Control methods of Sclerotinia sclerotiorum in celery with rot and white hair spreading

Sclerotinia sclerotiorum is an important disease in celery cultivation in protected field, which may occur from mid-late November to March of the following year.

Sclerotinia sclerotiorum

The main results are as follows: 1. Symptom identification: at the beginning of the disease, the upper leaves of celery, the base of the stem, or the leaves near the ground showed water-immersed rot, and the disease grew white flocculent filaments when the humidity was suitable. Through the contact between celery or branches and leaves, spread to the surrounding healthy plants. In the later stage, black mouse dung-like hard sclerotia were formed between the hyphae.

2. The law of disease: the pathogen overwintered and summer on the soil, seeds and celery plant residues with sclerotia. When the temperature and humidity were suitable, the sclerotia germinated to form an ascomycete disk, and the ascospores were formed in the ascomycete disc. Ascospores spread with airflow. The spores germinate on the host, produce silk to invade the celery tissue, then develop into hyphae, and then continue to infect the whole celery. Sclerotinia sclerotiorum is easy to occur in celery population with gloomy growth, low temperature, continuous rain and humidity.

3. prevention and control measures

(1) with disease-resistant varieties, the seeds need to be sterilized. Jinnan parsley, celery and other varieties can be used; select disease-free plants to leave seeds, then soak celery seeds in 50 ℃ warm water for 10 minutes for 20 minutes, or 1Rule 200 formalin for 3 minutes.

(2) strengthen cultivation management. Re-application of base fertilizer, combined with phosphorus and potassium fertilizer to prevent celery from growing and enhance disease resistance; reasonable close planting to enhance ventilation and light transmittance in the later stage; watering and greenhouse humidity were controlled according to the weather in the later stage.

(3) Pesticide control. In the early stage of the disease, the diseased celery plants were pulled out, put into plastic bags, taken out of the field for destruction, and prevented with drugs. 40% Sclerotinia net wettable powder 1000 / 1500 times liquid; or 50% prohydantoin wettable powder 1000 / 1500 times liquid; or 50% carbendazim wettable powder 500 times liquid spray. Once every 7 days for 2 times in a row. When spraying, first start from the healthy plant, and finally spray the diseased strain, so as to avoid the spread of bacteria by human operation. It can also be prevented by aerosol according to the humidity and weather conditions of the shed.