Introduction and control measures of fennel powdery mildew

Fennel and cumin are commonly used seasonings, which are necessary for roasting fish stew and making stewed food. Because they can remove the stench from the meat and make it fragrant again, it is called "fennel". Fennel is a big material, the scientific name is "star anise". The seed of cumin is a condiment, and its stems and leaves also have fragrance, which is often used as stuffing for food such as steamed buns and dumplings. The main ingredients they contain are fennel oil, which can stimulate gastrointestinal nerves and blood vessels, promote digestive juice secretion, increase gastrointestinal peristalsis, and eliminate accumulated gas, so they have the effect of invigorating the stomach and promoting qi; sometimes gastrointestinal peristalsis decreases after excitement, thus helping to relieve spasm and pain. Alias fennel seed, fennel, fennel, Huaixiang, coriander, cumin.

Nutrition and efficacy of fennel

Fennel is rich in vitamins B1, B2, C, PP, carotene and cellulose. What causes it to have a special pungent smell is fennel oil, which can stimulate the nerves and blood vessels of the intestines and stomach and has the effect of invigorating stomach and regulating qi, so it is an excellent vegetable with meat and oil. Fennel vegetable cooked food or soak wine drinking service, can be gas, cold, pain relief. Fennel seedling leaves ramming juice drink or external application, can treat vicious carbuncle swelling.

Types of fennel

Fennel is also known as fennel seedling. It is a 1 ~ 2-year herb of Umbelliferae. The whole plant has a special fragrance, mainly for stuffing, but also can be fried. There are different types of fennel, such as cumin, fennel and bulb fennel.

1) cumin: the plant is relatively short, with a height of 20cm and 35cm, with 7-9 leaves, short petiole, small leaf spacing, slow growth and late bolting. There is a difference between round seed and flat seed of cumin. The round seed has shorter growth period, earlier bolting and lower yield, while the flat seed has strong adaptability, late bolting and strong regeneration ability. Cumin is mainly cultivated in various parts of Shandong Province.

2) fennel: the plant height is 30cm, the number of leaves is 5cm, the petiole is longer, the leaf distance is larger, the growth is fast and bolting is earlier. Shanxi, Inner Mongolia and other provinces (regions) more cultivation of fennel.

Introduction and control measures of fennel powdery mildew

Disease diagnosis of fennel powdery mildew:

It is mainly harmful to leaves and stems, which produce white powdery spots on the surface of stems and leaves at the beginning of the disease, then gradually expand and combine with each other, occupying most of the surface of stems and leaves, seriously covering the surface of the whole stem and leaves, and discoloration of the diseased tissue, resulting in local necrosis and death of the whole plant.

Pathogen of fennel powdery mildew:

It is a single living powdery mildew. The sporophore is erect and the upper part is gradually divided into conidia. Conidia subcolumnar, a few barrel-shaped, obtusely round at both ends, closed cysts generally scattered to nearly aggregated on the surface of stems and leaves, dark brown, oblate globose, 7-38 attached filaments, irregular branches and bifurcate branches, a few unbranched, 0-3 septum, nearly colorless, the base is mostly light brown. Ascus 2-5, individual up to 7, subovate or broadly ovate to subglobose, stalk short or absent.

The incidence regularity of fennel powdery mildew:

The pathogen in the warm area overwintered as conidia on the overwintering host, and in the cold area overwintered on the remnant with mycelium and closed cysts, and began to infect with ascospores or conidia in the spring of the following year. Seeds can also carry bacteria and spread over a long distance, and spores of pathogens in the field can be transmitted by wind and rain. The pathogen likes warm and humid conditions, the plant is closed, warm during the day, cool at night and dewy and humid environment is easy to occur.

Control measures of fennel powdery mildew:

The main results are as follows: 1) choose the land with high terrain and good ventilation and drainage.

2) using the seeds harvested by disease-free plants, the density is suitable, and enough organic fertilizer is applied to avoid excessive nitrogen fertilizer.

3) pay attention to ventilation, reduce humidity and increase light in protected areas.

4) do a good job in field sanitation and find the diseased plants in the center to be removed and buried in time. Thoroughly collect the disease and burn it during the harvest.

5) in the early stage of the disease, spray 1500 times of 15% verapamil wettable powder, or 3000 times of 25% enemy demulsifiable oil, 200 times of 50% sulfur suspension, 50 times of solid stone sulfur mixture, pay attention to spray evenly and fully.

Agricultural prevention and control

The main results are as follows: (1) rational fertilization, full mature organic fertilizer, and increased application of phosphorus and potassium fertilizer to improve plant disease resistance.

(2) the disease can be reduced by strengthening the planting density, strengthening the ventilation and reducing the humidity.

(3) Clean pastoral leaf disease plants should be thoroughly removed, taken out of the field, concentrated and buried or burned, so as to reduce the spread of pathogens in the field.

2. In the initial stage of physical prevention and treatment, 27% high fat membrane emulsion can be sprayed 100 times, once every 6 days, for 3-4 times. After spraying high lipid membrane, a very thin molecular membrane is formed on the leaf or stem, resulting in hypoxia and the death of powdery mildew. This molecular membrane is invisible to the human eye and can only be observed under an electron microscope.

3. In the initial stage of biological control, 2% Wuyimycin (agricultural anti-BO-10) water agent can be sprayed 200 times, or 2% antimycin (agricultural anti-120) water agent 200 times, once every 7 days, 2-3 times in a row.

4. When the disease control by pollution-free pesticides has just occurred (only a few plants and 1-2 small spots), 500 times of bicarbonate was sprayed immediately, once every 3 days, 5-6 times in succession. The application in the protected ground not only has a good effect, but also can decompose carbon dioxide and increase the output. The reason why baking soda can control powdery mildew is that powdery mildew bacteria like acidic environmental conditions, and baking soda is alkaline + spraying to change its environmental pH, resulting in the death of powdery mildew.

Chemical pesticide control:

At the initial stage of the disease, 20% triflon EC 1200-1500 times, or 25% triflon wettable powder 1500-2000 times, or 30% Teflin wettable powder 1500-2000 times, or 12.5% Supra wettable powder 2000-2500 times.

Or 70% colloidal manganese zinc wettable powder 500600 times liquid, or 40% polysulfide suspension 500x liquid, or 50% sulfur suspending agent 300400x liquid, or 20% dithione gel suspension 600,800x liquid, or 25% enemy demulsifiable oil 3000 times, spray once every 7 days, 2-3 times in a row.