What is celery leaf spot? Detailed control measures
Celery belongs to the Apiaceae family. There are three types: water celery, dry celery, and western celery. Their functions are similar, but dry celery is preferred for medicinal use. Dry celery has a stronger aroma and is called "medicinal celery". However, it is not the same species as cilantro. Celery is rich in protein, carbohydrates, carotene, B vitamins, calcium, phosphorus, iron, sodium, and more. At the same time, it has the effects of calming the liver and clearing heat, dispelling wind and removing dampness, relieving restlessness and reducing swelling, cooling blood and stopping bleeding, detoxifying and dispersing lung qi, strengthening the stomach and benefiting the blood, clearing the intestines and promoting bowel movements, moistening the lungs and stopping cough, lowering blood pressure, and calming the brain. Eating celery regularly, especially celery leaves, is very beneficial for preventing high blood pressure, arteriosclerosis, and more, and has auxiliary therapeutic effects.
Dry celery is rich in vitamin A, vitamin B1, vitamin B2, vitamin C, and vitamin P. It also contains high amounts of minerals such as calcium, iron, and phosphorus. In addition, it also contains components such as protein, mannitol, and dietary fiber.
The leaves and stems also contain medicinal components such as apiin, bergapten, and volatile oil, which have the effects of lowering blood pressure, lowering blood lipids, and preventing and treating atherosclerosis; they also have a certain auxiliary dietary therapeutic effect on neurasthenia, menstrual disorders, gout, and resisting muscle spasms; they can also promote gastric juice secretion and increase appetite. Especially for older people, because they have low physical activity, eat little, and drink insufficient water, they are prone to dry stool. Eating some celery regularly can stimulate gastrointestinal peristalsis and help with bowel movements.
Introduction and control measures of celery leaf spot
Chinese name of celery leaf spot: celery leaf spot. Chinese alias of celery leaf spot: early blight
Latin scientific name of celery leaf spot: Cercospora apii Fres.
Damage symptoms of celery leaf spot: it mainly occurs on leaves. The lesions are initially yellow-green and water-soaked, then develop into round or irregular shapes. When the disease is severe, the lesions join into patches and the leaves wither and die. When the air is humid, gray velvety mold grows densely on the lesions. The lesions on stems and petioles are oval, 3-7 mm in diameter, gray-brown, slightly sunken. When the disease is severe, the whole plant lodges, and in high humidity a gray mold layer grows on the surface of the diseased parts.
Morphological characteristics of the pathogen of celery leaf spot: conidiophores are produced in bundles, 2-11 per bundle, brown, unbranched; conidia are whip-shaped and transparent, straight or slightly curved, with a nearly truncated base, and have 3-19 transverse septa. The pathogen can infect mitsuba.
Taxonomic attributes of celery leaf spot: Cercospora celery fungus. Disease characteristics: the pathogen overwinters on seeds, diseased residues, or seed plants, becoming the primary infection source for the next year. Conidia spread and cause damage through rain, wind, airflow, irrigation water, and agricultural operations. The suitable temperature for pathogen development is 25-30 degrees Celsius, and the suitable temperature for conidia formation is 15-20 degrees Celsius. Although it may be high temperature and drought, heavy dew at night, long duration, or high temperature and high humidity in summer and autumn can easily cause disease. Lack of water, insufficient fertilizer, or excessive irrigation can lead to poor plant growth and severe disease.
Control measures for celery leaf spot:
1) Collect seeds from disease-free plants or disinfect seeds. Soak seeds in 48 degrees Celsius warm water at constant temperature for 30 minutes, then place them in cold water to soak for 5-10 minutes. Or sow seeds after storing them for 3 years.
2) When raising seedlings in high-temperature seasons, provide shade, prevent rainstorms, and cultivate strong seedlings.
3) Implement crop rotation for more than 2 years, plant at reasonable density, irrigate scientifically, and prevent excessively high field humidity.
4) Chemical control: spray pesticides in the early stage of disease onset. You can choose 50% carbendazim wettable powder 600 times solution, or 50% thiophanate-methyl wettable powder 600 times solution, or 70% mancozeb wettable powder 500 times solution, or 75% chlorothalonil wettable powder 600 times solution, or 1:1:200 Bordeaux mixture, or 12% copper green emulsifiable concentrate 400 times solution. Spray once about every 10 days, for 2-3 consecutive times.