What are the control methods for snake eye disease in Ceylon spinach?
Ceylon spinach (scientific name: Gynura cusimbua), also known as chan cai, luokui, tofu vegetable, purple angle leaf, is a plant of the genus Gynura, a perennial tall herb, 1.5-2 m tall. Flowering and fruiting period is September-October. Ceylon spinach is eaten as seedlings, tender shoots or tender leaves; its texture is tender and smooth, and its nutritional value is high. It can be used in soups, stir-fried, blanched, served cold, and so on. It has a delicate fragrance, and when chewed it is as crisp and refreshing as eating wood ear, hence the name Ceylon spinach. It is commonly cultivated in both the north and the south; in the tropical regions of the south it can be grown as a perennial, while in the north it is mostly grown as an annual.
The edible value of Ceylon spinach
The leaves contain a variety of vitamins as well as calcium and iron. It can be grown as a vegetable and also kept for ornamental purposes. The whole plant is used medicinally as a laxative and has the effects of lubricating the intestines, reducing heat, and promoting urination and defecation; the flower juice has the effect of clearing the blood and detoxifying, can neutralize smallpox toxin, and is applied externally to treat carbuncle toxin and cracked nipples. The fruit juice can be used as a harmless food colouring.
The ornamental value of Ceylon spinach
Ceylon spinach is a vine-type vegetable with many branches and tendrils, and people can use this characteristic to green courtyards and balconies. Its leaves are broad and thick, smooth and glossy. The small rice-grain-like flowers, red and white, are scattered among the leaf clusters like little stars, bright and eye-catching, very charming; the fleshy fruits, which turn from green to purple and then to black, hang in strings among them, full of interest. Whether in town or countryside, if you plant some on a balcony or in a courtyard, it can not only provide the whole family with food, but also beautify the living environment.
How to control snake eye disease in Ceylon spinach?
What is snake eye disease?
Snake eye disease occurs commonly and causes serious damage in Ceylon spinach whether grown under protection or in the open field, and it is an important disease of Ceylon spinach.
Symptom recognition of snake eye disease in Ceylon spinach
This disease mainly damages the leaves. At first the lesions are purplish brown, and later they develop into round or nearly round spots, with the central part greyish brown or yellowish brown and the edges purplish brown, somewhat sunken and film-like; because the tissue is thin, they finally tend to crack and perforate easily. On the lesions there are inconspicuous small black dots. In severe cases, the entire leaf is covered with lesions, losing its commercial value and becoming unfit for consumption. Key points for recognition: the edges of the lesions are purplish brown and the middle is greyish brown or yellowish brown, film-like, tending to crack later, with inconspicuous small black dots on the lesions.
The occurrence pattern of snake eye disease in Ceylon spinach
1. Pathogen Snake eye disease in Ceylon spinach is caused by infection by the fungus Cercospora sp., a member of the Deuteromycetes genus Phyllosticta. The conidiophores are light brown, thick and short, and the conidia are filamentous, colourless or pale.
2. Occurrence pattern The pathogen overwinters as mycelium or conidia on the soil surface with diseased plant residues (in the warm regions of the south, it causes damage year-round, so there is no overwintering issue). When environmental conditions are suitable the following year, the mycelium produces conidia or the conidia carry out primary infection. After disease onset, large numbers of conidia are produced on the diseased parts and spread by airflow, rain or irrigation water for secondary infection.
Control methods for snake eye disease in Ceylon spinach
1. Agricultural control
1) Practice crop rotation In diseased plots, rotate with cucurbits, solanaceous fruits, legumes, crucifers, Liliaceae and other vegetables for more than 2 years.
2) Rational close planting and scientific watering Planting density should not be too high. Watering should be done on sunny days and should not be excessive; avoid flooding irrigation. In the rainy season, drain promptly after rain. Under protection, strengthen ventilation after watering to reduce humidity; in the open field, loosen the soil promptly after rain.
3) Apply sufficient fertilizer Apply sufficient thoroughly decomposed manure and increase the application of phosphorus and potassium fertilizers to improve the disease resistance of the plants.
4) Clean the field Diseased leaves should be removed promptly. In addition, after harvest, diseased plant residues and fallen leaves should be thoroughly cleared away in good time and taken out of the field for deep burial or burning.
2. Biological control In the early stage of disease, spray 2% Wuyimycin (agricultural antibiotic BO-10) aqueous solution, or 2% antimycin (agricultural antibiotic 120) aqueous solution at 200 times dilution, once every 6 days, for 3-4 consecutive sprays.
3. Pollution-free pesticide control In the early stage of disease, spray 45% Tecto suspension concentrate at 800-1000 times dilution; for Ceylon spinach grown under protection, 3.3% Tecto smoke agent can be used, 250 g each time per 666.7 sq m, fumigated once every 7 days, for 3-4 consecutive times.