Broccoli black spot affects yield, what are the symptoms of broccoli black spot?

At first, there will be some small spots and small black spots on the leaves, and then they will begin to turn brown and gradually necrotic with this small class as the center, and after the lesions gradually expand, they will become round lesions. When the temperature is high, it will turn into gray-brown or gray-white large round spots, and there will also be yellow halos nearby, which will produce black-brown mold, and often perforated.

Small black holes appear in the leaves of broccoli, and the leaves often die directly. It is also grayish-brown or yellowish-brown. Small round spots often appear.

It also produces black-brown mold. The surface of the cauliflower will also be concave, and the fruit will be very thin and not firm at all. If broccoli encounters this symptom, it must be treated promptly.

Onset begins in the outer lobe. Initially water-stained, the spots develop into brown to black dots, and when temperatures are high, the spots quickly expand into gray-brown round lesions.

Broccoli flowers with black spots on the flower should have black rot, > black rot is the first to damage the leaves, the fungus invades from the water hole, mostly appears from the leaf edge, and then extends inward to form a "V" shaped yellow-brown blight, which often has a yellow halo around the lesion; Sometimes the fungus expands inward along the leaf veins and produces large yellow-brown spots or the leaf veins turn black and reticulated, and if the bacteria invade from the wound, they can form irregularly shaped yellow-brown lesions on any part of the leaf. Classified as a bacterial disease.

Prevention and control method: streptomycin can be used.

Phyllazole, octenamine, mesomycin, thiamium copper, thioxensen copper, quinoline copper, chlorbromoisocyanuric acid.

Bacillus polymyx, etc. plus potassium dihydrogen phosphate of Trim.

Spray control, spray 2 to 3 times in a row from 5 days.

Broccoli is a common food, regular consumption of broccoli can **menstrual irregularities and**itching and other symptoms, and broccoli also has the effect of replenishing qi. Regular use by the elderly can also alleviate the symptoms of the three highs. Broccoli black spot, also known as black mold, mainly affects leaves, stems and petioles.

Leaf disease usually starts at the outer edge of the leaf and progresses to water spot disease, followed by brown spot and black spot disease. When the temperature is high, the lesions rapidly expand into grayish-brown round lesions.

Under humid conditions, the lesions are large, 5-30mm in diameter, and the lesions have black mold. When there are many diseased spots on the leaves, it merges into large spots. When there are many leaf spots, it is easy to turn yellow and wilt early.

Generally in the middle and late stages of growth, if the weather continues to rain, or if the fertility is insufficient, the disease is severe. The stem and petiole are infected, and the lesions are long fusiform, dark brown, banded, and depressed, which can be controlled by pesticides such as PFLP, chlorothalonil, and mancozeb. When the seeds are dry heat treated at 78 hours, the virus can be killed for 48 hours.

Adjust the planting layout, reasonable intercropping, intercropping, crop rotation, and remove diseased plants in time.

The sowing period should be early, avoiding high temperatures and aphid rampant seasons; Covering with insect nets can prevent and control aphids at an early stage, reduce transmission and control diseases. Organic base fertilizer and water application are often increased. In the early stage of the disease, 500 times of 20% virus A wettable powder, 1000 times of cough emulsion or 600-800 times of virus bicycle wettable powder can be sprayed alternately, and foliar fertilizer can be sprayed at the same time to enhance plant disease resistance.

Broccoli is rich in calcium and vitamin K, which promotes the calcification of bone tissue and inhibits bone resorption caused by osteoclasts, thereby increasing bone density. The presence of calcium in broccoli has a good effect on the prevention and treatment of osteoporosis.

Broccoli is rich in ascorbic acid, which can enhance the liver's detoxification ability and improve the body's immunity. Broccoli is effective against breast and colorectal cancer. Healthy people often eat broccoli can also play a role in preventing cancer.

Broccoli can regulate and prevent high blood pressure and heart disease. Broccoli is rich in fiber, which can effectively reduce the absorption of glucose in the gastrointestinal tract, thereby lowering blood sugar and effectively controlling the condition of diabetes. Broccoli is a gospel food for diabetics.

We can use 50% iprodione wettable powder 1000 1500 times liquid **, which can be sprayed every 7 10 days.

Pesticides should be sprayed in a timely manner, and the right medicine should be prescribed, and the ratio of pesticides should also be paid attention to, and weeds should be removed in time, and the management of water and fertilizer should be strengthened, and sufficient sunlight and soil permeability should also be ensured.

The effect of gram wettable powder is very good, and it can also be treated with organic fertilizer, and it will not cause damage to the farmland.

In the open field or shed, spray 1000 1500 times of 50% promethane wettable powder or 600 times of 75% chlorothalonil wettable powder and 600 times of 80% spray wettable powder before the onset of the disease. The key to the effectiveness of the above-mentioned protective agents lies in the sooner or later they are used. If the disease spot is not visible before the onset of the disease, the prevention effect is more than 70%; Although the drug has a certain inhibitory effect after the onset of the disease, it is not ideal.

Therefore, it is emphasized that prevention and treatment should be started before the onset of the disease, the source of bacteria in the early stage should be suppressed, and the disease should be controlled below the economic damage index. Discontinue the drug 7 days before harvest.

There are also particularly obvious ring patterns on the lesions, and when the humidity is high, it will be equipped with a grinding to promote the spread of the lesions, so that the whole leaf will be diseased and finally die; Leaf state and stem infections appear as oval or long fusiform depressed spots that are brown in color. The middle part of the pod infection is grayish-white, with brown edges, and gray-brown mold piles appear in the diseased part when the humidity is high. The color will be darker and deeper, and it will be expanded.

The pathogens are mainly in the stumps and soil planted before, and this kind of disease has a good latent nature, so we should take certain measures to prevent it.

The pathogen overwinters on the residues of diseased plants and seeds with mycelium and conidia. The following year, it spread through wind and rain. The appropriate temperature for the onset of disease is 13 15, which is conducive to the occurrence of diseases under the conditions of low temperature and high humidity.

In addition, early sowing, slow and late rain, and extensive management are also conducive to the epidemic of diseases. Resistance also varies among different varieties. After about 3-5 days, the conidia begin to grow and develop.

The mature bacteria produce new conidia, which again invade the surrounding tissues and expand the scope of the disease. The optimal temperature for the onset of black spot disease is 12 20 and the relative humidity is 75 85%, the higher the humidity

When the disease is severe, multiple lesions converge into large spots, causing half or the whole leaf to turn yellow and die, and the whole leaf to dry up from the outside to the inside. The lesions on the petiole and peduncle are long fusiform, dark brown, slightly concave: the lesions on the seed pod are nearly round, **gray, brown on the edges, light brown on the periphery, with or without wheel stripes, when the disease is severe, multiple lesions converge into large spots, resulting in half or the whole leaf turning yellow and dying, and the whole leaf drying up from the outside to the inside.

Lesions on petioles and peduncles are fusiform, dark brown, slightly concave: lesions on seed pods nearly rounded, **gray, brown on margins, light brown on periphery, with or without whorles, <>

When the disease is severe, multiple lesions converge into large spots, causing half or the whole leaf to turn yellow and die, and the whole leaf to dry up from the outside to the inside. Lesions on petioles and peduncles are fusiform, dark brown, slightly concave: lesions on seed pods nearly rounded, **gray, brown on margins, light brown on periphery, with or without whorles, <>

When planting, choose land with relatively fertile and wide soil. And in the process of fertilization, you must choose farmhouse fertilizer, do not use the fertilizer you bought. And the auspicious match should be watered more.

It is also necessary to prevent the occurrence of pests and diseases, and if there are small insects, then you must spray insecticides in time.

Be sure to spray more pesticides, be sure to spray more potassium permanganate solution, and pull out all the excess cauliflower, be sure to ventilate more.

You can apply an appropriate amount of pesticides, and ensure the nutrition of the fertilizer, ensure the appropriateness of the amount of water, and do not apply too much fertilizer or watering.

The soil is not loose and breathable, the soil has no nutrients, and the air humidity is particularly high, and there is a lack of fertilizer.

Even if there is continuous rainy weather and the fertility of the soil is not enough, it will be easy to cause such dark spot disease.

Broccoli black spot, also known as black mold, mainly damages leaves, stems, and petioles. The leaf disease usually starts from the outer leaves, which are water-stained dots at first, and then develop into brown to black dots, and the lesions rapidly expand into gray-brown round lesions when the temperature is high. Under humid conditions, the leaves are the main part of the black spot disease, and its surface and lower leaves are susceptible to the disease on the front or back.

At first, it is a nearly round green patch, the diameter of the infection is 1 10 mm, and the black spot mainly affects the leaves, petioles, peduncles and horns of broccoli. Both seedlings and adults can be damaged. The leaves are damaged, showing nearly circular green spots at first, and after enlargement, they are dark brown in the middle, pale green on the edges, with or without obvious wheel lines.

When wet, the surface is densely covered with black mold.

Black spot disease can occur in all growth stages of broccoli, mainly infecting leaves, and in severe cases, it also harms stems, petioles, flower bulbs and seed pods. The plant disease is mostly developed from the old leaves to the young leaves, in the early stage of the leaf surface or the back of the leaf there are green spots or small black spots, and later the disease spots ** turn brown and necrosis, light requirements: broccoli is not very strict with light requirements, but in the growth process like sufficient light, the plant grows robustly, can form a strong nutrient body, is conducive to photosynthesis and nutrient accumulation, and makes the flower bulb compact and dense, <>

After harvesting, remove the diseased residue in time, turn it deep in time, adopt formula fertilization technology, properly control watering and increase phosphorus and potassium fertilizer when the bulbs grow to the size of a fist. For example, topdressing superphosphate, plant ash, bone meal, etc., can enhance disease resistance. Broccoli prefers to be planted on soils with plenty of sunshine, strong fertilizer and water retention, loose and fertile, good air permeability, pH value of 6, and good drainage.

Therefore, the cause of root rot is often related to the soil, which is low-lying, heavy soil stickiness, and poor drainage.

At a certain seedling age, the flower buds begin to separate flowers at low temperatures, and the appropriate temperature for seed germination is 20 to 30 degrees, and the appropriate temperature for growth and development is 15 to 18 degrees. Higher temperatures are required in the early stages of growth, 18 to 25 °C, and lower temperatures are required in the later bulb formation periods.

Broccoli horn spot disease mostly occurs in areas with warm winter and spring, fog and heavy dew. Greenhouse cultivation is also prone to disease if the humidity is high.

Broccoli horn spot disease mainly damages leaves. At the onset of the disease, polygonal lesions appear on the leaves, light grayish-white. The edges of the lesions are clear, and some lesions have brown edges.

It may be due to a fungal infection, a lack of crop rotation, a lack of pesticides at the beginning of the disease, or a lack of fertilizer or water.

This may be due to a lack of nutrients in the soil where the broccoli is grown, as well as a lack of water and fertilizer during the planting period.

Broccoli, purple cabbage leaves, stems, peduncles, seed pods can be infected, the leaves are infected with a large number of small spots with light brown to purple edges, the diameter is very small, the large ones can reach centimeters, when the necrotic spots are fused to form large irregular necrotic spots, up to centimeters or more, the lesions initially appear in large numbers on the back of the leaves, and each spot occurs at the stomata. The fungus can also damage the leaf veins, causing the leaf growth to slow down and the foliar surface to shrink and further expand; When the humidity is high, oily spots are formed, brown or dark brown, enlarged to black-brown, unshaped or polygonal, like thin paper, and the outer leaves occur more at first, and then spread to the inner leaves; The stems and peduncles are infected, initially with small oily spots, then purple-black streaks, and the lesions on the pods are round or irregularly shaped, slightly concave. Broccoli (broccoli) mainly harms broccoli (broccoli) leaves.

Small dark green dots appear on the back of the leaf first, water-stained. <>

Gradually develop into nearly circular necrotic spots, grayish-brown to dark brown, ** distinctly concave, often with water-stained dark green halos on the edges. The lesions on the leaf surface are irregular, grayish-brown to dark brown, with darker, oily edges. A plurality of lesions are connected to each other into necrotic plaques, which are easy to break and perforate when dry, resulting in leaf necrosis, and all leaves of the plant can be infected when the disease is severe.

For example, high temperature and humidity are conducive to the onset of the disease. Long-term rain, fog, long time of dew condensation in the field, severe disease. The management is extensive, the soil is poor, and the disease is severe.

Choose disease-resistant varieties. Carry out crop rotation with non-cruciferous vegetables for more than 2 years, remove the disease residues in time after harvest, and bury or burn them in a concentrated manner. Establish disease-free seed land, and the infected seeds can be mixed with 50% copper succinate fertilizer (dt) wettable powder of the seed weight, or 50 100 grams of Fengling mixed with 150 grams of cabbage seeds and then sown.

A small number of diseased plants were found to be pulled out in time, and 400 times of 30% green debao suspension or 3000 4000 times of 72% agricultural streptomycin sulfate soluble powder and 600 times of 27% copper noble suspension were sprayed at the beginning of the disease, and 40 50 liters of good liquid were sprayed per 667 square meters. Cabbage is sensitive to copper, and the dosage should be strictly controlled to avoid pesticide damage, and it is not suitable to spray at noon in the hot afternoon. Discontinue the drug 3 days before harvest.