How to prevent and cure carnation Fusarium wilt?

Fusarium wilt is caused by a bacterial infection. The top of the diseased plant or a few branches withered, the whole plant of a few diseased plants suddenly withered, the diseased branches dried and turned grayish green, and later became yellowish brown to dark brown. After the seedlings were infected, the leaves twisted to one side and the roots became soft rot and brown. Under the microscope, a large number of bacteria spilled from the diseased tissue (figure 27). The pathogen comes from rotten roots and branches. Therefore, the prevention and treatment of this disease should choose disease-free cuttings to propagate; do not damage the root when transplanting, the soil should not be too wet to avoid the harm of bacterial invasion.

Control measures of Fusarium Wilt of Carnation

1. Distribution and damage of Fusarium wilt is a common and serious disease of carnation, which occurs in Shanghai, Tianjin, Guangzhou, Hangzhou and other cities in China. The disease is harmful to a variety of carnation plants, such as carnation, carnation, American carnation and so on, causing plant wilt and death. two。 Symptomatic plants can be damaged at any period of growth and development. First of all, the lower leaves and branches of the plant changed color, wilted, and quickly spread upward, the leaves changed from normal dark green to light green, and finally showed pale straw color. The plant withered, sometimes one side or half of individual leaves were infected, the branches or leaves on one side obviously withered; the growth of twisted, deformed and stagnant shoots; the young plants died rapidly due to infection, and the diseased stem was cut longitudinally. Dark brown stripes can be seen in the vascular bundle, obvious dark brown ring can be seen from the cross section, the root quickly spread to the stem after infection, and the plant finally withered and died. 3. The pathogen of Fusarium wilt is FusaviumOxysporumf.spdianthiSnyetHans, which belongs to semi-known subphylum, Trichospora, Alternaria and Fusarium. It is the only pathogen causing vascular bundle disease of carnation. The pathogen generally produces conidia, and there are two types of conidia, namely large conidia and small conidia. Large conidia are stout, composed of several cells, slightly curved, sometimes sickle-shaped, apical slightly pointed, and thin spore wall; small conidia are smaller, ovate to rectangular round, with 1 color 2 cells, when the environment is unfavorable, dying plant tissue and soil residues can produce a large number of chlamydospores, which is a small, round thick-walled spore. According to the report of South China Agricultural University, the pathogen of carnation in Guangzhou is F.dianthpr-illetDel, which is named Fusarium oxysporum by Professor Wei Jingchao in China. Causing carnation wilt disease. The conidia are expansive, pale to purplish red, the large conidia are stout, sickle-shaped, one end is straight, the other end is slightly curved, 3murine 5 septum, colorless. Conidia with 3 septum, size 25-34.5 μ m × 3.8-4 μ m, 5 septum conidia with size 44 × 4.3 μ m; small conidia unicellular, colorless, oval or oval, size 5-9 μ m × 2-4 μ m; chlamydospore globose, 6-11 μ m in diameter, terminal or mesophytic; can produce sclerotia with diameter of 0.5-2.0mm or 3-12mm. According to Professor Yu Dayuan, there are also Fusarium oxysporum on carnation in China: Fusariumpoce (Peck) Wr., F.avenaceum (Fr.) Sacc.] And F.culmorum (W.G.Sm.) Sacc. They cause flower rot, root rot and stem rot of carnation respectively. At present, Fusarium oxysporum of Kentucky bluegrass is seriously harmful to carnation in Guilin, China. 4. The pathogen survived in the residual body or soil of the diseased plant, and the rot of the root or stem of the diseased plant produced fruiting body in the moist environment, and the spores were spread by airflow or the splash of Rain Water and irrigation water; the pathogen invaded through the wound at the base of the root and stem or cuttings, and the pathogen entered the vascular bundle system and gradually spread upward. The pathogen may colonize in the vascular bundle system without symptoms. The study on the expansion of bacteria in the host showed that the expansion of bacteria in the vascular bundle was not fast before the appearance of symptoms, but some of the culture materials obtained from susceptible mother plants may have hidden parasitism. Therefore, aquaculture material is an important source of disease transmission, and contaminated soil is also one of the sources of disease transmission. Generally in spring and summer, if the soil temperature is high, the rain is continuous, and the soil is stagnant, the disease will occur seriously. Excessive application of nitrogen fertilizer and acidic soil in cultivation are conducive to the growth and infection of bacteria and promote the occurrence and prevalence of diseases. Fusarium wilt often occurs from April to June in Guangzhou. 5. Prevention and control measures should take cuttings from healthy disease-free mother plants, and it is best to establish a disease-free mother area for collecting strips. Diseased plants were removed and destroyed in time to reduce the accumulation of bacteria in the soil. Soil treatment the soil or basin soil in the nursery is contaminated and must be replaced or disinfected before use. Conditional greenhouses can be disinfected with steam, and foreign countries have used sodium and bromomethane to fumigate the soil; irrigate the soil with 50% carbendan or 50% carbendazim 500 times before planting, or 70% dimethoprim 500 times solution, or 3% ferrous sulfate treatment soil has control effect. Biological control is a promising measure. In recent years, there have been many reports abroad, such as applying Metz high-quality sandy mud to the soil according to the amount of 600g/m2 before planting in the United States can control the occurrence of carnation Fusarium wilt. According to research, this fine sandy mud contains a kind of Pseudomonasputida (Trevisan) Migula, which has antagonistic effect against pathogens and competes with it for iron element, so as to achieve the purpose of disease prevention. Another method is to use a bacterium (Chitinolyticsp.) After treatment of soil, the effect of disease can be reduced. In addition, a kind of bottle mold (Phialophoracinerescens) also causes carnation Fusarium wilt. The fungus invades the plant through wounds, tiny root tips and root hairs, enters the ducts, and hinders water transport. And the toxins produced by the bacteria damage the living tissue of the host, causing the plant to wilt. The affected tissue turned brown and there was no clear boundary between the diseased and healthy tissues. Plants can be infected at different stages of development. For prevention and control measures, see Fusarium wilt of carnation. .

Symptoms and Control of Fusarium Wilt of Carnation

1. Distribution and harm Fusarium wilt is a common and serious disease of carnation, which occurs in Shanghai, Tianjin, Guangzhou, Hangzhou and other cities in China. The disease is harmful to a variety of carnation plants, such as carnation, carnation, American carnation and so on, causing plant wilt and death.

two。 Symptomatic plants can be damaged at any period of growth and development. First of all, the lower leaves and branches of the plant changed color, wilted, and quickly spread upward, the leaves changed from normal dark green to light green, and finally showed pale straw color. The plant withered, sometimes one side or half of individual leaves were infected, the branches or leaves on one side obviously withered; the growth of twisted, deformed and stagnant shoots; the young plants died rapidly due to infection, and the diseased stem was cut longitudinally. Dark brown stripes can be seen in the vascular bundle, obvious dark brown ring can be seen from the cross section, the root quickly spread to the stem after infection, and the plant finally withered and died.

3. The pathogen of Fusarium wilt is Fusavium Oxysporum f. Sp dianthi Sny et Hans, which belongs to semi-known subphylum, Trichospora, Alternaria and Fusarium. It is the only pathogen causing vascular bundle disease of carnation. The pathogen generally produces conidia, and there are two types of conidia, namely large conidia and small conidia. Large conidia are stout, composed of several cells, slightly curved, sometimes sickle-shaped, apical slightly pointed, and thin spore wall; small conidia are smaller, ovate to rectangular round, with 1 color 2 cells, when the environment is unfavorable, dying plant tissue and soil residues can produce a large number of chlamydospores, which is a small, round thick-walled spore. According to the report of South China Agricultural University, the pathogen of carnation in Guangzhou is F. dianth pr-ill et Del, which is named Fusarium oxysporum by Professor Wei Jingchao in China. Causing carnation wilt disease. The conidia are expansive, pale to purplish red, the large conidia are stout, sickle-shaped, one end is straight, the other end is slightly curved, 3murine 5 septum, colorless. Conidia with 3 septum, size 25-34.5 μ m × 3.8-4 μ m, 5 septum conidia with size 44 × 4.3 μ m; small conidia unicellular, colorless, oval or oval, size 5-9 μ m × 2-4 μ m; chlamydospore globose, 6-11 μ m in diameter, terminal or mesophytic; can produce sclerotia with diameter of 0.5-2.0mm or 3-12mm.

According to Professor Yu Dayuan, there are other Fusarium oxysporum on carnation in China: Fusarium poce (Peck) Wr., F.avenaceum (Fr.) Sacc. And F.culmorum (W.G.Sm.) ) Sacc and other 3 species. They cause flower rot, root rot and stem rot of carnation respectively. At present, Fusarium oxysporum of Kentucky bluegrass is seriously harmful to carnation in Guilin, China.

4. The pathogen survived in the residual body or soil of the diseased plant, and the rot of the root or stem of the diseased plant produced fruiting body in the moist environment, and the spores were spread by airflow or the splash of Rain Water and irrigation water; the pathogen invaded through the wound at the base of the root and stem or cuttings, and the pathogen entered the vascular bundle system and gradually spread upward. The pathogen may colonize in the vascular bundle system without symptoms. The study on the expansion of bacteria in the host showed that the expansion of bacteria in the vascular bundle was not fast before the onset of symptoms, but some of the reproductive materials obtained from susceptible mother plants may have hidden parasitism. Therefore, the reproductive material is an important source of disease transmission, and the contaminated soil is also one of the sources of transmission. Generally in spring and summer, if the soil temperature is high, the rain is continuous, and the soil is stagnant, the disease will occur seriously. Excessive application of nitrogen fertilizer and acidic soil in cultivation are conducive to the growth and infection of bacteria and promote the occurrence and prevalence of diseases. Fusarium wilt often occurs from April to June in Guangzhou.

5. Prevention and control measures should take cuttings from healthy disease-free mother plants, and it is best to establish a disease-free mother area for collecting strips.

Diseased plants were removed and destroyed in time to reduce the accumulation of bacteria in the soil.

Soil treatment the soil or basin soil in the nursery is contaminated and must be replaced or disinfected before use. Conditional greenhouses can be disinfected with steam, and foreign countries have fumigated the soil with sodium and bromomethane; irrigated the soil with 50% carbendan or 50% carbendazim 500 times before planting, or 70% dimethazone 500 times solution, or 3% ferrous sulfate treatment soil has control effect.

Biological control is a promising measure. In recent years, there have been many reports abroad, such as applying Metz high-quality sandy mud to the soil according to the amount of 600g/m2 before planting in the United States can control the occurrence of carnation Fusarium wilt. According to research, this fine sandy mud contains a kind of Pseudomonas putida (Trevisan) Migula, which has antagonistic effect against pathogens and competes with it for iron element, so as to achieve the purpose of disease prevention. Another method is to use a bacteria (Chitinolytic sp. The treatment of soil can reduce the effect of disease.

In addition, a kind of bottle mold (Phialophora cinerescens) also causes carnation Fusarium wilt. The fungus invades the plant through wounds, tiny root tips and root hairs, enters the ducts, and hinders water transport. And the toxins produced by the bacteria damage the living tissue of the host, causing the plant to wilt. The affected tissue turned brown and there was no clear boundary between the diseased and healthy tissues. Plants can be infected at different stages of development. For prevention and control measures, see Fusarium wilt of carnation.