times, or 10% deltamethrin 2000 times once every 10 days, even 3 times 4 times, can get obvious effect.

The above are all the cultivation points of potted starry flowers. Welcome florist friends to download Huinong APP to learn at any time every day, and interested florists are also welcome to come to this site for reference!