Cauliflower downy mildew often occurs, what are the symptoms of cauliflower downy mildew?

It mainly occurs on cauliflower. In the early stage of the disease, there are water-soaked small spots on the tips and margins of the inner bulbous leaves in sensitive leaves, and then they become scorched and browned, and the leaf margins are similar to "burns". If there is soft rot bacteria, it will quickly rot wet, or even "rot away"; If no other bacteria continue to infiltrate, it is dry membranous (dry heartburn).

At first, there will be some pale green lesions on the foliage, and then these lesions will gradually expand to yellow or brown. If it is severe, there will be a lot of lesions on the back of the leaves, which will eventually cause the leaves to dry up.

The initial pale yellow-green lesions with inconspicuous edges on the leaves, then turn yellow to yellow-brown, often limited by the leaf veins into polygonal shapes, and in severe cases, the lesions are continuous, and the diseased leaves die. On the back of the diseased leaves, there is dense white frosty mold.

There will be a lot of patches on the leaves, and most of these patches are white, and there are also some molds that appear, and there will also be deformities on the plants.

Broccoli is also a delicacy on our table, what precautions do we need to take to grow broccoli? In order to effectively prevent the invasion of pests and diseases! Broccoli, also known as cauliflower, is a common green vegetable that belongs to the cabbage series.

Broccoli has high nutritional content and is known as the "vegetable crown", and is planted in rural areas in the north and south of China. Before planting, it is recommended to spray seedling refining and rooting powder of Hansheng Company to prevent root rot, black shin disease, and blight that are prone to occur after planting.

Symptoms of cinerine mold in vegetables. The disease is mostly from the leaves close to the surface, the initial disease part is water-soaked, and the disease part expands rapidly when the humidity is high, and it is brown or light reddish-brown, causing rot, and the disease part has gray mold. The base of the stem is diseased, the diseased part becomes brown and rotten, and the control method is to select soil for 2 to 3 years of rotation.

Choose new seedbeds or field seedlings without pathogenic bacteria to cultivate disease-free and strong seedlings. In the morning of cultivated in the protected area, the humidity should be reduced by wind, then the shed should be closed to increase the temperature, and the humidity should be reduced to below 75% in the afternoon.

In the process of planting vegetables, it is very normal to encounter a variety of diseases, especially nightshade crops are very easy to get gray mold, this disease also makes people very headache, high temperature and low humidity are very easy to attack, vegetables are indispensable for human survival, we mainly eat cabbage, tomatoes, eggplants, peppers, cucumbers, etc., now in order to meet the needs of the market, vegetable types are very diverse, such as new fast vegetables, chrysanthemums, etc., some I can't name.

The recurrence of vegetable gray mold may be due to excessive sitting, which causes a large number of pathogens to accumulate in the soil, and a large number of diseases occur when the pathogens develop in the environment. To prevent this from happening, we need to adopt a variety of means. Agricultural control:

In crop rotation, many vegetables will develop gray mold, such as tomatoes, peas, peppers, cucumbers, etc. Vegetables, leaves, fruits, stems, and flowers will be damaged, and in severe cases, the entire vegetable plant will dry up, causing heavy losses.

In such a situation, pesticides should be sprayed in time, and the right medicine should be prescribed, and fertilizer should be supplemented in time, water and fertilizer management should be strengthened, and some sterilization drugs should also be sprayed, and insect pests should also be removed in time to ensure sufficient light.

First of all, it is necessary to clean up the weeds in time, and we must decompose and remove the disease residues in time, and we must adopt the method of water and drought rotation, and then we must choose some better varieties, and we must spray insecticides in time.

In autumn and early spring, the sick and debris should be completely removed, and buried or burned in a concentrated manner to reduce the source of bacteria.

Reasonable dense planting, timely drainage after rain, pay attention to reduce the humidity of the field, keep it away from the disease conditions.

Brown spots or sunken spots appear on the cotyledons of downy mildew of cabbage, yellow polygonal lesions appear on the true leaves, and white mold layers appear on the back of the leaves and on the stem of the seedlings when wet. When the disease is severe, the cotyledons and young stems dry up and die. Apply foot fertilizer, timely top dressing and foliar fertilizer spraying, avoid partial application of nitrogen fertilizer, and improve plant disease resistance; Moderate watering, flood irrigation and noon watering on sunny days, water is indispensable after wrapping the heart; Diseased plants were uprooted in time in the field, and diseased residues were removed after harvest to reduce re-infection during the cellar period.

Downy mildew of cabbage generally occurs first in the outer leaves and gradually expands to the inner layer. From sporadic onset to field-wide common onset, leaf onset presents yellow spots on the front of the leaf and produces hoarfrost mildew on the back, that is, the sporangia of the pathogen. When the disease is severe, the mold layer covers the entire leaf, and finally the diseased part is yellow-brown to dark brown and withers and dies. The disease of the remaining seed plant, the leaf symptoms are the same as that of the adult plant, the flowers, peduncles, and seed pods are deformed and swollen, twisted like a dragon head, and there is a white frosty mold layer on the surface, and there are few or no seeds.

The affected part of the stem and peduncle also showed white sparse mold layer symptoms.

Scientific prevention and control can implement high and narrow furrow deep furrow cultivation, sowing at the appropriate time, reasonable dense planting, and preventing field canopy; Apply foot fertilizer, timely top dressing and foliar fertilizer spraying, avoid partial application of nitrogen fertilizer, and improve plant disease resistance; Moderate watering, flood irrigation and noon watering on sunny days, water is indispensable after wrapping the heart; In the field, the diseased plants were uprooted in time, and the diseased residues were removed after harvest, so as to reduce the symptoms of re-infection at the seedling stage at the cellar stage At the beginning of the disease, there was a white frosty mold layer on the back of the leaves, and there were no obvious symptoms on the front of the leaves.

Downy mildew refers to the plant disease caused by downy mildew in the fungus, downy mildew is an obligate parasite, and a very small number of downy mildew can be artificially cultivated, such as the grassy finger fungus that causes millet white disease, and the parasitic downy mildew that causes downy mildew of cabbage. It is easy to be complicated by horn spot disease, and when the air is humid, a frosty mold layer is formed on the back of the leaf, which can sometimes spread to the leaf surface. In the later stage, the lesions die and die, yellowish-brown, and in severe cases, all the outer leaves wither and die, similar to Verticillium wilt.

White mold will appear on the back of the cabbage stalk at the larval stage of downy mildew of cabbage, and the mold will turn yellow-brown at the adult stage and spread to the stem and leaf part, and the leaves will turn yellow and rot. Prevention of cabbage downy mildew should start from seed selection, select insects that are resistant to diseases and insects, and do a good job of soaking seeds before sowing to prevent pests and diseases.

Downy mildew of cabbage is manifested by dry rotten leaves and black roots. Scientific control methods can use green vegetable plants before the maturity of grass and wood ash ditch ridge vegetables, and can also use Hu Nandan to sprinkle in the soil of the roots of vegetable plants.

The first point is the symptoms, which is that there are a lot of white dots on it, the second point is that there are a lot of black dots on it, and the third point is that there are a lot of bugs that are scary.

Oilseed rape is rotated with grasses such as barley and wheat for 1 2 years, or water-drought rotation; select high-yielding and disease-resistant varieties suitable for local planting; Select disease-free plants before harvesting, or carry out seed treatment before sowing; Sow seeds at the right time and plant them reasonably densely to facilitate ventilation and light transmission in the field; Do a good job in water and fertilizer management, apply sufficient base fertilizer, promote strong seedlings, increase phosphorus and potassium fertilizer, enhance plant disease resistance, and require deep ditches and narrow compartments, clear ditches and drain stains; Pharmaceutical control: 80% mancozeb wettable powder 500 times dilution (1 kg of medicine plus 500 kg of water), 40% aluminum triethylphosphonate wettable powder 200 300 times dilution, 64% frost? The 500-fold dilution of manganese-zinc wettable powder was sprayed every 7 10 days after the onset of rapeseed disease, a total of 2 3 sprays.

Vegetable downy mildew control methods:

1.Agricultural control:First, the seriously ill field should be rotated for 2-3 years.

Apply enough well-rotted organic fertilizer to improve the disease resistance of plants. The second is reasonable dense planting, scientific watering, to prevent flood irrigation, in order to prevent the spread of diseases with the flow of water. Strengthen the ventilation and reduce the humidity.

Third, if it is found that the diseased plant infected by downy mildew fungus, it should be pulled out in time, taken out of the field to burn or buried deeply, and at the same time, sprinkle quicklime to treat the planting hole to prevent the spread of the source of disease. At harvest time, the leaves of the residual plants are completely removed and taken out of the field to be buried or burned.

2.Pharmaceutical prevention and control. It can be sprayed with 500 times of 75% chlorothalonil wettable powder at the beginning of the disease, and 500 times of 58% methyl frost and manganese-zinc wettable powder or 800 times of 69% enoyl-manganese-zinc wettable powder when the disease is severe.

Spraying once every 7 days, continuous control 2 3 times, can effectively control the spread of downy mildew. At the same time, it can be combined with spraying foliar fertilizer and plant growth regulators for control, and the effect is better.

If it can't be covered, it should be done first and then covered to avoid aggravation of the disease.

The maintenance of cauliflower is envied in a macro way.

Soil: Cauliflower prefers loose, airy, well-drained, acidic soil.

Light: It loves light, and the right light will make it grow better.

Watering: Water every 3-5 days in summer, spring and autumn, and every 7 days in winter, and do not allow water to accumulate in the soil.

Temperature: It likes a warm environment, the most suitable growth temperature is 14-24, too high a temperature is not conducive to its growth.

Fertilization: It likes fertilizer, and the state can apply more fertilizers with higher nitrogen content to it during the growing season, and you can also use water-soluble fertilizers with fertile leaves.