What is the disease of peanut rotten roots and yellow leaves, and what should I do if there are many

Peanut root rot <>

Peanut root rot, commonly known as rat tail, root rot, etc., is a disease caused by a variety of Fusarium fungus and occurs in peanuts. The disease mainly damages the roots of plants, but can also damage fruit needles and pods. Peanut root rot is a worldwide flower disease, which occurs in all parts of China, especially in the flower production areas of southern China.

In the whole growth period of peanuts can be diseased, causing poor plant growth, rotten seeds, root rot, fruit rot, resulting in the death of the whole plant, generally sporadic occurrence, the disease rate is less than 10%, the yield is reduced by 5-8%, the incidence rate of severe cases is 20-30%, and the yield is reduced by more than 20%. The control of peanut root rot can be carried out using agricultural control and chemical control methods. In agricultural prevention and control, it is necessary to clean the countryside in time, implement crop rotation and intercropping, timely drainage and irrigation, carry out reasonable fertilization, and select high-quality varieties with strong disease resistance.

In terms of chemical control, on the basis of ensuring the quality of seeds, seed coating or seed dressing is adopted; In the early stage of the disease, when the rate of diseased plants (holes) in the field reaches 5%, timely pesticide prevention and control should be carried out. <>

Peanuts are damaged after sowing and before emergence, which can cause rotten seeds and rotten buds. The seedling stage is damaged, the taproot turns brown and rots, the plant is dwarfed, wilts and dies. Damage at the adult stage usually manifests as chronic symptoms, beginning to show temporary wilting, leaf loss of water, greening, yellowing, and drooping petioles.

There are slightly concave long brown lesions on the root neck, the root end is wet rot, the cortex becomes brown and rotten, easy to fall off, the taproot is thick or slender, there are no lateral roots or very few, the shape is like a rat's tail, the vascular bundle changes, the plant gradually dies, and it only takes 2 days from the manifestation of symptoms to death in severe cases. When the soil moisture is high, adventitious roots can grow in the root neck near the ground, and there is a layer of fungus and mildew on the surface of the diseased part. The aboveground part of the diseased plant showed dwarf, poor growth, yellowish leaves, little flowering and fruiting, and most of them were fruits.

The fungus damages the fruit needles and young pods that enter the soil, and the pods are easy to fall off in the soil after the fruit needles are damaged. Bacteria and Pythium co-infect the pods, which can cause the pods to rot. <>

Your seed dressing is not very good, increase the amount of carbendazim, and spray foliar fertilizer will be better, and foliar fertilizer should be better.

It is generally caused by infection with peanut leaf spot, and foliar spraying of difenoconazole. propiconazole, or difenoconazole. Azoxystrobin, or tebuconazole.

carbendazim, or pyraclostrobin. Dai Senlian, or thiazine copper, or spring thunder king copper, or copper hydroxide, etc., the effect is very good. Foliar spraying every 7 to 10 days after the onset of the disease, 2 3 sprays in a row, can control the onset of the disease.

Add potassium dihydrogen phosphate and spray together, the control effect is better.

Spraying high yield and yield increase in peanut seedling stage to early flowering stage**, strengthen seedlings to promote flowering, rooting and strong roots, high resistance to heavy stubble, prevent seedling yellowing, seedling weakness, small leaves, leaf rolling, dead seedlings, rotten roots, and increase flower growth potential. In the peanut flowering and needle stage, spray the second high yield to increase yield**, supplement trace elements, prevent bacterial wilt, root rot, stem rot, leaf spot, rust, etc.

Now the peanut leaves are rotten, so hurry up and take medicine, fertilize and water, so that the water and fertilizer are used and there will be no rotten leaves.

Infected with diseases, peanut root rot may be caused by infectious diseases, and it is necessary to spray pesticides in time**; Improper sowing, using moldy seeds when sowing peanuts or sowing too early will cause peanuts to rot roots; Stubble planting, if planted in the stubble plot will also cause peanuts to rot roots, so before sowing the plot needs to be turned over and sprayed with carbendazim solution for disinfection.

If peanuts have root rot, they may be infected with root rot, seedling blight and other diseases. After the onset of the disease, the fungus will infect the underground part of the seedling, the taproot will turn brown, and the peanut seedling will appear dwarf and blighted, so that it can not carry out photosynthesis normally, and the root system lacks nutrients, and the root rot will occur.

If moldy seeds are used when sowing peanuts, or the sowing time is too early, the soil temperature is low, which slows down the germination rate of peanuts, or if the seeds are too sown and the seeds are left in the soil for a long time, it is easy to make the peanut roots mildew.

If peanuts are planted in stubble plots, it will lead to a large number of bacteria, pests and diseases in the soil, and the pests will be more serious in the continuous cropping fields, Huangchangaochai clay soils, and gravel plots with thin soil layers. Therefore, before sowing peanuts, it is necessary to turn the plot and mix an appropriate amount of well-decomposed organic fertilizer to improve the fertility of the soil.

After the peanut sowing is completed, the weather is unstable, there is a long period of low temperature, rainy weather, seedlings in the case of large soil moisture, easy to affect the growth of plants, easy to appear rotten roots. When maintaining peanuts in the later stage, it is necessary to dig a trench in time to drain the water in the soil before the rainy season comes.

Causes of peanut root rot:

1. Poor seed quality: Peanut seed quality is poor.

2. Sowing too early or too deep sowing too early, low ground temperature, reduced activity of seed enzymes, weakened respiration, slow germination of peanuts, prolonged sowing too deep and soil retention time, reducing seed disease resistance.

3. Heavy stubble is serious, and the soil pathogenic bacteria and pests of peanut heavy stubble accumulate a lot, and the base of diseases and insects is large.

4. Improper use of chemical fertilizers, unrotted manure, chemical posture insecticides, etc., which are in direct contact with seeds or use too much, are easy to cause burning and rotting seeds.

Peanut root rot prevention and control measures:

1. Choose high-quality seeds, whether you buy seeds or keep seeds.

2. Do a good job of seed treatment, dry the seed fruit for 2 to 3 days from one month to half a month before sowing after seed selection, peel the shell, select and grade the grain, and remove the diseased kernel.

3. Increase the application of bacterial fertilizer, use herbicides with caution in field tillage to be fine, ensure that the ground is flat and loose, there is no big stump, and it is best to use some microbial fertilizer to apply with cultivated land in serious plots. When using chemical fertilizer as seed fertilizer, it is necessary to carry out and disturb the seed and separate it to prevent the burning of the seed. Watering should be sufficient and even, the sowing depth should be consistent, about 3 cm is appropriate, and the soil should be tightly covered.

4. Timely post-seedling management After most seeds emerge, if some unseeded holes are found, you can dig to check whether the seeds have deteriorated and rotted or cannot emerge.

<> ferrous sulfate solution is sprayed on the foliage, sprayed 3-4 times in a row, sprayed once every 7 days, and supplemented with iron, which can control peanut yellow leaves; Spraying 1% urea aqueous solution on the foliar surface of peanut plants can prevent and control peanut yellow leaves caused by nitrogen deficiency. 150 grams of ferrous sulfate and 50 grams of zinc sulfate mixed with 60 kg of water can be sprayed on the foliar surface to prevent and control peanut yellow leaves caused by zinc deficiency. In addition, controlling the amount of watering can avoid peanut yellow leaves.

1. What to do with peanut yellow leaves

1. To prevent and control the yellow leaf phenomenon of peanut iron deficiency, the most commonly used is to use ferrous sulfate to spray the foliar surface, the generally available ferrous sulfate solution is sprayed on the foliar surface, sprayed 3-4 times in a row, sprayed once every 5-7 days, and the neutral laundry detergent added to enhance the adhesion of the foliar surface to improve the spraying effect and enhance the absorption function of the foliage.

2. For zinc deficiency and yellowing mixed plots, 150 grams of ferrous sulfate and 50 grams of zinc sulfate can be used per mu, mixed with 60 kg of water, sprayed on the foliage, and 10 grams of chelated zinc can also be supplemented, so that the control effect is better.

3. To prevent and control nitrogen deficiency yellowing, you can apply an appropriate amount of nitrogen fertilizer before watering or rainfall, and the plots where top dressing is inconvenient can be sprayed with about 1% urea aqueous solution on the foliar surface, and after spraying once, the phenomenon of peanut yellow leaves can be effectively controlled.

4. If the peanut is watered too much, it will reduce the permeability of the soil, resulting in insufficient oxygen, the ground temperature plummets, and the roots are basically unable to breathe, thus affecting the nutrient absorption of peanuts. It leads to the loss of nutrients in the soil, or the soil is accumulated due to the lack of timely drainage, resulting in large-scale yellow leaves of peanuts, so it is necessary to pay attention to control the amount of watering, not too much watering, to ensure the normal growth of peanuts.

5. Excessive soil acidity is also one of the causes of peanut yellow leaves, and lime should be used to reduce soil acidity.

6. After the occurrence of peanut pesticide damage, timely spray plant regulators such as Fengqia Duobao plus brassinolide to improve crop nutrition and immunity.

Second, the performance of peanut yellow leaves

1. Nitrogen deficiency in peanuts will cause yellowing and green loss of peanut leaves, and also show that the leaves will become thinner and smaller, and the plants will be short.

2. Zinc deficiency in peanuts is generally manifested as leaf clusters and yellow-white lobular disease.

3. When the iron deficiency of peanut is severe, the leaf veins lose green and then yellow, and the upper new leaves all turn white, brown spots and necrosis appear, and they dry up and fall off.

Peanut yellow leaves may be planted in the soil of peanuts is not suitable for plant growth, need to replace fertile and loose soil to replant peanuts, or may be peanuts in the process of growth received insufficient light, need to supplement peanuts with sufficient light, or may be the maintenance of peanuts to provide unreasonable water and fertilizer, need to provide peanuts with balanced nutrients and nutrient-rich water.

1. Supplemental light

Peanuts are suitable for growing in a sunny environment, if the peanuts absorb insufficient light in the process of growth, there will be yellowing of the leaves, so when maintaining peanuts, it is necessary to provide all-day sunshine for the plants, so that peanuts can photosynthesize normally, and when the light is too strong, it is necessary to shade the peanuts in time.

2. Reasonable fertilization

Peanuts in the process of growth of nutrients demand is larger, peanut fertilizer deficiency will appear leaf yellowing, so in the later maintenance of peanuts need to provide nutrients for the plant reasonably, it is best to use nitrogen fertilizer in the peanut growth period, in the peanut fruiting period to use phosphorus and potassium fertilizer, so that the plant better growth.

3. Reduce moisture

Providing too much water for peanuts during maintenance will lead to water accumulation at the roots of the plant and yellowing of the leaves, so it is also necessary to provide water for the plant correctly when maintaining peanuts, and it is best to provide water for peanuts after the soil is dry and soak all the soil. At the same time, after overwatering, it is necessary to loosen the soil in time to drain excess water.

4. Replace the soil

The soil for planting peanuts is not suitable for plant growth, and there will also be yellowing of leaves, so when maintaining peanuts in the later stage, it is necessary to replace the soil and replant, and it is best to use sandy loam soil with rich organic matter content and good drainage when replacing the soil, so that the plants can grow more vigorously.

Yellow leaf disease.

What's the deal with yellowing peanut leaves? How to prevent it?

1. Reasons for the yellowing of peanut leaves.

1. Lack of nutrients. Iron deficiency yellowing: In general, there is no obvious change in the leaf size of peanut, but the loss of green yellowing is obvious; Nitrogen deficiency yellowing: the old leaves in the lower part of the plant fade green, and generally the leaves become thinner and smaller. Zinc deficiency yellowing: the leaves are clustered and yellow-white lobular disease appears.

2. Soil. The soil is sticky, compacted, and the wheat straw is not completely crushed, and the wheat stubble is not properly treated. It leads to the phenomenon of yellow leaves due to malnutrition of peanuts.

3. Water and fertilizer. Excessive rainfall, overwatering, low oxygen, and excessive soil moisture. Or it is the burning of seedlings and rotten roots caused by excessive fertilization, and the yellow leaves of peanuts are manifested in the aboveground part.

4. Diseases. For example, peanut root rot and white silk disease have symptoms such as poor growth, yellowing of leaves, and in severe cases, lead to the wilting of the whole plant. Insect pests such as grubs and mole crickets are the same, mainly invading the roots of peanuts, resulting in obstruction of nutrient absorption of peanuts and causing malnutrition of yellow leaves.

2. Prevention and control of yellowing of peanut leaves.

1. Soil selection.

When growing peanuts, it is best to use sandy loam soil or humus that is rich in organic matter and well drained. If the soil is acidified, alkalized or salinized, it needs to be treated before planting.

2. Apply plantar fertilizer.

Before planting peanuts, with the preparation of the land to apply foot fertilizer, and it is best to use the way of ridge planting, when sowing, the seeds and fertilizer to keep a distance of about 7 cm together into the soil. You can choose a balanced compound fertilizer for seed fertilizer, 35-40 kg per mu.

3. Element supplementation.

There are two main ways to supplement trace elements such as iron, the first is to fertilize before sowing, and the second is to carry out foliar spraying after the yellowing of peanut leaves. Farmers can choose according to the condition of the soil.

4. Do a good job of drainage.

In the case of stagnant water in the field, timely drainage should be carried out to reduce the humidity in the field, and at the same time, brassinin and soil chef polypotassium dihydrogen phosphate should be sprayed to promote the normal growth of peanuts.

5. Pest control.

For peanut underground pests, it is generally prevented by pre-sowing seed dressing, and in the middle and late stages, if there are underground pests, chlorpyrifos and phosphine are used for control. For flower diseases, thiofuramide, tebuconazole, azoxystrobin, difenoconazole and other agents can be sprayed for prevention and control.

Peanut yellow leaves are caused by lack of nutrients, herbicide damage, drought or waterlogging, root-knot nematode disease, insufficient fertilizer can be applied urea in time, if the pesticide damage is not serious, you can spray foliar fertilizer or brassicin to alleviate, timely irrigation and watering during drought, when waterlogging, do a good job of drainage, for root-knot nematode disease, can be used to kill line phosphorus, Mixian and kill the borer to prevent and control.

Peanut yellow leaf causes.

1. Lack of nutrients. When peanuts are malnourished, there may be yellowing of leaves, such as nitrogen deficiency, when applying base fertilizer, the dosage is not enough, which not only leads to yellowing of peanut leaves, but also appears symptoms such as plant dwarfing and slow growth, and in severe cases, yellowed leaves fall off directly.

2. Herbicide damage:When spraying peanut herbicides this season, due to improper operation, resulting in yellowing of leaves, in addition, the last crop is sprayed with herbicides after the year, in the case of excessive benzensulfuron, the residual period is too long, and the peanuts are planted in the next stubble, it is easy to have pesticide damage.

3. Drought or waterloggingPeanuts like a moist environment, usually watering according to the dryness and humidity of the soil, if the field is too dry or there is stagnant water, it may cause peanuts to appear yellowing symptoms.

4. Root-knot nematode disease:The common disease of peanut is root-knot nematode disease, which basically occurs in peanut planting areas, and root-knot nematode disease will also cause yellow leaves in peanuts, which has a greater impact on yield.

Treatment method for yellowing peanut leaves.

The yellowing of peanut leaves is caused by a lack of nutrients, which can be remedied by topdressing urea, taking care not to overdose, according to the severity of the pesticide damage. If it is not very serious, it can be alleviated by spraying foliar fertilizer or brassin, if the damage is particularly serious, then there is no way.

For the yellowing of leaves caused by drought or waterlogging, it can be treated according to the situation, irrigation and watering should be carried out in time during drought, and drainage should be done when waterlogging occurs. Then spray some foliar fertilizer to promote recovery, for root-knot nematode disease, you can use line-killing phosphorus, mixian and borer dan to prevent it, and the best measure is to prevent it in advance.

Peanut yellow leaf control.

When planting peanuts, you can apply base fertilizer to improve the fertility of the soil, and apply thin fertilizer frequently during the growth period to meet the needs of leaf growth, which can reduce the appearance of yellow leaves. In addition, it is best to keep the substrate moist by paying attention to drainage during the rainy season and watering frequently when the soil is dry.