symptom
Mainly occurs at the base of the petiole or on the stem. Water-soaked, light brown spindle-shaped or irregular sunken spots appear first, and then become wet and rotten, turning black and smelly, and only the epidermis remains. This disease is easily confused with the symptoms of calcium deficiency in celery, so it is necessary to pay attention to the identification.
pathogen
Pectobacterium carotovora subsp.carotovora (Jones) Bergey et al., known as carrot pectin bacillus carrot pathogenic type, belongs to the genus Pectobacterium carotovora phylum Bacteria. For the morphological characteristics, physiology and biochemistry of the bacteria, see lettuce, lettuce soft rot bacteria.
Transmission routes and disease conditions
Pathogenic bacteria overwinter in the soil, invade from celery wounds, and spread through rainwater or irrigation water. The disease is severe in the late growth period under the conditions of high humidity. Sometimes mixed with frost damage or other diseases.
Prevention method
① Implement crop rotation for more than 2 years.
② Avoid root damage when planting, loosening the soil or weeding; the soil should not be too high, so as not to bury the petioles in the soil; drain water in time after the rain; dig out the diseased plants in time and sprinkle lime for disinfection; reduce watering or suspend watering during the onset period water.
③ Pay attention to the prevention and control of underground pests and reduce wounds.
④ Spray 72% agricultural high-efficiency streptomycin soluble powder 3000 times liquid or 90% neophytomycin soluble powder 4000 times liquid or 10% difenoconazole water dispersible granule 900 times liquid at the early stage of the disease, every 7 to 10 days 1 times, continuous prevention and treatment 2 to 3 times.
