Home › Nursery Stock › Article

Occurrence and Control of Carnation Damping-off

Nursery Stock 0 views
The pathogen of this disease is called Thanatephorus cucumeris, a fungus of the phylum Basidiomycota. Its asexual state is called Rhizoctonia solani, a fungus of the class Deuteromycetes. The pathogen mainly overwinters in the soil as sclerotia or mycelium along with diseased plant residues, and can live saprophytically in the soil for 2-3 years. After being spread by water flow and farm tools, the pathogen directly invades the host. Sowing too deep, relatively high temperatures, and excessively wet soil easily induce this disease, and it is also prone to occur under open-field cultivation. It is especially severe in continuous cropping fields during warm and rainy seasons. Symptoms are also called stem rot and basal rot. It begins at the stem base near the ground, producing dark brown oval or irregular water-soaked

The pathogen of this disease is called Thanatephorus cucumeris, a fungus of the phylum Basidiomycota. Its asexual state is called Rhizoctonia solani, a fungus of the class Deuteromycetes. The pathogen mainly overwinters in the soil as sclerotia or mycelium along with diseased plant residues, and can live saprophytically in the soil for 2-3 years. After being spread by water flow and farm tools, the pathogen directly invades the host. Sowing too deep, relatively high temperatures, and excessively wet soil easily induce this disease, and it is also prone to occur under open-field cultivation. It is especially severe in continuous cropping fields during warm and rainy seasons.

The symptoms are also called stem rot and basal rot. It begins at the stem base near the ground, producing dark brown oval or irregular water-soaked lesions, which later develop into slimy wet rot or soft rot, and the leaves gradually turn grayish-white. When the diseased area forms a ring-shaped rot, the entire plant suddenly wilts, causing mass death of cuttings. When humidity is high, thread-like mycelium or small brown sclerotia appear on the diseased area or on the soil surface at the root crown.

Control methods (1) Disinfection of seedbeds or seedling-raising pots. Spray 20% methyl tolclofos-methyl EC at 1200 times dilution or 95% Lyuheng No. 1 premium at 3000 times dilution onto 50-60 jin of sieved substrate, mix well after spraying, cover with plastic for 2-3 days, then fill the substrate back into the seedbed, and after watering, insert cuttings or sow. (2) The cutting depth should be 10 cm, and the cutting medium should have good permeability. After cutting, maintain suitable soil temperature and humidity, water lightly, and enhance soil permeability to promote rapid seedling growth and reduce disease occurrence. (3) Use rain-shelter cultivation. (4) After disease onset, immediately spray 20% methyl tolclofos-methyl EC at 1200 times dilution or 95% Lyuheng No. 1 premium at 3000 times dilution, or during the disease period apply 500 g of quintozene powder dissolved in 400 L of water and drench it into the soil. (5) Before cutting or transplanting, pour Trichoderma nutrient solution into the nursery soil to effectively suppress the occurrence of this disease.

Related Articles