What are the main diseases of spinach?

What are some common pests and diseases of spinach? How to prevent it? The following mainly talks about the comprehensive control measures for common spinach diseases from the three main diseases of spinach, I hope it will help you who have planted spinach!

1. Spinach white spot disease

Harmful symptoms: Spinach white spot disease is mainly manifested on leaves. The lower leaves are the first to develop into white spots with round to near-round lesions, yellowish-white in the middle and brown to purple-brown on the outer edges, which gradually develop into white spots after expansion.

When the humidity is high, gray hairs can be seen on some lesions, and when the dryness and wetting change are intense, the middle of the lesions is easy to rupture. The spinach white spot fungus overwinters in the soil with the mycelium and the diseased residues, and spreads through wind and rain in the next spring. It is easy to develop disease under weak growth potential, warm and humid conditions, and severe disease is caused by low-lying terrain, nest wind, and poor management.

Control methods: Choose a flat terrain and a ventilated plot with sufficient organic fertilizer to plant spinach, properly water, fine management, and improve plant disease resistance. After harvesting, the diseased residues should be removed in time, and buried or burned in a concentrated manner to reduce the source of disease.

At the initial stage of the disease, spray 400 500 times of 30% green debao suspension, or 1 Bordeaux solution, 75% chlorothalonil wettable powder 700 times.

2. Spinach wilt

Harmful symptoms: Spinach wilt generally occurs more seriously in the adult plant stage. It is manifested that the old leaves become dark and lose their luster, the mesophyll gradually yellows, gradually expands upward, and the roots turn brown and die when they develop downward.

Plants with early onset are significantly dwarfed. When the weather is dry and the temperature is high, the diseased plants quickly turn yellow. Under moist and low temperatures, diseased plants can continue to survive for a period of time, sometimes growing new lateral roots.

But when it hits high temperatures, it dies quickly.

Control methods: Implement 3 5 year rotation with onion and grass crops to avoid continuous cropping. Compost or well-decomposed organic fertilizer made by Japanese enzyme bacteria was applied, and formula fertilization technology was used to improve the disease resistance of the host.

The use of high furrow or ridge cultivation, timely drainage after rain, it is strictly forbidden to flood irrigation. If the central disease plant is found to be removed in time, the disease hole and the surrounding area should be sprayed with 1500 times of 50% phenomyl wettable powder, 500 times of 40% polysulfur suspension, or 300 400 times of 10% Zhizhiling aqueous agent, and sprayed once every half a month, 2 3 times in a row.

3. Spinach downy mildew

Symptoms: Spinach downy mildew is the most common disease in spinach and is caused by a fungus called spinach downy mildew. The symptoms of field hazards are as follows:

It mainly harms the front of the leaves, and the lesions are pale yellow; After the lesions enlarge, they are connected to each other into patches, and later turn brown and die. A grayish-purple mold layer is produced on the lesions on the back of the leaves. The disease progresses from the outer leaves to the inner leaves, spreading upwards from the lower part of the plant.

In drought, the diseased leaves wither yellow, rot more when the humidity is high, and the whole leaves of the serious plant turn yellow and die.

Spinach downy mildew. Spinach downy mildew is a fungal disease caused by an oomycete. The pathogen overwinters on diseased leaves and seeds with hyphae or in diseased leaves with oospores.

The mold layer on the back of the lesion is the sporangia and sporangia of the fungus, which are spread by the air stream and produce new lesions. Condensation and high humidity are important conditions for pathogen infestation. Spinach downy mildew mainly damages the leaves.

The disease is severe under the conditions of high planting density, poor field ventilation, low-lying stagnant water, low temperature and high humidity.

2. Spinach white spot disease. Spinach white spot disease is a fungal disease, the fungus overwinters in the soil with the mycelium with the diseased residues, and the fungus spreads by wind and rain in the next spring. Weak growth, warm and humid conditions are susceptible to disease.

3. Spinach gray mold. It is mainly harmful to leaves. Initially, light brown irregularly shaped spots, which later expand into large light brown wettifying spots, and disease on the dorsal leaves of the leaves.

1, spinach downy mildew spinach downy mildew, the pathogen is spinach downy mildew, belonging to the subphylum Flagellates fungi, the sporangia stem extends from the stomata, the terminal peduncle is short and pointed, colorless, the spindle is not septated, the sporangia are ovate, apical, no milky process, translucent, unicell, oospore spherical, with a thick membrane, yellow-brown 2, the pathogen of spinach gray mold is Botrytis cinerea, which belongs to the subphylum Semi-Knowitives fungi, the pathogen mainly overwinters in the soil or with hyphae and conidia on the diseased residue, and germinates when the conditions are suitable in the spring of the second year, Conidia are produced, which are spread and infected by air currents and rainwater.

1. Spinach downy mildew is a fungal disease caused by an oomycete. 2. Spinach white spot disease is mainly manifested in the upper and lower leaves of the leaves. 3. Spinach gray mold produces a gray mold layer on the disease spots on the back of the leaves.

Downy mildew, the key to damage leaves. The lesions extend from the underside of the plant upwards. The lesions are light yellow at first, and after the increase, they are irregular, the edges are not obvious, and the gray-white mold layer is caused on the lesions on the back of the leaves.

When the lesions are more severe, the lesions are connected to each other, and the lesions become tan in the middle and late stages. When the humidity is high, it turns brown and rots, and in more serious cases, the whole leaf turns yellow and wilts.

Prevention and control methods: In the early stage of the disease, azine bacteria mancozeb, oxone and cyanide urea, frost and ethylenephosphine aluminum, propylene zinc, methyl frost mancozeb and so on can be selected. Spray with water and spray once every 7-10 days depending on the condition.

When the disease is extensive, you can choose downy mildew hydrochloride, fluopyramide, pyraclostrobin, downy mildewcarb acetphosphine phosphate, enoylmorpholine mancozeb and other water sprays, depending on the condition interval of 5-7 days.

Virus disease, which is contracted at the seedling stage, mainly appears as a bright vein or yellow-green pattern on the heart leaves, and then becomes a light green and dense two-color flower and leaf shape. Diseases are mainly manifested in the flowering leaves or heart leaves contraction, yellow leaves withering and falling off in advance or plants curling into a spherical shape. Prevention and control methods:

From the onset of the disease to the early stage of the disease, you can choose nebulizers such as ningnanmycin, pyripeptinomycin, morpholinoguanidine hydrochloride and copper acetate, and spray them once every 5-7 days depending on the condition.

Downy mildew, when the disease is severe, the plant is set out, and the roots are carefully observed, which shows that the fleshy roots are shrunk and deformed, and there are many nodular-like root knots. The upper part of the ground shows poor growth and development, short, green loss, wilting, as if lack of liquid fertilizer or withering disease, and the plant wilts when it is more serious. Prevention and control methods:

Ciliates are produced during the growth and development of broccoli, and the roots can be irrigated with avermectin and other methods, and the cultivation technique can be improved.

Stem blight, in the early stage of disease, it causes fusiform to irregularly shaped dark gray stripes on the stem, the edges of the lesions are dark brown, and the middle and late lesions often cause gray-black smaller. When the disease is more severe, the lesion surrounds the stem for a week, causing the diseased part to wither. Prevention and control methods:

In the early stage of the disease, azoxystrobin, basic copper sulfate, cuprous oxide, quinoxethox, etc. can be sprayed with water, and sprayed once every 7-10 days depending on the condition.

Spinach downy mildew, spinach white spot, spinach gray mold. Fungal diseases, beet leaf moths, these are relatively common diseases. This can be done with some medications or through pesticides.

Including gray mold, aphids, virus diseases, cabbage worms, wilt, it is necessary to use chemical agents in time to ensure the air permeability of the soil.

White spot, downy mildew, wilt, noctuida, cataplexy, must be sprayed in time, and the agent should also pay attention to the law of growth, and kill the bacteria in the soil in time.

Spinach insect pests mainly include aphids, leaf miners, cabbage worms, diamondback moths, noctuidae pests, etc.

1) Aphids. Under the condition of facility cultivation, use 30 cm 20 cm yellow board, according to the density of 30 40 pieces per 667 meters, hang 10 15 cm above the top of the plant, and the field can also repel aphids, or can be controlled with 10% imidacloprid wettable powder 2000 times.

2) Leaf miner flies.

It can be controlled with avermectin EC 2000 2500 times or Aifudin EC 3000 times or insect mite EC 3000 times.

3) Pests such as cabbage worms, diamondback moths, and leaf moths.

It can be controlled with 40% green cabbage emulsifiable concentrate 1000 1500 times or pyrethroid pesticides.

The pesticides prohibited in the production of pollution-free spinach are: methamidophos, methyl parathion, parathion, monocrotophos, phosphine, methyl isosulfon, tert-butylthion, methylthiocyclophos, phosphine, endogenous phosphorus, carbofuran, aldicarb, methropsis, thiocyclophos, fly poison bowl, dithionphos, chlorazophos, benzophos, hexahexane.

6. DDT, toxaphene, dibromochloropropane, amidine, dibromoethane, herbicide, aldrin, dieldrin, mercury preparations, arsenic, lead, dichlorbis, fluoroacetamide, glycofluoride, rat poison, sodium fluoroacetate.

Spinach planting selection of disease-resistant varieties, found that the diseased plant in time to pull out, concentrated burning, scientific watering and fertilization, rainy season drainage measures, appropriate amount of phosphorus, potassium fertilizer, promote the growth of the plant robust, aphids with dimethoate spray, leaf miner fly with phosphine milk hand digging oil, trichlorfon powder spray, downy mildew with redomir, chlorothalonil spray, anthrax with a potato Xunji tobuzin, carbendazim spray control.

A common disease in spinach cultivation.

1. Spinach downy mildew:Harm the growth of leaves, the leaves just appear light yellow irregular small spots, and then the lesions are connected to each other, if the situation is serious, the leaves are yellow, the diseased leaves rot in the rainy season, and there is a gray-purple mold layer on the back of the diseased leaves.

2. Spinach white spot disease. Harm the growth of leaves, the lower leaves are the first to start the disease, the edge of the lesion is obvious, if the air humidity is large, the hair will grow on it, it is easy to develop the disease under warm and humid conditions, low-lying terrain, poor ventilation, poor management, and serious disease.

3. Spinach wilt:Spinach often appears wilt at the stage of adult plants, the old leaves darken and lose their luster, the mesophyll turns yellow, the roots gradually turn brown and die, high temperature and humidity are conducive to the disease, the soil temperature is about 30 degrees, the soil is moist, the fertilizer is not fully decomposed, and the underground pests and nematodes are prone to disease.

4. Spinach anthracnose:The main celery should harm the growth of leaves and stems, and the leaves appear pale yellow stains, and then gradually expand into gray-brown lesions, with small black spots, and the disease is serious under the conditions of rain, low-lying terrain, poor drainage, poor ventilation and high humidity.

Cultivated spinach is the main pest.

The main insect pest of spinach is leaf miner, which will eat the mesophyll, leaving only the epidermis and forming a wide tunnel, which makes spinach lose its commodity value and suffer serious losses.

Spinach pest control.

Select disease-resistant varieties, find that the diseased plants are pulled out in time, burned in a centralized manner, scientifically watered and fertilized, do a good job of drainage measures in the rainy season, apply phosphorus and potassium fertilizers in an appropriate amount to promote the growth of plants, aphids with dimethoate, anti-aphid spray, leaf miner flies with octathion emulsifiable concentrate, trichlorfon powder spray, downy mildew with redomir, chlorothalonil spray, anthrax with methyl tobuzin, carbendazim spray control.

The leaves of spinach undergo a certain color change, because the internal structure of spinach changes dramatically when such a disease occurs.

1. Mosaic type. Many yellow spots appear on the leaves of the diseased plants, which gradually develop into irregular dark green and light green flowering leaves. The edge of the leaf is rolled downward, and the diseased plant is not significantly dwarfed.

2. Dwarf type. In addition to the symptoms of mosaic leaves, the leaves of the diseased plants also became narrow, shrunken and had nodulous protrusions, the heart leaves were curled, and the plants were severely dwarfed. 、

That is, the leaves will wither, and they will die in large areas, and they will only bloom and not bear fruit. This is the symptom of poisoning.

Many yellow spots appear on the leaves, which gradually develop into irregular dark green and light green flowering leaves, the leaf edges are rolled downward, the diseased leaves are also narrowed, shrunken and have nodulous protrusions, the heart leaves are curled, and the plant is seriously dwarfed.