Symptoms and Control Methods of Cyclamen Wilt Disease
Cyclamen wilt disease is a condition caused by Fusarium that makes the leaves wilt. In the early stages of infection, some of the plant's leaves turn yellow; on sunny days the leaves appear wilted, recover at night, wilt again during the day, and this continues until death. The petiole becomes swollen and water-soaked, and when air humidity is high, cotton-like white fungal colonies grow at the lesions
Cyclamen wilt disease is a condition caused by Fusarium that makes the leaves wilt. In the early stages of infection, some of the plant's leaves turn yellow; on sunny days the leaves appear wilted, recover at night, wilt again during the day, and this continues until death. The petiole becomes swollen and water-soaked, and when air humidity is high, cotton-like white fungal colonies grow at the lesions, sometimes tinged with pale red.
Conditions for onset: In greenhouses where cyclamen has been grown for many years, the soil carries the pathogen, and with watering it enters the roots through the drainage holes at the bottom of the pot and infects them. Plants that are weak in growth and have wounds on the roots are more likely to be infected. Under protected cultivation the disease occurs year-round, with July and August being the peak period.
Control measures: Once wilt disease has occurred, most chemicals have no obvious therapeutic effect, so production should focus on prevention, with comprehensive treatment.
1. Facility disinfection. After all cyclamen have been sold, thoroughly clean and sterilize the greenhouse; remove dead leaves, spent flowers, weeds and other waste, then disinfect. During the growing season, this can be done before the cyclamen flower buds extend out from the leaves: fumigate the greenhouse with chlorothalonil smoke agent 3 times, with an interval of four to five days between the first and third treatments, and 7 to 10 days between the second and third. For a solar greenhouse with an area of 1 mu, use three to four boxes each time. Light the smoke agent after 5 p.m., keep the greenhouse sealed for more than 4 hours, then ventilate.
2. Seed disinfection. When sowing, soak in 1000-fold potassium permanganate for 12 hours, rinse off the solution with clean water, then sow.
3. Substrate disinfection. For routine substrate disinfection, one week before potting, mix 500 g of carbendazim per cubic meter into the soil, or spray with 1000-fold potassium permanganate. You can also use metham-sodium mixed into the soil one month before potting, at 20 to 30 g per square meter. After disinfection, take care to protect the substrate from secondary contamination. Seven days before use, turn the disinfected substrate thoroughly to let it breathe and allow residual chemicals to volatilize.
I. Symptoms This disease is caused by Fusarium. In the early stages of infection, some of the plant's leaves turn yellow; on sunny days the leaves appear wilted, recover at night, wilt again during the day, until death. The petiole becomes swollen and water-soaked, sometimes with longitudinal cracks in the epidermis. When air humidity is high, cotton-like white fungal colonies grow at the lesions, sometimes tinged with pale red. Wilt disease is a soil-borne disease, and the affected parts turn brown and necrotic from the bottom upward. When the corm of a diseased plant is cut crosswise, the vascular bundles can be seen to have turned brown, but the corm generally does not rot.
II. Transmission route Wilt disease overwinters as mycelium or chlamydospores with diseased plant residues in the soil or attached to seeds. The pathogen generally invades through young roots or wounds, enters the vascular bundles, blocks the vessels, and produces toxic substances, causing the corm and leaves to turn yellow and die. Under high temperature and humid conditions the disease is more severe, and the pathogen spreads through water flow.
III. Conditions for onset In greenhouses where cyclamen has been grown for many years, the soil carries the pathogen, and with watering it enters the roots through the drainage holes at the bottom of the pot and infects them. Plants that are weak in growth and have wounds on the roots are more likely to be infected. Under protected cultivation the disease occurs year-round, with July and August being the peak period.
IV. Control measures Once wilt disease has occurred, most chemicals have no obvious therapeutic effect, so production should focus on prevention, with comprehensive treatment.
1. Facility disinfection After all cyclamen have been sold, thoroughly clean and sterilize the greenhouse; remove dead leaves, spent flowers, weeds and other waste, then disinfect. During the growing season, this can be done before the cyclamen flower buds extend out from the leaves: fumigate the greenhouse with chlorothalonil smoke agent 3 times, with an interval of four to five days between the first and third treatments, and 7 to 10 days between the second and third. For a solar greenhouse with an area of 1 mu, use three to four boxes each time. Light the smoke agent after 5 p.m., keep the greenhouse sealed for more than 4 hours, then ventilate.
2. Seed disinfection When sowing, soak in 1000-fold potassium permanganate for 12 hours, rinse off the solution with clean water, then sow.
3. Substrate disinfection For routine substrate disinfection, one week before potting, mix 500 g of carbendazim per cubic meter into the soil, or spray with 1000-fold potassium permanganate. You can also use metham-sodium mixed into the soil one month before potting, at 20 to 30 g per square meter. After disinfection, take care to protect the substrate from secondary contamination. Seven days before use, turn the disinfected substrate thoroughly to let it breathe and allow residual chemicals to volatilize.
4. Ground disinfection First scrape the ground thoroughly, then spray with 1000-fold potassium permanganate, or mix 3000 g of carbendazim per mu with an appropriate amount of clean river sand and spread it evenly over the ground. Use metham-sodium at 30 to 60 g per square meter, add an appropriate amount of clean river sand, spread it, then deep-till 20 cm and cover with plastic film. At a soil temperature of 10°C, fumigate for 27 days; at 15°C, fumigate for 20 days; at 20°C, fumigate for 16 days; at 25°C, fumigate for 13 days.
5. Pot disinfection Soak used pots in 1000-fold potassium permanganate for 2 hours; if possible, use new pots.
6. Off-ground pot cultivation If possible, set up raised dedicated flower benches or use pot stands so that the pots are kept off the ground.
7. Chemical control When diseased plants are found, either remove and destroy them, or use 500 g of 70% thiophanate-methyl plus 5 kg of clean river sand, mix evenly with uncontaminated sieved honeycomb briquette cinders, and dry-scatter onto the pot soil of diseased plants, once every 3 days, for 3 consecutive applications. Use 800- to 1000-fold 70% thiophanate-methyl solution, 800- to 1000-fold 80% carbendazim solution, 800-fold "Shadufan" solution, and 2000-fold benomyl solution alternately for root drenching, with 100 ml of solution per plant each time, once every 7 to 10 days.
Control Methods for Cyclamen Wilt Disease
I. SymptomsThis disease is caused by Fusarium. In the early stages of infection, some of the plant's leaves turn yellow; on sunny days the leaves appear wilted, recover at night, wilt again during the day, until death. The petiole becomes swollen and water-soaked, sometimes with longitudinal cracks in the epidermis. When air humidity is high, cotton-like white fungal colonies grow at the lesions, sometimes tinged with pale red. Wilt disease is a soil-borne disease, and the affected parts turn brown and necrotic from the bottom upward. When the corm of a diseased plant is cut crosswise, the vascular bundles can be seen to have turned brown, but the corm generally does not rot.
II. Transmission route
Wilt disease overwinters as mycelium or chlamydospores with diseased plant residues in the soil or attached to seeds. The pathogen generally invades through young roots or wounds, enters the vascular bundles, blocks the vessels, and produces toxic substances, causing the corm and leaves to turn yellow and die. Under high temperature and humid conditions the disease is more severe, and the pathogen spreads through water flow.
III. Conditions for onset
In greenhouses where cyclamen has been grown for many years, the soil carries the pathogen, and with watering it enters the roots through the drainage holes at the bottom of the pot and infects them. Plants that are weak in growth and have wounds on the roots are more likely to be infected. Under protected cultivation the disease occurs year-round, with July and August being the peak period.
IV. Control measures
Once wilt disease has occurred, most chemicals have no obvious therapeutic effect, so production should focus on prevention, with comprehensive treatment.
1. Facility disinfection: After all cyclamen have been sold, thoroughly clean and sterilize the greenhouse; remove dead leaves, spent flowers, weeds and other waste, then disinfect. During the growing season, this can be done before the cyclamen flower buds extend out from the leaves: fumigate the greenhouse with chlorothalonil smoke agent 3 times, with an interval of four to five days between the first and third treatments, and 7 to 10 days between the second and third. For a solar greenhouse with an area of 1 mu, use three to four boxes each time. Light the smoke agent after 5 p.m., keep the greenhouse sealed for more than 4 hours, then ventilate.
2. Seed disinfection: When sowing, soak in 1000-fold potassium permanganate for 12 hours, rinse off the solution with clean water, then sow.
3. Substrate disinfection: For routine substrate disinfection, one week before potting, mix 500 g of carbendazim per cubic meter into the soil, or spray with 1000-fold potassium permanganate. You can also use metham-sodium mixed into the soil one month before potting, at 20 to 30 g per square meter. After disinfection, take care to protect the substrate from secondary contamination. Seven days before use, turn the disinfected substrate thoroughly to let it breathe and allow residual chemicals to volatilize.
4. Ground disinfection: First scrape the ground thoroughly, then spray with 1000-fold potassium permanganate, or mix 3000 g of carbendazim per mu with an appropriate amount of clean river sand and spread it evenly over the ground. Use metham-sodium at 30 to 60 g per square meter, add an appropriate amount of clean river sand, spread it, then deep-till 20 cm and cover with plastic film. At a soil temperature of 10°C, fumigate for 27 days; at 15°C, fumigate for 20 days; at 20°C, fumigate for 16 days; at 25°C, fumigate for 13 days. 5. Pot disinfection Soak used pots in 1000-fold potassium permanganate for 2 hours; if possible, use new pots. 6. Off-ground pot cultivation If possible, set up raised dedicated flower benches or use pot stands so that the pots are kept off the ground. 7. Chemical control When diseased plants are found, either remove and destroy them, or use 500 g of 70% thiophanate-methyl plus 5 kg of clean river sand, mix evenly with uncontaminated sieved honeycomb briquette cinders, and dry-scatter onto the pot soil of diseased plants, once every 3 days, for 3 consecutive applications. Use 800- to 1000-fold 70% thiophanate-methyl solution, 800- to 1000-fold 80% carbendazim solution, 800-fold "Shadufan" solution, and 2000-fold benomyl solution alternately for root drenching, with 100 ml of solution per plant each time, once every 7 to 10 days.