What is black rot of parsley?

What is black rot of parsley? How to prevent and cure it? Symptoms of black rot of coriander: it mainly harms the root stem and the base of petiole, mostly infects the disease near the ground, and sometimes infects the root. After infection, the injured part first turns grayish brown, then expands into dark green to dark brown, and the epidermis of the initial diseased part is intact. After rupture, the subcutaneous infected tissue turns black and rotten, especially the root crown is easy to rot, the leaves droop and wither, and the rotten parts rarely expand upward or downward. There are many small black spots in the disease department, that is, the conidium of the pathogen. Severe decay and exfoliation of outer leaves. Morphological characteristics of pathogen: phoma apiicola Kleb. It is called cilantro stem mildew, which belongs to the subphylum fungus. The young mycelium is colorless at first, grows black when it is ripe, and can produce small sclerotia on potato Agar medium. The conidium is spherical or hemispherical, black, exposed after burial, mostly formed in inconspicuous spots; the conidium has stomata, sporulation cells are single-celled, and the mode of sporulation is different from that of leaf spot mold. The conidia are colorless, long oval, 3.0 ~ 3.8 × 1.0 ~ 1.6 microns in size. The temperature limit for the growth and development of the pathogen and the germination of conidia was 5: 30 ℃ and 16: 18 ℃ was the most suitable. Prevention and treatment methods: (1) at the initial stage of the disease, 36% methyl thiophanate suspension 400 times or 10% Shuangxiaoling water agent 250 times per 667 square meters was sprayed 50 kg per square meter once every 10 days, even for 2 times. Click to get more coriander planting techniques click to get more vegetable planting techniques