mosaic disease of common diseases of Canna plantain

Canna

Mosaic disease is the most common disease of canna. The incidence of canna cultured in East and South China is higher than that in the north, so what should be done once the canna is infected with the disease? The specific solution is as follows.

First, symptoms

In the early stage of the disease, the diseased canna leaves are chlorotic dots or flowers and leaves; in severe cases, the leaves are deformed, curled, yellowed, or even withered, and the plants are short; especially in common canna, large-flowered canna and pink-leaf canna, the symptoms are especially serious; safflower canna is more disease-resistant and brocade is formed on the petals. The canna planted in Beijing shows yellow-green or dark-green stripes, and the plant is short.

II. Pathogen

The pathogen of canna mosaic disease is cucumber mosaic virus (cucumber mosaic virus,CMV). The virus is icosahedral and 28m in diameter, the lethal temperature of juice is about 70 degrees Celsius, the dilution end point is 10-4, and the in vitro virus preservation period is below 20 degrees Celsius for 3-6 days. In addition, canna stunt virus (Canna dwarf viriod) was isolated from mosaic disease plants in China, which was preliminarily identified as the pathogen of etiolated symptoms.

III. Ways of transmission

The virus-carrying mother strain of canna is an important source of the virus, and ramet propagation is an important way of spread. Transmission in the field is through aphids. Aphids can carry the virus after feeding on the diseased plant for 1 minute and the virus on the healthy plant for 1 minute. The effective time of the virus in the worm is no more than 4 hours. The contact between diseased and healthy plants, field operation, can also transmit virus.

Fourth, the regularity of the disease.

Cucumber mosaic virus overwinters in diseased tubers and is transmitted by diseased tubers over a long distance. The occurrence of canna mosaic disease is very common. Due to the use of vegetative root-splitting propagation, the virus is passed on from generation to generation, which is aggravated year by year. Cucumber mosaic virus and beauty scorch mosaic virus are mainly transmitted by contact between aphids and juices, especially cotton aphids and corn aphids. It is easy to be inoculated with juice. if the friction inoculation method is used, it can produce virus disease symptoms on plants such as heart leaf tobacco, Sansheng tobacco, cucumber, quinoa, mandala, amaranth quinoa, thousand-day red, cowpea and broad bean. There are some differences in disease resistance among different varieties of canna. Common canna, big flower canna and pink leaf canna have serious disease, and safflower canna has strong disease resistance.

V. Prevention and control methods

1. Eliminate poisonous tubers, do not use poisonous roots as propagation materials, and discard the aboveground parts showing mosaic symptoms when digging tubers in autumn. As canna propagates in separate roots, it is easy to spread the virus year after year, so it is appropriate to choose a virus-free mother strain as the breeding material. Diseased plants were immediately removed and destroyed in order to reduce the source of infection.

two。 The disease is transmitted by aphids. Insecticides are used to control aphids and reduce disease vectors. Spray with 2000 times of 40% omethoate or 1000 times of 50% malathion, 20% flavored clothes and 70% aphid. Use carbaryl, marathon and other pesticides to control virus-borne aphids; CMV has many poisonous plants, which should be removed in time.

Common diseases of canna

Canna mosaic disease is a common disease of canna, which is common in the areas where canna is planted in China. Symptoms: flower leaves or yellow-green spots appear on the leaves of susceptible plants, petals become smaller and form a variety of colors, when the disease is more serious, the leaves become deformed, involute, plaque necrosis. Pathogen and pathogenesis: Canna mosaic disease is caused by cucumber mosaic virus (CMV). The main route of transmission is the contact between aphids and sap. There are some differences in disease resistance among different varieties of canna. Common canna, big flower canna and pink leaf canna have serious disease, and safflower canna has strong disease resistance. Control method: ① because canna is propagated in separate roots, it is easy to spread the virus year after year, so when propagating, it is appropriate to choose virus-free mother strain as propagation material. Diseased plants were immediately removed and destroyed in order to reduce the source of infection.' ② the disease is transmitted by aphids. Insecticides are used to control aphids and reduce disease vectors. Spray with 2000 times of 40% omethoate or 1000 times of 50% malathion, 20% diazinon and 70% aphid. Symptoms of canna bud rot: before canna unfolds and blossoms, bud rot bacteria invade through the stomata of young leaves and flower buds. During leaf expansion, many small disease spots appear on the leaves, and gradually expand, connecting with each other along the veins of the leaves to form large spots, sometimes the disease spots form stripes. The plaque is grayish white at first and soon turns black. The infected flower buds blacken and die before flowering. The disease spot can expand downward along the petiole, causing the death of young stems and buds. When the old leaf is damaged, the disease spot expands slowly, the shape is irregular, yellow, and the edge is watery. Pathogen: Xanthomonas [Xanthomonas sp.], belonging to Pseudomonas aeruginosa. The cell is solitary, rod-shaped, polar single flagellum, Gram staining negative, specific aerobic. This strain overwintered on the rhizome of canna, and the young plants in the greenhouse were killed earlier. Control methods: 1. Select healthy rhizome as propagation material, soak suspected bacteria-carrying rhizome in 500-1000 times solution of streptomycin for 30 minutes before planting, which can not only prevent disease, but also promote the growth of buds and branches. 2. It should be planted in sunny, fertile, moist and well-drained areas to avoid planting too dense. 3. Spraying Bordeaux solution (1purl 200) or 77% can kill 500-fold solution of wettable powder and 400-fold solution of 14% complexing ammonia copper solution in the early stage of plant disease. 4. Remove seriously diseased plants and remnants at any time and burn them.

Common diseases of canna and their solutions

Canna has bright colors and a long flowering period. it is one of the excellent flower varieties to beautify the environment. Some diseases will also occur in the conservation of canna. Let's learn about it below:

Canna disease:

Diseases of canna: 1. Black spot

Black spot is one of the common diseases of canna. In conventional cultivation, the disease is serious from June to August, with large withered spots and black fog on the back of the leaves, which occurs first from the leaf edge or leaf tip and then to the leaf center.

Solution: soak the bulb root with 50% methyl topiramate wettable powder 800 times for 5 minutes for 10 minutes before planting to prevent the disease. At the initial stage of the disease, the diseased leaves were cut off and burned, and 75% chlorothalonil wettable powder was sprayed once every 7 to 10 days for 2 to 3 consecutive times, which could inhibit the development of the disease.

Canna diseases: 2. Mosaic disease

Mosaic disease is a common disease of canna, when the disease occurs, there are mosaic or yellow-green spots on the leaves of the plant, petals become smaller and form a variety of colors, and when the disease is more serious, the leaves become deformed, involuted and plaque necrosis.

Solution: spray with 2000 times of 40% omethoate or 1000 times of 50% malathion, 20% diazinon and 70% aphid.

Diseases of canna: 3. Bud rot

Before the leaf development and flowering of the banana, the bud rot bacteria invaded through the stomata of the young leaves and flower buds. During the leaf development, many small disease spots appeared on the leaves, and gradually expanded, connecting with each other along the leaf veins to form large spots, and sometimes the disease spots formed stripes. The plaque is grayish white at first and soon turns black. The infected flower buds blacken and die before flowering. The disease spot can expand downward along the petiole, causing the death of young stems and buds. When the old leaf is damaged, the disease spot expands slowly, the shape is irregular, yellow, and the edge is watery.

Solution: soak in 500-1000 times solution of streptomycin for 30 minutes before planting, prevent and control bacteria, spray Bordeaux solution (1purl 200) or 77% can kill 500 times solution of wettable powder, 14% complex ammonia copper solution 400 times solution, etc., remove seriously diseased plants and remains in severe cases, and burn them.

Diseases of canna: 4. Leaf curling pests

Canna has strong adaptability, but it should pay attention to leaf curling pests from May to August every year, so as not to damage its young leaves and inflorescences.

Solution: it can be sprayed with 50% dichlorvos 800x solution or 50% prednisone EC 1000 times solution.

Canna has large flowers and bright colors, and breeding in the courtyard and other places will bring unexpected beautification results. In order to cultivate canna, it is necessary to pay attention to the occurrence and treatment of common diseases of canna. The solutions to common diseases of canna have been summarized to everyone. I hope it will be helpful to you.