Control Measures and Treatment Methods for Tulip Penicillium Rot
Tulips are world-famous bulbous flowers and also excellent cut flower varieties. The flowers are firm and upright, the leaves are elegantly simple and beautiful, and the lotus-like blooms are dignified and charming, making them much loved. However, in recent years tulips have frequently suffered from Penicillium rot, which seriously affects their growth and ornamental quality. Below, the editor discusses the symptoms of tulip Penicillium rot and its control measures.
I. Damage Symptoms of Tulip Penicillium Rot
Tulip Penicillium rot, also known as Penicillium bulb rot, mainly damages the bulbs, and the above-ground plants of infected bulbs often also show symptoms. In the early stage of infection, brown or dark brown sunken spots form on the bulbs, and the inner scales become water-soaked and gradually rot. When humidity is high, Penicillium and the pathogen's fruiting bodies grow both inside and outside, and a blue-green mold layer appears on the surface, finally causing the bulbs to become dry-rotted like decayed wood. Water-soaked lesions appear on the tips of young buds and tender leaves, with a clear boundary between diseased and healthy tissue. Plants growing from infected bulbs are stunted, with chlorotic, twisted and deformed leaves; flowers are deformed or fail to bloom, and finally the plants die prematurely. During storage, bulbs show no external symptoms in the early stage of disease; when cut crosswise and lengthwise, the mold layer can be seen spreading from the inner side of the scales toward the center, and the central growing point rots.
II. Control Methods for Tulip Penicillium Rot:
1. Improve soil structure and practice rational crop rotation. Tulips prefer fertile, well-drained soil. However, before planting, deep plowing should be carried out, artificial media should be added to improve soil structure, and sufficient base fertilizer should be applied. Continuous cropping of tulips easily leads to degeneration of variety characteristics and increases the accumulation of pests and diseases in the soil, raising the probability of pest and disease outbreaks; generally, rotation is needed once every 2-3 years.
2. Disinfect soil and seed bulbs. For soil disinfection, drench with a mixture of formalin (1:50) plus phoxim (1:1000), cover with plastic film for 7 days, then uncover and let it air-dry naturally (to avoid phytotoxicity to the bulbs), and plant after 14 days. For bulb disinfection, use carbendazim (1:800) plus propargite (1:1000), soak for 25-30 minutes, then dry in the shade, and plant the next day. If conditions permit, warm water soaking can also be used, but the temperature must be well controlled, generally around 52°C.
3. Strengthen management. Select disease-free bulbs with large diameter and high specific gravity. The planting depth should be 1-2 times the bulb diameter, and the row and plant spacing should be 15-20 cm x 15-20 cm to ensure ventilation and light penetration during the mature plant stage. Use a compound fertilizer of nitrogen, phosphorus and potassium, and apply a timely "weaning fertilizer" during the leaf-expansion stage. During the bud stage, to ensure flowering quality, potassium dihydrogen phosphate can be sprayed on the leaves 1-2 times along with fertilization. For bulb propagation, buds should be removed, then fertilizer applied to nourish the bulbs. When fertilizing, avoid fertilizer entering the flower center and causing heart rot. If the climate is dry, replenish water in time to promote root and shoot growth.
4. Chemical control during the growing period. After tulips emerge, close attention should be paid to stem and leaf diseases. Especially during the leaf-expansion stage, when plant vigor is relatively weak and the plants are highly susceptible to sclerotinia rot, late blight and other infections, a protective fungicide such as Daconi at 600 times dilution should be sprayed regularly, which gives very good protection. If diseased plants are found, thiophanate-methyl and carbendazim at 600-800 times dilution can be sprayed alternately. During the bud stage, noctuid moths occasionally feed on flower buds; they can be captured by hand, and spraying should be avoided, otherwise it will affect the flower buds. If mite pests occur, use propargite at 1500 times dilution for control.
5. Control during storage. Harvest bulbs before leaf withering, and try to keep bulbs without wounds for seed. Before storage, first fumigate and disinfect the storage room, then dry the disinfected bulbs in the shade before storing them. Generally, the storage temperature for tulips should be maintained at 22-25°C, with relative humidity of 70%-80%; afterward, the temperature should gradually drop to 18-20°C, and good ventilation should be maintained.
The above are the control methods for tulip Penicillium rot. Tulips often develop the disease in shaded and damp planting sites, where moisture stagnates and there are many underground pests; bulbs carrying the pathogen are severely affected during storage when humidity is high and ventilation is poor. Watering too much, excessive soil moisture in pots (when soil is squeezed by hand, water can be seen dripping down), and a temperature of around 20°C at the time are all very favorable for the reproduction of the Penicillium rot pathogen.
Control Methods for Tulip Penicillium Rot
Tulip Penicillium Rot:It belongs to the genus Penicillium of the Fungi Imperfecti, mainly damages bulbs, and is primarily saprophytic. The surface of affected bulbs is covered with a layer of green mold, and in severe cases the inner scales are also damaged. This disease mostly forms from infection through mechanical wounds or wounds caused by mite damage.
Control Methods:
1. Improve soil structure and practice rational crop rotation.Tulips prefer fertile, well-drained soil. However, before planting, deep plowing should be carried out, artificial media should be added to improve soil structure, and sufficient base fertilizer should be applied. Continuous cropping of tulips easily leads to degeneration of variety characteristics and increases the accumulation of pests and diseases in the soil, raising the probability of pest and disease outbreaks; generally, rotation is needed once every 2-3 years.
2. Disinfect soil and seed bulbs.For soil disinfection, drench with a mixture of formalin (1:50) plus phoxim (1:1000), cover with plastic film for 7 days, then uncover and let it air-dry naturally (to avoid phytotoxicity to the bulbs), and plant after 14 days. For bulb disinfection, use carbendazim (1:800) plus propargite (1:1000), soak for 25-30 minutes, then dry in the shade, and plant the next day. If conditions permit, warm water soaking can also be used, but the temperature must be well controlled, generally around 52°C.
3. Strengthen management.Select disease-free bulbs with large diameter and high specific gravity. The planting depth should be 1-2 times the bulb diameter, and the row and plant spacing should be 15-20 cm × 15-20 cm to ensure ventilation and light penetration during the mature plant stage. Use a compound fertilizer of nitrogen, phosphorus and potassium, and apply a timely "weaning fertilizer" during the leaf-expansion stage. During the bud stage, to ensure flowering quality, potassium dihydrogen phosphate can be sprayed on the leaves 1-2 times along with fertilization. For bulb propagation, buds should be removed, then fertilizer applied to nourish the bulbs. When fertilizing, avoid fertilizer entering the flower center and causing heart rot. If the climate is dry, replenish water in time to promote root and shoot growth.
4. Chemical control during the growing period.After tulips emerge, close attention should be paid to stem and leaf diseases. Especially during the leaf-expansion stage, when plant vigor is relatively weak and the plants are highly susceptible to sclerotinia rot, late blight and other infections, a protective fungicide such as Daconi at 600 times dilution should be sprayed regularly, which gives very good protection. If diseased plants are found, thiophanate-methyl and carbendazim at 600-800 times dilution can be sprayed alternately. During the bud stage, noctuid moths occasionally feed on flower buds; they can be captured by hand, and spraying should be avoided, otherwise it will affect the flower buds. If mite pests occur, use propargite at 1500 times dilution for control.
5. Control during storage.Harvest bulbs before leaf withering, and try to keep bulbs without wounds for seed. Before storage, first fumigate and disinfect the storage room, then dry the disinfected bulbs in the shade before storing them. Generally, the storage temperature for tulips should be maintained at 22-25°C, with relative humidity of 70%-80%; afterward, the temperature should gradually drop to 18-20°C, and good ventilation should be maintained.
Tulip Penicillium Rot
Tulip Penicillium rot, also known as tulip bulb rot. It mainly damages the bulbs, but can also show symptoms on the above-ground parts. Bruised bulbs are especially prone to this disease during storage. The surface of affected bulbs is covered with a layer of green mold, and in severe cases the inner scales are also damaged. Dark brown sunken lesions form on the bulbs, the inner scales gradually rot, and finally the bulbs become dry-rotted like decayed wood. The disease can also show symptoms on the above-ground parts during the growing period, namely water-soaked lesions on the tips of young leaves and tender leaves, with a clear boundary between diseased and healthy tissue, and the tips covered with Penicillium. Plants formed from infected bulbs are stunted, chlorotic, fail to bloom or produce deformed flowers, and die prematurely.
This disease is a fungal disease, and the pathogen is Penicillium corymbiferum of the genus Penicillium in the Fungi Imperfecti, primarily saprophytic. This disease mostly forms from infection through mechanical wounds, burns, or wounds caused by mite damage. Cool and shaded environments favor pathogen infection, and the disease develops rapidly when the storage site is poorly ventilated and stuffy. Bulbs are easily damaged during storage and transport, and bruised bulbs are the most susceptible.