What are the prevention and control methods of lettuce stem rot? Stem rot

It should be a disease in the soil, and it should be paid attention to for a long time, and the pathogens in the soil of similar plants are not effectively protected, so the bacterial breeding is more serious, and the disinfection of the soil is also done.

Lettuce stem rot mainly starts from the petiole near the base of the stem, and amorphous brown necrotic spots appear, which later extend to the entire petiole and ooze dark brown sap, causing the leaves to rot.

The temperature is 27 30, and it is easy to get sick under rainy conditions, continuous cropping fields, low-lying waterlogging, stuffy, humidity, and severe disease. Excessive temperature, high soil moisture, water accumulation in vegetable fields, too dense planting, and excessive application of nitrogen fertilizer will cause serious diseases.

Prevention and control methods: 1. Thoroughly clear the garden and dry the soil before planting. Combined with land preparation, use 40% pentachloronitrobenzene wettable powder and 40% Fumei double wettable powder per square meter according to 1:

1. Mix 5-8 grams of agent evenly, mix well with an appropriate amount of fine soil and sprinkle it on the furrow surface, and then mix it with a hoe and surface soil for disinfection.

2. Crop rotation with rice; Raise the furrow surface, do not flood irrigation; Moderate dense planting to reduce field humidity; Increase the application of phosphorus and potassium fertilizer, and spray the application of potassium dihydrogen phosphate in fertile leaves.

3. If the diseased plant is found in the field, immediately pull out and sprinkle a small amount of medicinal soil for disinfection.

4. Pesticide prevention and control: once the seedbed is found to be diseased, it should be pulled out in time, and then sprayed or watered with pesticide to control the spread of the disease. Pay attention to spraying with pesticides or irrigating the roots, sprinkle some plant ash and fine dry soil to reduce humidity and keep warm.

The green bamboo shoots were softly rotted by the pathogenic bacterium carrot Carey.

After the soft rot of Erwinia carrot is infiltrated, the disease generally develops gradually during the exploratory period of taking fleshy stems. Different green shoot plants after the onset of the disease are likely to reflect two different diseases. A kind of disease from the outer leaves gradually expands inward, the first at the intersection of the tip of the outer leaf stem and the underground stem, gradually is water-like, the outer leaf wilts in the afternoon on a sunny day, and can also be repaired in the morning, evening or rainy day.

After a few days, the outer leaves of the green shoots will be killed and will stick to the road surface, and there will be no repair. At this time, the outer leaves of the entire green bamboo shoot have all slumped on the road, revealing the young heart leaves of the green bamboo shoots. The leaf stems, stem tips, and heart marrow organs of green bamboo shoots have turned brown and rotted, and are filled with milky white and tan thick liquid, which can smell rancid.

Another symptom is that, as the questioner often said, the susceptible plants of green bamboo shoots first rot their heart leaves and expand from the inside out. The pathogen invades from the apex of the lettuce leaves, causing the onset of green bamboo shoots. In the early stage of the disease, the growth and development of green bamboo shoot plants is normal, and <>

The heart leaves slowly rot outward, and the sickened plants are prone to collapse due to the foul-smelling yellowish thick liquid. It is a fungus and insect pest, caused by Carrot soft rot Euclonibacterium. 【Condition】Damage to the leaf surface, leaf stem, at first in the tip of the transparent color invasion spots, slowly expand and then turn gray, the water of the body is rotten, the old body lacks water and shrinks.

At the beginning of the disease, the leaves can recover at night or on rainy days, and the leaf stems can not stand up again after the disease is aggravated, and the leaf surface collapses.

The impregnation develops from the tip of the leaf stem to the shrinking stem, which can cause the root pith to rot and overflow the foul-smelling earthy yellow viscous crystalline. After the pathogen enters the bundle tube from the parenchyma tissue, it can develop along the petiole to cause the whole tree to rot to prevent re-stubble, and dig the drainage pipes and canalsImproving irrigation standards. Prevent the use of organic fertilizers without manure and immediately eliminate the residue of diseased plants in the field.

In the early stage of the disease, drugs can be sprayed for prevention, such as new mouth phytomycin, agricultural resistance 120, and agricultural machineryChloramphenicol, allicin, hydrate, copper pineate and other pesticide fungicides. Spray every 7 10 days, 2 3 times in a row.

Rotten lettuce hearts can be caused by overwatering, or it can be the cause of pests and diseases. You can use the right amount of light, spray pesticides, pinch branches, prune from the roots, apply some fertilizer, catch pests, all of which can prevent the heart of lettuce from rotting and give lettuce a good harvest.

Soft rot , spraying pesticides, choosing the right varieties for planting, paying attention to the treatment of the soil, paying attention to the removal of weeds.

It may be sclerotinia sclerotiorum or lettuce mosaic disease; Proper spraying of pesticides, proper fertilization, keeping the soil moist and increasing air circulation.

Soft rot is a bacterial disease, and the types of bacteria that cause soft rot in different crops may be different, among which the pathogen that causes soft rot in lettuce is Euclideus carrot subsp. carrot. The occurrence of soft rot requires high temperature and humidity conditions, and only in high temperature and humidity, lettuce soft rot is mainly harmed by leaves, stems and tubers. Disease-infested tubers will rot partially or completely or wet-rot in a short period of time with a foul smell.

When dividing seedlings and planting, the diseased seedlings are eliminated, and the seedlings are planted reasonably and densely when they grow straight leaves. Do not apply nitrogen fertilizer partially, and increase phosphorus fertilizer and potassium fertilizer when topdressing in the later stage. Diligent cultivation, watering, can not flood irrigation, pay attention to the elimination of stagnant water after rain.

For the disease of lettuce, we farmers should adhere to the plant protection policy of "prevention first, comprehensive prevention and control", adapt measures to local and time conditions, and comprehensively use agricultural, biological, physical and chemical prevention and control measures to effectively suppress the disease. In terms of prevention and control, the density of lettuce can be sparse in moderation, which is the best measure to create ventilation conditions, and it is also an effective measure for the prevention and control of diseases of many crops grown in vegetable greenhouses.

Soft rot bacteria usually overwinter on diseased carcasses or in soil, and when the environmental conditions are suitable, they will invade the lettuce from the wounds, cracks on the surface of the lettuce and the water holes at the edge of the leaves with irrigation water and improper agricultural operations, and then grow and multiply to a certain extent, and the lettuce soft rot will develop the disease. In the analysis of specific topics, I don't know what kind of greenhouse you choose to plant lettuce? Do you have cooling measures in place for your greenhouse?

There is also the temperature of your greenhouse lettuce planting in what degree is generally the situation, whether you know the temperature range suitable for the growth of lettuce.

We choose the land with good soil quality and good air permeability as the planting base, build a greenhouse on the top, and then plough the land after building the greenhouse. We have to water the land that has been cultivated, and for the first time, we must water it deeply, so that the soil can drink enough water, and the seeds will sprout quickly.

I think lettuce soft rot is a common disease, if we want to better control this disease, we should adopt some effective measures in advance, spray some drugs to prevent and control the disease on their surface.

Thorough clearing of the garden, soil turning or crop rotation with rice before planting can reduce the source of fungal bacteria. Raise and level the furrow surface to facilitate irrigation and drainage, and do not flood with water. Moderate dense planting should maintain good permeability in the field, reduce the field humidity, and appropriately increase phosphorus and potassium fertilizers to enhance the mechanical resistance of the plant epidermis.

Pay attention to cleaning the ditch and draining the stain in time after rain or irrigation. Combined with disease prevention, foliar sprays such as potassium dihydrogen phosphate and boron fertilizer were applied to improve plant stress resistance. Pharmaceutical prevention and control:

Choose 1000 times of dycenum water, or 4000 times of 72% agricultural streptopenicillin or neophytomycin, or 500 times of 47% killable powder, or 800 times of 47% Garinon powder or 600 times of DTM (chlorothalon) powder, once every 5 7 days, 3 4 times in a row.

Pesticides. Because my lettuce has not been soft rot since being sprayed with pesticides, it should be treated with pesticides.

The first is to plant reasonably densely, and secondly, it can be prevented and controlled with drugs.

The soil should be made more dry and drained regularly to prevent the disease.

Lettuce anthracnose is easy to appear in a cool and humid environment, it is recommended to use bromidionile, difenoconazole propiconazole, prochlorazole manganese salt, prochloraz, dicyananthraquinone, strict quarantine when planting, to prevent diseased seeds from entering, disinfection of seeds, application of fermented organic fertilizer, drainage measures in the rainy season, and timely removal of diseased leaves.

Causes of lettuce anthracnose.

The fungus can be spread over long distances with the seed transportation, mainly by the bacterial soil and the farmhouse fertilizer mixed with the fungus in the field, the pathogen overwinters on the diseased residue or the small sclerotia left in the soil, and produces doppelganger spores when the conditions are suitable, spreads by rainwater or irrigation water, invades from the stomata or directly penetrates the leaf epidermis, and the weather is cool and humid and easy to get sick.

Lettuce anthrax symptomatic manifestations.

The main symptom of lettuce anthracnose is that at first it produces small light yellow lesions on the peripheral leaves, which are water-stained, and then turn reddish-brown, and the fissures lesions overflow with pink myxospores, resulting in a large area of necrosis of the leaves, and the pitted spots on the middle ribs of the leaves, resulting in leaf rot.

Lettuce anthrax**.

Lettuce anthracnose is recommended to use bromonitrile, difenoconazole, propiconazole, prochloraz manganese salt, prochloraz, dicyanthracene source without quinone, pay attention to prochloraz manganese salt, propiconazole, prochloraz excessive use will inhibit growth, to control the dosage.

Lettuce anthrax medication.

Lettuce anthracnose is most effective with 3000 times of 40% etherstrobin dry suspension or 500 times of 70% zebin dry suspension.

Lettuce anthrax prevention and control methods.

Lettuce planting should be strictly quarantined, to prevent diseased seeds from entering, to disinfect the seeds, apply fermented organic fertilizer, the soil should not be too wet during the growth period, do a good job of drainage measures, diseased leaves should be removed in time, spray 40% etherstrobin dry suspension 3000 times or 70% zebsen dry suspension 500 times liquid at the beginning of the disease.