Symptoms of potato blight, potato bacterial wilt affects yield, what are the symptoms of potato bact

Potatoes and what we usually call potatoes, which used to be vegetables, are now about to become staple foods. Its yield is very high, and it is also cultivated in many countries in China. However, in the process of its planting, there will be some threats of pests and diseases, not to mention the reduction of production, and the losses will definitely be not small.

Today's presentation is:

Potato blight has different symptoms due to different parts of the occurrence, and is also known as black nevus, black rough dermatosis and stem canker. It is a soil-borne disease that occurs severely. Potato sprouts were the most seriously affected, producing black-brown lesions on the buds, which gradually expanded and caused tissue necrosis.

Young roots, root hairs and stems are damaged, and black-brown lesion tissue necrosis is also manifested. Stem damage can injure the ductal system, causing the plant to wilt and eventually die. Because most of the diseased seedlings stand upright and die, it is called standing blight.

Tubers that are injured may vary in size and shape.

1. Prominent black patches, so it is called black mole disease.

Potato is a one- or two-year plant, generally propagated by tubers, weak root system, shallow distribution, cold and cool, afraid of frost, and not heat-tolerant. Soil temperature 5-7 when the potato pieces begin to germinate, to the temperature at 18 when the fastest germination, stem and leaf growth temperature of 20, if higher than 30, the stem and leaf small growth poor planting potatoes if not to take preventive measures, once the occurrence of bacterial wilt, it is very difficult. Because the disease is transmitted and multiplied from the roots and branches, the use of pesticides to spray sterilization is basically ineffective.

If the onset is mild, ditches can be dug in the potato growing land to drain the water.

High temperature, high humidity and rainfall are the main factors that induce the occurrence and epidemic of bacterial wilt, especially after rain, and the temperature of 30-37 degrees Celsius is the most conducive to the epidemic of the disease. Others, such as low-lying soil, heavy clayey soil, acidic soil, or continuous cropping with Solanaceae and other host crops, are also more serious1, choose disease-free seed potatoes to cut off the source of seed potato infection. 2. Implement crop rotation to avoid soil spread.

3. Use small whole potatoes to sow seeds to avoid the spread of knives. 4. The sowing period can be flexibly mastered to avoid the peak period of high temperature and rain. Different varieties had different resistance to potato bacterial wilt, and avoided continuous cropping with cruciferous and gramineous crops. Intensive cultivation in the field, for acidic soil, the field can be sprinkled with grass ash or quicklime to treat.

Prevention and control methods, the establishment of disease-free farmland and disease-free potatoes. In addition, it should be noted that it cannot be combined with Solanaceae, peanuts and other crops. Choose a field with high terrain and good drainage for planting, try to use organic fertilizer, and sprinkle some lime before ploughing the land to make the land slightly alkaline.

After the seedlings grow to about 10 cm, the whole field spray is carried out with cheap and efficient 80% mancozeb according to the instructions. Spray 3 to 4 times in stages. It can play a good role in protection and **.

For the prevention and control of potato bacterial wilt, we should first select disease-resistant varieties, select disease-free plots for seedlings, and implement more than four years of water-drought rotation with cruciferous plots or gramineous crops, and use high furrow cultivation to avoid flood irrigation in deep soil.

As a result of this change, the plants will grow shorter, and the color of the pharyngeal pieces will be lighter, and the leaves will shrivel, yellow, and finally rot, and the potatoes will be contaminated, and white pus will overflow.

The leaves will turn yellow or the roots will be starved and wilted, and this kind of situation may also be due to the collapse of water for a long time, or the lack of nutrients in the soil, so this kind of situation will occur.

The leaves withered rapidly, and then the leaves had a distinct color, and when the branches were cut, they were found to be empty, which was a very serious disease.

Late Blight: Potato late blight occurs mainly on the foliar surface and spreads to the potatoes over time. In the early stage of the disease, there will be some spots on the leaves, which will slowly turn brown, and in the case of dryness, the whole plant will slowly dry up and wither, and if the environment is relatively moist, the potatoes will begin to rot and stink.

Prevention and control: Detoxified potatoes can be used when sowing, and seed potatoes must be treated well before sowing, such as soaking seeds with Best wettable powder for 10-15 minutes, and sowing after drying. Cultivation management must be carried out strictly, and sowing must be done in loose soil and well-drained areas, and timely drainage and irrigation must be carried out to control the amount of nitrogen fertilizer.

In the early stage of the disease, you can use a concentration of 72% Best WP**, and use 600-800 times the liquid each time to spray.

Potato planting precautions.

When the sown potato tubers are sown at a depth of 10 cm below the ground and the soil temperature reaches 7 degrees to 8 degrees, the young shoots can grow, and at 10 to 20 degrees Celsius, the young shoots thrive and emerge quickly. The difference between the temperature of the sprout block and the soil temperature should be less than that during sowing, and the sowing should be stopped in too hot, too humid and too cold weather to prevent the bud from rotting. Pay attention to the temperature in the morning and evening, if the temperature does not allow it in the morning, sow it after the temperature is suitable, and end the sowing after the temperature does not allow it in the afternoon.

The sowing depth should be determined according to the soil quality and moisture, when the soil is loose, it should be sown deeply, the clay and the lower wetland can be appropriately shallow, the depth of 9-10 cm is easy, and the depth is 12-15 cm. According to the order of harvest and the climate of the year, the sowing depth should be appropriately adjusted, first shallower, then deeper, more rainy and shallower, less rainy and deeper.

Early blight. The lesions are brown to black-brown, with distinct whorls and a layer of black mold. The lesion is hard, generally does not rot, and sometimes cracks from the lesion in the later stage.

Sometimes it can also damage potato tubers, forming round or irregularly shaped, dark, slightly concave, and well-defined lesions. The potato flesh of the diseased part turns brown and dry rots in the later stage. Late blight.

Late blight is a fungal disease that is severe during the rainy season. At first, dark green water-stained lesions appear on the tip or edge of the leaf, and gradually expand, showing black-brown burnt spots, and in severe cases, they become burnt black, emitting a putrid odor. The lesions are slightly concave and grayish-brown, and there are rust-brown spots of different shades when cut.

Black shin disease. During the whole growth period of potato, its stems and tubers are affected by black shin disease. When the seed potato disease is severe, it rots before germination and cannot emerge, and there is a lack of seedlings and broken ridges in the field; Seed potatoes can emerge when the disease is light, and after the plant height is about 10 20cm, the symptoms are successively presented, that is, the diseased plant grows slowly, is short and erect, the stems and leaves gradually turn yellow, and the top leaves are curled to the midrib, especially when the temperature is dry, the wilting symptoms are more obvious.

First of all, when choosing soil, it is necessary to choose land where the soil is more fertile and wider than that of the sedan road. In the process of fertilization, we should choose farmhouse fertilizer, do not use fertilizer bought outside, and also water frequently, check the fan to prevent the occurrence of pests and diseases, if there is a small insect situation, then we must spray insecticides in time.

Potato bacterial wilt can be selected for disease-free varieties in this collapse, and the disease-free varieties and healthy small whole front traces are used for senji circle sowing, and the soil with deep soil layer and good air permeability is selected for sowing, so as to control the soil moisture content, find diseased plants, and remove them in time.

Be sure to know how to drain water after the rain. There should be a reasonable way to fertilize. To adjust the pH of the soil.

It is necessary to have a good ratio of pesticides, and then spray them before sowing after the number of deniers, so that it can also play a role in the prevention of burial. Crop rotation must be carried out on particularly diseased soils. Choose some disease-resistant varieties.

Potatoes mainly have early blight and leaf spot.

1. Early blight travel

The disease mainly affects leaves and tubers, and when the leaves are damaged, there will be scattered small brown spots, which will then expand into irregular concentric rings with narrow faded halos around them. Black mold will appear in a humid environment, and the leaves will dry up and fall off in the later stage.

Prevention and control methods: select early-maturing and disease-tolerant varieties, choose high terrain and fertile soil for planting, and increase phosphorus and potassium fertilizers, and remove diseased branches in the field in time through reasonable dense planting, which can effectively reduce the source of disease in the field. After the onset of the disease, mancozeb, zepzeb, difenoconazole and other agents can be used for spray prevention and control, and the effect is very significant.

2. Leaf spot

The disease mainly affects leaves and underground tubers, with initial yellow or light brown round lesions, and in humid environments, gray mold layers will appear, and conidia of pathogenic bacteria will be produced.

Prevention and control methods: the implementation of rotation deep ploughing, can effectively reduce the harmful pathogenic bacteria in the soil, after the onset of the disease, you can use 50% carbendazim vanmycolin wettable powder 1000 1500 times liquid, or 75% chlorothalonil wettable powder 600 times liquid spray control, spraying once every 7-10 days, can play a good control effect.

Potato planting precautions.

It is best to choose loose soil, fertile, well-drained and well-ventilated Manchuan Mangang land, suitable for mechanized operation, slightly acidic or neutral sandy loam soil is suitable. If the soil is hard and the aeration is poor, the growth of potato tubers is restricted, resulting in small tuber growth, rough surface, and deformity, which in turn directly affects the yield and quality.

When cultivating in the field, it should be noted that the front stubble is the ground banquet block of soybean stubble, and do not choose the plot that has used sulfonylurea herbicides such as beansulfuron, bean B mixture or Pusit, golden bean and other herbicides as stubble, otherwise it is easy to cause potato pesticide damage and reduce yield.

2) Avoid high temperature and high humidity conditions. (3) At the beginning of the disease, spray 500 times of 36% thiophanate-methyl suspension macro-only agent or 500 times of 50% polysulfur suspension, 500 times of 50% thiophanate-methyl wettable powder, 800 times of 50% carbendazim wettable powder, 800 times of 80% anthrax Fumei wettable powder, 1000 times of 70% thiophanate-methyl wettable powder and 75% chlorothalonil-methyl wettable powder l000 times, and the control effect is better than that of the above-mentioned fungicides alone.