The latest Technology and method course of Disease and Pest Control of Welsh Onion

Scallions are perennial herbs with cylindrical leaves, hollow in the middle, fragile and easy to fold, and cyan. In East Asian countries and Chinese regions, scallions are often eaten as a very common spice, condiment or vegetable, and play an important role in oriental cooking. The following editor will introduce the pest control techniques of scallions.

Brown spot of green onion

[disease characteristics] Welsh onion brown spot, also known as leaf tip verticillium wilt, mainly harms leaves, the leaf infection is easy to start from the upper, initially water-immersed yellow brown spots, and then generate fusiform disease spots, generally 10: 30 mm long, 3: 6 mm wide, the middle of the spot is grayish brown, the edge is brown, the spot is easy to produce black spots, that is, the apothecium, when serious, several major disease spots fuse, resulting in local dry leaves.

[agricultural control] ① selected high-foot white, three leaves Qi, chicken leg onions, Zhangqiu scallions and other heat-resistant varieties. ② strengthen management, timely drainage after rain, prevent onion fields from getting too wet, improve root activity and enhance disease resistance.

[chemical control] at the initial stage of the disease, 1000 times of 50% carbendazim wettable powder or 70% methyl thiophanate wettable powder were sprayed with 50% carbendazim wettable powder or 70% methyl thiophanate wettable powder. Add 75% chlorothalonil wettable powder 1000 times, once every 7 days, 2 times in a row.

Soft rot of green onion

[incidence characteristics] the bacterial soft rot of Welsh onion is on the rise year by year. Generally, the stem base extends from the bottom to the top, and the initial infection shows water-like long spots, and then produces translucent gray-white disease spots, then the base of the leaf sheath softens and decays, causing the leaves to collapse, the disease spots expand downward, and the pseudostem begins to rot at the beginning of the disease. after that, the interior began to rot, emitting the stench peculiar to bacterial diseases.

[agricultural control] ① increased the application of organic fertilizer to cultivate strong seedlings. Suitable period for planting, ploughing frequently, shallow watering, increasing the application of phosphorus and potassium fertilizer to prevent excessive nitrogen fertilizer. ② can control underground pests and aboveground pests in time and reduce man-made wounds.

[chemical prevention and cure] at the initial stage of the disease, 77% Ke'e wettable powder, 72% streptomycin sulfate soluble powder 2000 times, 10 million units of phytomycin 3000 times or 14% copper complex amine solution 250 times were selected at the initial stage of the disease, once every 7 to 10 days, even for 2 times.

Green onion yellow dwarf disease

[incidence characteristics] Welsh onion yellow dwarf disease, also known as Welsh onion virus disease, can get this disease from seedling stage to adult plant, the growth of diseased plants is blocked, the growth of diseased leaves is stagnant, the leaves are convex and uneven, wrinkled and twisted, the leaves become thinner, and the leaf tips are gradually yellowed. Sometimes yellowish-white stripes or yellow-green mottles of different lengths are produced on the leaves. The seriously diseased plants were seriously dwarfed, the leaves became smaller and flattened, the growth stopped, the wax decreased, the leaves sagged and yellowed, and in severe cases, the whole plant shrunk and died.

[agricultural control] before planting onions in ①, remove weeds in the field, remove diseased seedlings, fertilize and water timely and pay attention not to be adjacent to other onion crops. ② timely control aphids and thrips, choose 10% thalidomide 800 times, or 40% omethoate 1000 times or 50% methamidophos 1000 times mixture. ③ increased application of organic fertilizer, timely topdressing and spraying plant growth regulators to enhance disease resistance.

[chemical control] at the initial stage of the disease, 1.5% Zhiyanling emulsion was sprayed 800 times, or 20% virus A wettable powder 500 times, or 300 times emulsion plus 95,500 times Lufeng, once every 5-7 days, 2 times for 3 times.

Green onion anthracnose

[characteristics of the disease] damage leaves, flower stems and pseudostems. The initial infection of the leaves was nearly spindle-shaped, fusiform to irregular spots, grayish brown to brown, and there were many black spots on the spots, that is, the conidia disk, which caused the death of the upper leaves in severe cases. The pathogen is a fungus of the genus Trichoderma, which overwinters on the infected pseudostem in the soil with the conidium or conidium or mycelium, and is transmitted by Rain Water spatter.

[prevention and treatment methods] in rainy years, the disease is more serious in the low-lying land with poor drainage, which is usually sprayed at the initial stage of the disease with 80% anthrax Fumi wettable powder, or 1000 times of methyl topiramate or 70% Dasheng.