What if the canna is infected with bacterial wilt?

Canna

In order to beautify the living environment and improve people's aesthetics, canna has been planted on both sides of the road in recent years. It is very popular with people because of its rich color and fragrance, but it is prone to the devastating bacterial wilt of canna in some areas, which seriously affects the landscape value, so what is the cause of bacterial wilt of canna? What should I do if there is such a problem?

First, symptoms

The pathogen infected the stem and root of the plant, and the plant generally lasted 10-15 days from infection to death during the epidemic period. Most of them were infected from the root, but also invaded from the stem, the upper leaves of the diseased plant lost water and turned yellow, wilted and drooped, gradually appeared black stripes on the stem base or stem, and the whole plant withered after a week around the stem (figure 1). Cross-cut necrotic roots or stems, a few minutes later, milky white or yellowish-brown bacterial mucus overflow on the section, this is the pathogenic bacteria, is an important basis for outdoor diagnosis of bacterial wilt. Strips of dark brown spots can also be seen if the stem is cut longitudinally.

II. Pathogen

Canna bacterial wilt (Pseudomonassolanacearum) is caused by Pseudomonas solanacearum and Pseudomonas solanacearum. The bacteria were short rod-shaped, obtusely round at both ends, with 1-4 flagella at the extreme (Fig. 2), and Glenn's staining was negative. The size is 1.5 ~ 2.3 × 0.5 ~ 0.7 microns. The optimum temperature for growth and development of the pathogen was 34 ℃, the highest was 37 ℃ and the lowest was 18 ℃. For acid-base adaptation range pH6~8, the most suitable pH6.6.

Third, occurrence regularity

The pathogen can survive in a mixture of soil, plant residues and garbage, such as peanuts, tomatoes, eggplants, tobacco, Casuarina equisetifolia, eucalyptus, chrysanthemum, dahlias, and the soil fertilizer and water sources that come into contact with the diseased bodies of flowers, stems, roots and leaves of these diseased plants. Bacterial wilt may occur if these soils, water and fertilizers are used to cultivate canna. The pathogen can survive in soil for more than 1 year, but only 30 days and 90 days when dry or flooded. Bacteria mainly invade from the host wound, wind and rain damage, insect eating, human activities will create opportunities for the invasion of bacteria. Surface runoff and root connection between plants are the main transmission routes in the intercompartment. Long-distance transmission depends on the propagation of diseased tubers. Generally, the disease begins in March every year, the disease is serious from June to October, and the peak is from July to September. After typhoon rain, when the atmospheric temperature is 33-35 ℃ and the relative humidity is more than 80%, bacterial wilt is most likely to be prevalent if there is stagnant water in green space.

IV. Prevention and control measures

1. Do not take tubers in disease areas as breeding materials, strict quarantine, found that a batch of diseased seedlings, should be eliminated in batches.

two。 Do not plant canna on soil where bacterial wilt has occurred. If you want to apply soil fertilizer, you should first compost, fully mature, or spray 6 kilograms of 40% formalin 50 times solution per square meter and cover the film for disinfection.

3. Don't cut weeds by ploughing and weeding during the epidemic period to avoid damaging plants. The diseased plant was immediately removed, dug up the diseased soil and sprinkled around with 25% Qingkuling 400 × 600 liquid or 90% soil, 3000 × 4000 solution of streptomycin or sulfur powder. It is best to sprinkle the above agents once after the typhoon in the ward.

Bacterial wilt of canna

The symptomatic pathogen infected the stem and root of the plant, and the plant generally lasted 10-15 days from infection to death during the epidemic period. Most of them were infected from the root, but also invaded from the stem, the upper leaves of the diseased plant lost water and turned yellow, wilted and drooped, gradually appeared black stripes on the stem base or stem, and the whole plant withered after a week around the stem (figure 1). Cross-cut necrotic roots or stems, a few minutes later, milky white or yellowish-brown bacterial mucus overflow on the section, this is the pathogenic bacteria, is an important basis for outdoor diagnosis of bacterial wilt. Strips of dark brown spots can also be seen if the stem is cut longitudinally. The pathogen Canna bacterial wilt (Pseudomonassolanacearum) is caused by Pseudomonas solanacearum and Pseudomonas solanacearum. The bacteria were short rod-shaped, obtusely round at both ends, with 1-4 flagella at the extreme (Fig. 2), and Glenn's staining was negative. The size is 1.5 ~ 2.3 × 0.5 ~ 0.7 microns. The optimum temperature for growth and development of the pathogen was 34 ℃, the highest was 37 ℃ and the lowest was 18 ℃. For acid-base adaptation range pH6~8, the most suitable pH6.6. Occurrence regularity: the pathogen can survive in a mixture of soil, plant residues and garbage, and bacterial wilt bacteria may exist and reproduce in soils where infected plants such as peanuts, tomatoes, eggplants, tobacco, Casuarina equisetifolia, eucalyptus, chrysanthemum and dahlias have been planted, as well as the soil fertilizer and water that have come into contact with the diseased bodies of flowers, stems, roots and leaves of these diseased plants. If these soil, water and fertilizer are used to cultivate canna, bacterial wilt will occur. The pathogen can survive in soil for more than 1 year, but only 30 days and 90 days when dry or flooded. Bacteria mainly invade from the host wound, wind and rain damage, insect eating, human activities will create opportunities for the invasion of bacteria. Surface runoff and root connection between plants are the main transmission routes in the intercompartment. Long-distance transmission depends on the propagation of diseased tubers. Generally, the disease begins in March every year, the disease is serious from June to October, and the peak is from July to September. After typhoon rain, when the atmospheric temperature is 33-35 ℃ and the relative humidity is more than 80%, bacterial wilt is most likely to be prevalent if there is stagnant water in green space. Prevention and control methods: 1. Do not take tubers in disease areas as breeding materials, strict quarantine, found that a batch of diseased seedlings should be eliminated in batches. 2. Don't plant canna on the soil where bacterial wilt has occurred. If you want to apply soil fertilizer, you should first compost, fully mature, or spray 6 kilograms of 40% formalin 50 times solution per square meter and cover the film for disinfection. 3. During the epidemic period of the disease, do not ploughing and weeding to avoid damage to plants. The diseased plant was immediately removed, dug up the diseased soil and sprinkled around with 25% Qingkuling 400 × 600 liquid or 90% soil, 3000 × 4000 solution of streptomycin or sulfur powder. It is best to sprinkle the above agents once after the typhoon in the ward.

Control methods of bacterial wilt of canna

In recent years, the hybrid canna planted in gardens and roadsides is deeply loved by people because of its short and sturdy plant type, dark green leaves, rich flowers and bright colors. However, in 1998, a large area of green space in Shenzhen suffered a devastating bacterial wilt. Nearly 100000 plants are lost every year, and the incidence rate of the disease area is 2030%. Serious death affects the landscape.

The pathogen infected the stem and root of the plant, and the plant generally lasted 10-15 days from infection to death during the epidemic period. Most of them were infected from the root, but also invaded from the stem, the upper leaves of the diseased plant lost water and turned yellow, wilted and drooped, and gradually black stripes appeared on the stem base or stem, and the whole plant withered after a week around the stem. Cross-cut necrotic roots or stems, a few minutes later, milky white or yellowish-brown bacterial mucus overflow on the section, this is the pathogenic bacteria, is an important basis for outdoor diagnosis of bacterial wilt. Strips of dark brown spots can also be seen if the stem is cut longitudinally.

Occurrence regularity: the pathogen can survive in a mixture of soil, plant remains and garbage. Any soil that has grown infected plants such as peanuts, tomatoes, eggplants, tobacco, Casuarina equisetifolia, eucalyptus, chrysanthemum, dahlias, and the soil fertilizer and water sources that come into contact with the diseased bodies of flowers, stems, roots and leaves of these diseased plants may exist and reproduce bacterial wilt bacteria. If these soils, water and fertilizer are used to cultivate canna, bacterial wilt will occur. The pathogen can survive in soil for more than 1 year, but only 30 days and 90 days when dry or flooded. Bacteria mainly invade from the host wound, wind and rain damage, insect eating, human activities will create opportunities for the invasion of bacteria. Surface runoff and root connection between plants are the main transmission routes in the intercompartment. Long-distance transmission depends on the propagation of diseased tubers. Generally, the disease begins in March every year, the disease is serious from June to October, and the peak is from July to September. After typhoon rain, when the atmospheric temperature is 33-35 ℃ and the relative humidity is more than 80%, bacterial wilt is most likely to be prevalent if there is stagnant water in green space.

Prevention and control methods:

1. Do not take tubers in disease areas as breeding materials, strict quarantine, found that a batch of diseased seedlings, should be eliminated in batches.

two。 Do not plant canna on soil where bacterial wilt has occurred. If you want to apply soil fertilizer, you should first compost, fully mature, or spray 6 kilograms of 40% formalin 50 times solution per square meter and cover the film for disinfection.

3. Don't cut weeds by ploughing and weeding during the epidemic period to avoid damaging plants. The diseased plant was immediately removed, dug up the diseased soil and sprinkled around with 25% Qingkuling 400 × 600 liquid or 90% soil, 3000 × 4000 solution of streptomycin or sulfur powder. It is best to sprinkle the above agents once after the typhoon in the ward.