Harmful symptoms and control methods of plant Fusarium wilt

Fusarium wilt, also known as blight, is a plant disease caused by fungi or bacteria. symptoms include severe spots, wilting or death of leaves, flowers, fruits, stems or whole plants, and fast-growing young tissues are often invaded. Most important cash crops are infected by one or more blight diseases. Let's take a look at the prevention and control of Fusarium wilt.

Symptoms of Fusarium wilt

After the young plant was infected, the growth was poor, the leaves of the diseased seedlings became shallow, and there were no obvious symptoms. After being serious, the petiole folded down near the leaf sheath, dying and withered, and then the stem withered to death. Finally, the diseased root turned brown and rotted, the base of the stem was longitudinally split, and the vascular bundles were browned. The old leaves of the adult plants yellowed, accompanied by chlorosis of the vascular bundles of the outer leaf sheath. Yellowing starts from the leaf margin, and then gradually extends to the midrib, and some leaves are yellowed as a whole. The pink mildew layer is produced on the surface of the disease, that is, the pathogen conidiophores and conidia. Finally, the diseased root turned brown and rotted, the base of the stem was longitudinally split, and the vascular bundles were browned.

The incidence regularity of Fusarium wilt

The pathogen overwintered mainly as hyphae, chlamydospore or sclerotia in immature organic fertilizer or soil, and could survive in soil for 6 ~ 10 years. The pathogen could be transmitted by seed, fertilizer, soil and watering, mainly by composting and retting. The occurrence of the disease is closely related to temperature and humidity. The growth temperature of the pathogen is 5: 35 ℃ and the soil temperature is 24-30 ℃. The disease is a soil-borne disease, and the degree of the disease depends on the amount of infectious bacteria in the soil. Generally continuous cropping, there are many underground pests, extensive management, or soil sticky weight, moisture and other diseases occur seriously.

Preventive measures of Fusarium wilt

1. Irrigation prevention: 41% polypyrimidine was diluted in a solution of 600 to 800 times, and the seedling bed was irrigated before or after sowing and before planting at 10: 00 a.m. or after 5: 00 p.m.

2. Root irrigation prevention: 41% polypyrimidine was irrigated with 800 times dilution during or after planting and before the expected disease occurrence period, and the drug was used once every 7 days, depending on the disease.

Treatment of Fusarium wilt

1. Foliar spraying: 41% poly-pyrimidine 600 × 800 times diluted and evenly sprayed, when the disease is serious, the dosage can be increased appropriately.

2. Root irrigation treatment: the diseased plant was diluted 600 to 800 times to irrigate the root. If the pathogen is harmful to the aboveground part at the same time, the above-ground part should be sprayed at the same time, once every 7 days.

Harmful symptoms and control methods of plant brown spot (picture)

Brown spot is a fungal disease caused by Rhizoctonia solani, which is widely distributed all over the world, and can infect all turfgrasses, especially cold-season lawn grasses, causing lawn plant death, causing lawn to form a large area of bald spots, and greatly destroying the lawn landscape. let's take a look at what drugs are used to control brown spot.

Brown spot of lawn

[symptoms] when the disease begins on the lawn, near-round withered grass spots of different sizes often appear. When the conditions are suitable, the disease develops rapidly, and the diameter of subtilis spot can be extended from a few centimeters to one or two meters. As the diseased plant in the center of the disease spot can be recovered, as a result, the subtilis spot is mostly in the shape of "frog eye", that is, the center is green, and the edge is withered yellow band.

[prevention and control] it is necessary to apply little or no nitrogen fertilizer before or during the high temperature and humidity weather, maintain a certain amount of phosphorus and potassium fertilizer, avoid series irrigation and flood irrigation, especially in the evening. When there are withered spots on the lawn, spit (or dew) should be removed as early as possible in the morning to help alleviate the disease. Do not cut grass too low in summer (usually 5-6 cm), over-dense lawn should be properly punched, combed, withered grass and mowed residual grass should be removed in time, disease-resistant varieties should be planted, and timely and effective chemical control should be carried out.

Red and brown spot

[symptoms] the damaged leaves are small yellow-brown spots at first, and sometimes there are dozens of disease spots on one leaf. The small spot gradually enlarged into a disease spot with a diameter of 1 cm to 2 cm, with a light brown inside and a slightly angular and slightly different thickness of the concentric wheel spot. When the disease is serious, the diameter of the lesion can reach 2cm to 3cm. Grayish white woolly mildew occurred in the dark gray part of the transfer between the sick and healthy.

[prevention and treatment] thoroughly remove the diseased and residual bodies and reduce the source of primary infection. Do a good job in the management of temperature and humidity in the greenhouse, pay attention to ventilation and dehumidification, and improve ventilation and permeability.

Tulip brown spot

[symptoms] the infected leaf buds are malformed and curled, and the leaves that grow up after the tender buds are damaged become curly. If the environment is humid, a large number of gray mold conidia will be produced on the diseased tissue, which will affect the nearby healthy plants and make the leaves susceptible, so the growth of the bulb will be greatly affected. After the flowers are injured, white or light yellowish brown spots begin to appear, then expand rapidly and wither, or turn brown and dry. Banding also appears on the pedicel, and the conidium sometimes occurs above it.

[control] remove the diseased bulbs before planting, and carry out rotation planting. Once a bud or bud showing symptoms of the disease is found, it should be removed immediately to control the development of the disease. Before planting, soak the bulb in 2% formalin solution for 30 minutes, dry and plant, in order to reduce residual bacteria. During the growth period, 50% prohydantoin can be sprayed 1000 times or 50% promethrin 2000 times or 50% carbendazim 1000 times.

Sweet-scented osmanthus brown spot

[symptoms] occurred from April to October, and the disease was serious in rainy season and year, and the disease spread most rapidly from July to August. The disease of the old leaves is more serious than the tender leaves, and the plants with weak growth and transplanting in the same year are easy to suffer from the disease. Different varieties of sweet-scented osmanthus had different resistance to brown spot, and the disease resistance of osmanthus was stronger than that of Jingui and Yingui.

[prevention and treatment] when the seedlings came out of the nursery, remove the diseased leaves and spray 1000 times potassium permanganate solution for disinfection. The disease-free plant was selected as the breeding mother plant. Strengthen cultivation management, combined with crown shaping, cut off weak and diseased branches, adjust the density of branches and leaves, and enhance the tree potential. The whole tree is protected by spraying at the early stage of the growing season, such as 70% can kill 300 × 500 times, amiceta 1000 × 1500 times, or 50% carbendazim 500 times.

Brown spot of impatiens

[symptoms] Impatiens Brown spot, also known as Impatiens Leaf spot, occurs in the north and south of China. The disease mainly occurs in leaves. The foliar spot is a light yellowish brown spot at first, then expands into a circle or oval, and then the center becomes light brown, the edge is brown, with inconspicuous rims. On the seriously susceptible leaves, there are a series of disease spots, which causes the leaves to turn brown and yellow until the plant dies.

Impatiens prefers fertile sandy loam and is not resistant to waterlogging. Therefore, it is appropriate to plant sandy loam to facilitate drainage, potted impatiens, and should be poured out in time after rain. Diseased leaves and plants should be destroyed at the end of autumn to reduce the source of infection in the coming year. The initial stage of the disease with 25% carbendazim wettable powder 300 times 600 times liquid, or 50% methyl topiramate 1000 times solution, or 75% chlorothalonil 1000 times solution for prevention and treatment.

Morning glory brown spot

[symptoms] the disease spot on the leaf is scattered between the leaf veins and the leaf margin, nearly round to polygonal, 2mm in diameter, brown, or dark gray in the center, dark brown on the edge, light black mildew layer on the surface of the disease spot, in severe cases, the disease spot is covered with the whole leaf, and the leaf withered early.

[prevention and control] properly close planting, avoid excessive watering, spray 7500-fold solution of phytotin to promote early growth and rapid development of plants. Spray 75% chlorothalonil wettable powder 1000 times and 70% methyl thiobacillus wettable powder 1000 times, or more than 40%. Suspension emulsion 600 times liquid, 50% Sukeling wettable powder 2000 times liquid, once every 7-10 days, continuous prevention and treatment for 2 times.

Green chrysanthemum brown spot

[symptom] Chrysanthemum brown spot is a common leaf disease of green chrysanthemum. In severe cases, the leaves are withered and yellow, causing the whole plant to wither. At the initial stage, purple-brown spots of different sizes appear in the leaves, and then become black or dark brown. In the later stage, the center of the lesion turned light gray, reproducing small black spots. When there are more disease spots on the leaves, the whole leaves turn yellow and dry. It usually starts from the lower leaves and dies upward in sequence.

[prevention and control] choose areas with good drainage for planting. The planting density should be appropriate. Select disease-resistant varieties. Remove the diseased leaves immediately. At the end of autumn, the fallen leaves and disabled bodies were collected and destroyed. Spray 50% carbendazim wettable powder 1000 times solution, or 80% Dysen zinc wettable powder 500 times solution, or 1% Bordeaux solution, or 755 chlorothalonil 500 times solution. Spray once every 7 to 10 days.

Symptoms and Control methods of Carthamus tinctorius Wilt

Carthamus tinctorius is a kind of medicinal plant, which has high medicinal value, such as promoting blood circulation and relieving pain in medicine. The incidence site of safflower Fusarium wilt was vascular bundles. At the initial stage of the disease, the leaves of the plants turned yellow from bottom to top, and the tip withered, sometimes half yellow and atrophied. Next, the editor will introduce to you the symptoms and control methods of safflower wilt.

Symptoms of safflower wilt:

The lower leaves of the damaged plants were yellow at first, then gradually withered, and the whole old plant died. If one side of the plant is infected, this side dies. The seedlings suffered especially, and the roots of the affected seedlings were dark brown and thinned.

The pathogen of safflower wilt:

The pathogen is Fusarium oxysporum FsariumOxysporumSchlechtft.spCarthamiKlisetHoust, which belongs to Fusarium oxysporum.

Incidence regularity of safflower Fusarium wilt:

The pathogen spreads from the root to the stem, branch and leaf through the vascular bundle tissue, making the vascular bundle tissue of the root and stem turn yellowish brown. This fungus is parasitic on the soil and safflower remnants and is transmitted by the inner tissues of the seed shell and seed coat. It is easy to occur in acidic soil, high nitrogen content and warm and humid climate.

Prevention and control measures of safflower Fusarium wilt:

First, the use of rotation cultivation; second, no use of infected seeds; third, timely removal of diseased plants at the initial stage of the disease, concentrated burning, and sprinkling disease holes and surrounding soil with quicklime, and spraying 50% carbendazim wettable powder 600-800 times, or 10% Shuangxiaoling water 200-300 times.

These are the symptoms and prevention methods of safflower wilt sorted out by Xiaobian. The knowledge sorted out by Xiaobian is very helpful for you to grow your safflower. You can learn carefully to reduce the harm to your safflower.