What are the common pests and diseases of roses?

But the farmers who have planted a lot of roses know that planting roses in a large area is prone to pests and diseases, which seriously affects the yield and quality of roses, and directly damages the interests of flower farmers.

The main diseases and insects produced by <> rose flowers are anthracnose, black spot, powdery mildew, leaf spot and so on. Among them, the harm of anthrax and dust disease is more serious. Anthrax.

Symptoms: When the rose flower has anthracnose, it usually turns brown from the leaf margin, and the chlorophyll gradually disappears, and then forms semicircular spots. The spots turn from brown to black in the later stages.

After that, the pathogenic spores spend the winter on the leaves, and when the real leaves are diseased and bloom in the spring, when the conditions are right, they infest the leaves of the roses again. Anthrax occurs frequently and can be prevented along with black spot and leaf spot.

The prevention method is in late autumn and early winter, when it falls from the rose petals, be sure to clean it in time and in the warm rose garden, the diseased fallen leaves burn and strengthen some cripples, you can see the sick maintenance, proper maintenance, prevent the branches from being too dense It is a paradise where the virus does not take root in direct sunlight. According to the need, it can spray 500 times of 20% gentian suspension, 600 times of 78% wettable powder, 600 times of 75% wettable powder, 1000 times of 50% wettable powder, and 500 times of 25% wettable powder.

Mild disease. Symptoms: Powdery disease has developed on the leaves, petioles, and buds of roses.

In the case of symptoms, these areas will irregularly produce mold in the form of white powder. In the case of adult leaves, they turn brown from the edge of the leaf tip and fall off, and if they are young leaves or flower buds, they may dry up or powdery powder, and in severe cases, they may even wither and die. Hay fever is prone to occur from late autumn to early spring, during periods of large temperature difference between day and night and high humidity.

Prevention and control methods: If roses appear, they can be controlled with regular sprays, 600 times of nitrile methanol, 800 times chlorothalonil and other agents that should be used immediately. Spraying every 7-10 days, sometimes watering the leaves, can inhibit the onset of powdery disease.

If you find a diseased branch, cut it off as soon as possible to reduce the chance of respread.

In such a situation, we must spray pesticides in time, and then we should also prescribe the right medicine, we also need to spray some insecticides and fungicides, to keep the light sufficient, we also need to pay attention to the temperature control, which should be controlled at about 18, and prune the branches and leaves in time to avoid rotting.

Be sure to choose the right insecticide or herbicide according to the type of pests and diseases, pay attention to the dosage of spraying, dilute pesticides and water in advance, and then ensure that fertilizer and water are sufficient.

Common pests and diseases of roses include powdery mildew, which can be carried out with powdery rust rather than wet powder**; For downy mildew, use water to dilute about 73% of the dew**; For blight disease, carbendazim wettable powder diluted with water by about 25% is used; Aphids** should be prevented with dimethoate; Spider mites use 600 times more mites to die**.

Disease control1. Powdery mildew

Many people ask how to carry out the pest control of roses, the main disease of roses is powdery mildew, at the onset of the plant's young leaves are raised, and the color of the raised place is white-pink, and the back of the entire leaf surface will be covered with a layer of mold when it is serious, and it is necessary to use 25% of the powder rust rather wet powder or potassium permanganate solution every 7 10 days to spray the onset of the leaf surface until it is cured.

2. Downy mildew

When roses have downy mildew, the leaf color will turn brownish-black, and wither and then fall off, there will be spots on the branches and petals of roses that affect the appearance, in the case of this symptom, you need to spray 72% gram dew for **, in **, you can add an appropriate amount of nitrogen-containing fertilizer for nutrient replenishment, to avoid growth affected.

3. Blight disease

Blight disease is a common disease of roses, which will cause the leaves of the branches to fall off to form bald branches when the disease occurs, and in severe cases, it will cause the wilting and death of the branches.

Pest control1. Aphids

When roses are harmed by aphids, it will cause the color of the leaves of the plant to fade and curl and become hard and brittle, which will affect the absorption of nutrients and cause the growth to slow down.

2. Red spider

When roses are infested by red spiders, red spiders will feed on the sap in the leaves of the plant, resulting in too little chlorophyll in the leaves of the plant, which affects the photosynthesis of the plant and affects the growth of the plant, so it is necessary to use 600 times dilution of mite instant dead water or dicofol emulsifiable concentrate 2000 times diluted with water for spraying** until it is cured.

Common pests and diseases of roses include powdery mildew, which can be carried out with powdery rust rather than wet powder**; For downy mildew, use water to dilute about 73% of the dew**; For blight disease, carbendazim wettable powder diluted with water by about 25% is used; Aphids** should be prevented with dimethoate; Spider mites use 600 times more mites to die**.

1. Powdery mildew

Many people ask how to carry out the pest control of roses, the main disease of roses is powdery mildew, at the onset of the disease, the young leaves of the plant are raised, and the color of the raised place is white-pink, and in severe cases, the back of the entire leaf surface will be covered with a layer of mold, and it is necessary to use 25% powder rust rather wet powder or potassium permanganate solution every 7 10 days to spray the leaf surface of the disease until it is cured.

2. Downy mildew

When the rose has downy mildew, the leaf color will change to Zhitong brown black, and wither and then fall off, the branches and petals of the rose will appear spots to affect the appearance, in the appearance of this symptom need to spray 72% gram dew for **, in ** can add an appropriate amount of nitrogen-containing fertilizer for nutrient supply, to avoid growth affected.

3. Blight disease

Blight disease is a common disease of roses, which will cause the leaves of the branches to fall off to form bald branches when the disease occurs, and in severe cases, it will cause the wilting and death of the branches.

1. Aphids

When roses are harmed by aphids, it will cause the color of the leaves of the plant to fade and curl and become hard and brittle, which will affect the absorption of nutrients and cause the growth to slow down.

2. Red spider

When roses are infested by red spider insects, red spiders will feed on the sap in the leaves of the plant, resulting in too little chlorophyll in the leaves of the plant, and the growth of the orange will be affected by the photosynthesis of the plant, and it is necessary to use 600 times diluted with water or dicofol emulsifiable concentrate 2000 times diluted with water for spraying** until it is cured.

Diseases of roses include powdery mildew and downy mildew, etc., after the disease appears, the diseased leaves should be cut off in time, and then sprayed with special fungicidal drugs**. Its common insect pests are aphids and red spiders, after the occurrence of insect infestations, it is necessary to use insecticides in a timely manner**, and the usual maintenance of roses should be well managed by ventilation, so that the plants can grow robustly.

1. Powdery mildew

The disease of roses has powdery mildew, the leaves of the plant will be convex when the disease occurs, and there is white powder, and finally the leaves will be curled, and the back of the whole leaf is covered with a layer of gray-white mold, after the appearance of this disease, the diseased leaves should be cut off in time, and then sprayed with mycloconazole 600 times, chlorothalonil 800 times and other agents**.

2. Downy mildew

Downy mildew is also a common disease of roses, the leaves of the plant will turn purple to brown-black at the onset of the disease, and there will be small spots, and finally gradually wither and fall off, generally in an unventilated environment is most prone to this disease, after the appearance of this disease can be sprayed with 72% gram dew **, usually to avoid it in a humid and hot environment.

3. Aphids

In the process of growth and development, roses are susceptible to aphids, after the occurrence of this insect pest, it will be observed that the stems and leaves of the plant are eaten by pests, at this time, you can use aphid lice net spraying**, you can also use dichlorvos fumigation, if you want to avoid it from this disease, you need to spray with insecticides every day to prevent.

4. Red spider

When the high temperature in summer, roses are prone to red spider insect pests, it will absorb the chlorophyll in the leaves, so that the roses can not carry out photosynthesis, so that the plant will grow badly, when the disease occurs, we can use the mite to die 600 times liquid spray, or with sharp mite net 1000 1500 times liquid spray for control.

Common diseases and insect pests of roses include residual rust, black mold, white and powdery powder, etc., and the control methods are as follows:

1. When pruning the plant, check the root stubble pith and find that there is a cavity, you can drop 1 to 2 drops of 80% DDVP emulsifiable concentrate, and then seal it with mud;

2. If the young shoots are infringed, they can be cut off and destroyed, and the rose noctuidae harm the leaves with larvae, and bite the flower buds and flowers at the same time, which can be controlled by spraying 90% crystal trichlorfon 1000 to 1500 times, or 50% pine mol and 1000 times liquid spray;

3. Red spider damage the front and back of the leaves, causing the leaves to dry and fall off, in the early stage of the disease, you can use 20% dicofol EC to destroy 1000 to 1500 times of the liquid, or 23% of the dicofol wettable powder 800 to 1000 times of liquid spray, the front and back of the leaves need to be sprayed, sprayed once every 15 days, generally sprayed 1 to 2 times.