What are the causes and control methods of potato wilt?

The pathogen of potato wilt is Fusarium azirum, which is a soil-borne fungal disease on potatoes, widely distributed, commonly occurring in various planting areas of the country, and the disease is serious in heavy crops, which poses a threat to potato production, and the pathogen is complex, the genetic variability is large, and the stress resistance is strong, which increases the difficulty of the prevention and control of the disease.

1. Harmful symptoms of potato wilt.

At first, the aboveground part of the blight appears wilted, the diseased stem is cut, the vascular bundle of tubers turns brown, and when the humidity is high, the diseased part often produces white to pink hyphae. Initially there are greenish spots between the veins of young leaves, and then necrosis of the greenish zone. The leaves of the diseased plant are bronze-colored, wilted, withered, and hang on the stem without falling off.

2. Occurrence law.

The fungus overwinters in the soil or on diseased potatoes with mycelium or pachygaki spores. The following year, the conidia produced by the diseased area are transmitted by rainwater or irrigation water and invade the wound.

3. Onset conditions

The disease is prone to high humidity in the field, soil temperature higher than 28, or heavy stubble and low-lying land.

4. Prevention and control methods Agricultural control advocates 4-year crop rotation with gramineous crops or green manure.

Choose disease-resistant varieties. In potato production, disease-resistant varieties are selected to improve plant disease resistance and control disease attacks.

Sterilization and insecticidal soil, 250 grams of 70% methyl isosulfonate per mu, mixed with 30 kg of dry fine soil, and then mixed with 25% chlorothalonil 250 grams, mixed well, applied into the planting ditch and then planted potato pieces.

In the planting process, the cultivation mode of high ridge mulch film can be adopted, reasonable and dense planting, and strict requirements on planting density.

In terms of irrigation, it is necessary to carry out reasonable irrigation to avoid heavy watering and damage to plants. Drain and clean the rainwater in the field in time to avoid the spread of bacteria and infection.

Increase the application of well-rotted organic fertilizer, phosphorus and potassium fertilizer, and prevent the partial application of nitrogen fertilizer.

Remove the disease and residues in the field in time after harvesting.

Chemical control. At the beginning of the disease, spray 50% carbendazim wettable powder 600 times, or 50% diphthofen; WP 1000 times liquid. It can also be used to control the disease with 600-1200 times liquid spray of Kekudan, and then use Oxachlor, 30% Methyl Frost and Oxazalin for prevention and treatment.

Soil disinfectants, such as carbendazim or pentachloronitrobenzene, can be applied to planting belts to reduce the incidence of disease.

Malnutrition, when the potatoes are fruiting, the right amount of top dressing, can better absorb the crops, so that they can grow better.

Hello dear, the main reasons for the occurrence of potato wilt are: the variety itself has poor disease resistance or no disease resistance, which is conducive to the invasion of pathogens; Seed potatoes or diseased residues carry bacteria, and the amount of bacteria source is sufficient; The climatic conditions are suitable, with high temperature and high humidity, which is conducive to the growth and development of pathogens and the invasion of diseases.

Summary. Biological control Trichoderma harzianum T22 strain can inhibit the growth of some fungi such as Sclerotinia sclerotinia and Pythium of crops, and use it to treat seeds, irrigate greenhouse soil or carry out furrow application, which can colonize all parts of the crop root system, and can be maintained for a long time, and has obvious control effect in greenhouses and fields.

Biological control Trichoderma harzianum T22 strain can inhibit the growth of some fungi such as Sclerotinia sclerotinia and Pythium in crops, and use it to treat seeds, irrigate greenhouse soil or carry out furrow application, which can be planted in all parts of the crop root system with high reputation, and can be maintained for a long time, and has obvious anti-qi effect in greenhouses and fields.

Potato dry rot, also known as "wilt", is a fungal disease, which can occur in the process of tuber swelling and vertical destruction, harvesting, transportation and seed potato cutting. At the beginning, the skin of the tuber was dark and brown, and then the diseased part was slightly concave, gradually forming folds and shrinking in the form of concentric rings. In the later stage, the inside of the tuber turns brown, often hollow, and the cavity is covered with hyphae; Eventually, the flesh turns grayish-brown or dark brown, stiffened, dry rot, lightened, and hardened. When the diseased potato is opened, the hollow is covered with mycelium, and the inside of the potato becomes dark brown or grayish-brown, and finally the whole tuber is stiff or dry rot, and it is inedible.

Hello dear, I am glad to answer for you, the use of biological agents to prevent and control potato wilt, the effect is good, but also to avoid the occurrence of pesticide damage. Potato wilt can show symptoms before and after the flowering period, the lower leaves of the plant wilt at the beginning of the disease, like lack of water, especially at noon under the slow or strong light is more obvious, morning and evening can be recovered. Then it gradually expands from the bottom to the upper leaves, and finally the root cortex rots, and the whole plant wilts or even dies. When the diseased stem is dissected, the vascular bundles turn brown, and the pathogenic bacteria can enter the grooming tissue of the tuber through the stolon, and form a dotted line brown ring in the vascular bundle of the tuber, but it does not decay.

Occurrence and control technology of potato wilt.

1.Symptoms Potato wilt is a systemic infectious disease, in the early stage of the disease, the shoots appear wilted, the diseased stems are opened, the vascular bundles of potato tubers turn brown, and when the humidity is high, the diseased parts often produce white to pink hyphae. 2.

Pathogenesis and conditions The pathogen overwinters in the soil or on diseased potatoes with mycelium or thick-walled spores along with the diseased residues. In the following year, when conditions are right, conidia are produced in the diseased area, which are transmitted by rainwater or irrigation water and invade the wound. The terrain is low, the soil is clayey and heavy, it is easy to accumulate water after rain, the planting density is too large, the field permeability is poor, the management is extensive, the growth of the plants lacking fertilizer and water is poor and the disease is serious.

3.Control methods: Crop rotation with gramineous crops for more than 2 years; Choose plots with relatively flat terrain and not easy to accumulate water for cultivation, reasonable dense planting, strengthen fertilizer and water management to promote the healthy growth of plants, and remove water accumulation in the field in time after rain; Remove the disease and residues in the field in time after harvesting. From the onset of the disease to the early stage of the disease, the following fungicides or formulations can be used for prevention and control:

5 Acrylic Acid, Evil Mold, Nail Cream Water Agent 800?100 state tones; 80 more than Fu Fu zinc wettable powder 500-700 times liquid; 5. Salicylylamine wettable powder 300-500 times; 50 Benomyl WP 1000 times 50 Fumei double wettable powder 500 times liquid; 70 Blessed with a brimstone is wet.

Potatoes are a high-yielding cash crop, but they are also disease-prone crops. Disease has become an important factor affecting potato yield, today we will learn about potato wilt and how to control it.

1. Symptoms of potato wilt Potato wilt is a typical soil-borne disease, which is mainly manifested on the leaves in the early stage, and the leaves of potatoes begin to turn yellow from the tip of the leaf to the leaf edge, and then yellowing from the leaf veins to the inside. Then the whole leaf turns from yellow to brown and then withers, and then the compound leaves of the whole plant all wither, but the leaves do not curl and do not fall off.

When the leaves turn yellow, it can be seen that the vascular bundles at the rhizome have browned, and then gradually spread to the aboveground parts, causing the vascular bundles of the aboveground stems to also brown. Cut the diseased potatoes and see the "figure-eight semicircular discoloration ring".

2. Pathogenesis conditions for potato wilt The pathogens of Fusarium wilt can survive the winter in the soil, infected straw and infected potato tubers, and infect potatoes in the spring of the next year. Fusarium wilt multiplies within the vascular bundles and spreads throughout the plant.

There are two main ways of transmission of wilt, one is the tuber with the fungus, which will spread into the plant after planting. Second, the pathogens in the soil spread to the plants after infecting the tubers.

From sowing to flowering is the frequent occurrence period of potato wilt, the temperature is low after sowing, the wound healing of seed potatoes is slow, and it is easy to be infected with disease. Before flowering, if there is a persistent low temperature below 15 degrees Celsius, it is also prone to disease. It is also easy to develop diseases in low-lying plots, or in plots with improper drainage and even production.

3. Potato wilt prevention and control methodsAfter understanding the symptoms and conditions of potato wilt, effective control measures can be taken. For blight, we focus on prevention and control to prevent the spread of germs. In the early stage of the disease, timely medication has a better effect, so let's take a look at the specific prevention and treatment methods.

1) Crop rotation with non-Solanaceae plants can reduce the occurrence of diseases.

2) Choose detoxified potato pieces without pathogens to prevent disease infection in seed potatoes.

3) Before sowing, use carbendazim to mix or soak seeds, and then sow after drying.

4) For severely diseased plots, use carbendazim for soil disinfection.

5) In the early stage of the disease, drugs can be used for prevention and control, and different concentrations of carbendazim can be used for foliar spraying or root irrigation.

Before potato planting, turn over the ground and sprinkle fertilizer to kill soil pathogens per acre, and then rotary tillage and plough the ground, and after the potato grows to four leaves, each mu is filled with 20 kg of humic acid, and the foliar spray wilt must treat the growth regulator gibberellin to accelerate the growth, once in 15 days, twice in a row, basically eliminate the blight disease, and lay a solid guarantee for the harvest.

Before ploughing the ground, each mu is sprinkled to kill soil pathogens, and then rotary tillage ploughs the ground, after the potato grows to four leaves, each mu is filled with 20 kg of humic acid, and the foliar spray of the blight must cure the growth regulator gibberellin to accelerate the growth, once in 15 days, twice in a row, basically eliminate the blight disease, and lay a solid guarantee for the harvest.

Establish disease-free farmland, and select disease-free roots for seed potatoes. After planting, strengthen field management and pine cultivated land, maintain good ventilation in the field, and prevent the emergence and spread of root rot. For plants that have already developed the disease, flushing or irrigating the root microbial agent root boy can play a good treatment effect, regulate the soil, and reduce soil-borne diseases.

Soil disinfection, soil disinfection before sowing, selection of disease-resistant varieties. The selection of resistant varieties is an effective measure to prevent Fusarium wilt infestation.

First of all, before ploughing, sprinkle fertilizer to kill soil pathogens on each acre, and then rotary tillage plough the ground. Secondly, the implementation of land rotation should not be planted continuously, and crop rotation planting should be carried out to reduce the incidence of wilt.

Land rotation is the best way to prevent blight! Try not to plant continuously, and if possible, you can carry out crop rotation planting to reduce the incidence of Fusarium wilt and improve economic benefits!

Good evening 1Crop rotation and stubble: Crop rotation with cereals, other grasses or leguminous crops for more than four years, not with Solanaceae crops.

2.Breeding and planting disease-resistant varieties and retaining disease-free seed potatoes.

3.Exterminate susceptible weeds, such as dandelions, shepherd's cabbage, etc.

4.Farming practices should be carried out in a way that reduces root damage and combines the elimination of nematodes and underground pests. Apply compost made of enzyme bacteria or fully decomposed organic fertilizer, avoid partial application of nitrogen fertilizer, increase phosphorus and potassium fertilizer, and improve plant disease resistance.

Timely irrigation, timely removal of stagnant water in the field after rain. Remove diseased plants in time, remove diseased residues after harvest, and reduce the source of infection.

5.From the onset of the disease to the early stage of the disease, the following fungicides or formulas can be used for prevention and control: 5 acrylic acid, evil mildew, nail cream water agent; 80 more than Fu Fu zinc wettable powder 500-700 times liquid; 5. Salicylylamine wettable powder 300-500 times; 50 Benomyl WP 1000 times 50 Fumei double wettable powder 500 times liquid; 70 Blessing, A, sulfur, etc.

FYI.