Content
Petunia is a favorite of many gardeners, as it is distinguished by its lush flowering throughout the season. But in order to achieve maximum decorativeness and preserve it, it is necessary not only to provide full care, but also to protect the plant from negative factors. To do this, it is necessary to study the main diseases and pests of petunias from the photo in order to be able to recognize the warning signs at the initial stage of the lesion. Only timely measures will help restore a healthy look to the plant.
Petunia, with proper care, blooms continuously
Diseases of petunia flowers
This culture has a high natural immunity. But since the growing conditions do not always meet the requirements of the petunia, this reduces its resistance. Therefore, the plant can be affected by fungal diseases, which is especially dangerous at the stage of growing seedlings. Therefore, you need to familiarize yourself with what problems a gardener may face when growing it. Knowing the common diseases of petunia seedlings (photo below), and having studied their methods of treatment, you can provide timely assistance to a sick plant.
Blackleg
This disease manifests itself at an early stage in the development of seedlings, when they are not yet able to resist infection. The development of blackleg is caused by several types of soil fungi. The provoking factor of the disease is an increased level of acidity, high humidity and a temperature of more than +25 degrees. When these conditions are combined, sporulation in the substrate is activated.
A characteristic sign of the disease is a dark constriction on the stem of the seedling at the base at the initial stage of development. 2-3 days after its appearance, the petunia shoot in this place becomes thinner, which disrupts metabolic processes in the tissues. In the future, the stem softens and breaks. This leads to the death of plants.
In the presence of favorable conditions, the fungus continues to spread further in the substrate, covering more and more areas. In the absence of adequate measures, it will not be possible to save petunia seedlings. The causative agents of the disease persist in the soil and organic debris, so it is important, when affected seedlings appear, to remove them along with a part of the substrate adjacent to the roots.
To avoid disease of the roots of petunia seedlings, that is, black leg, experienced flower growers recommend using peat tablets for growing seedlings. The soil in them has already been treated with fungicides, which excludes the likelihood of the development of pathology.
Blackleg can destroy all crops in 3 days
Chlorosis
The disease develops when there is a lack of iron in the soil. Chlorosis in petunia can be recognized by light leaf plates, on which dark green veins are clearly visible. Subsequently, the color of the flowers changes, it lacks a bright pigment. Against the background of a lack of iron, the development of the bush stops, and the general appearance of the plant becomes dejected.
Restoration of the decorative effect of a bush with chlorosis takes a long time.
Gray rot
This disease affects young and adult petunia seedlings equally. The causative agent of the disease enters the plant tissue through microcracks in the roots and shoots.
The main provoking factors of the pathological process:
- high humidity more than 80% of soil and air;
- temperature within +14 degrees and below;
- excess nitrogen fertilizers in the soil;
- lack of sunlight.
The disease can be identified by gray-brown spots on the leaves, which initially appear at the base of the shoots. Subsequently, they increase in size and become overgrown with a fluffy bloom of gray.
Petunia with gray rot without treatment dies after 3 days
Powdery mildew
Already by the name of this disease, it can determine its characteristic feature. It is manifested by a thick white bloom, which can initially be found on the leaves, and then on petunia flowers. The disease disrupts the process of photosynthesis, which interferes with metabolism. As a result, the leaves of the plant are deformed and bent upward, and then completely wither.
The disease develops with a combination of such factors:
- sharp temperature drops;
- high humidity;
- irregular watering;
- thickening of landings.
Powdery mildew gradually spreads to the entire petunia bush
Late blight
The disease affects all members of the Solanaceae family, and petunia is no exception. It is possible to identify late blight at the initial stage by the brown shade of the leaves and shoots at the base of the bush. In the future, the disease completely spreads to the entire plant.
With late blight, the petunia bush first dries out and then rots
White rot
This disease is caused by the marsupial fungus. Initially, weeping brown spots appear on the leaves and stems of the petunia, which subsequently become overgrown with a thick white bloom. The damaged parts become soft, so food and moisture cannot pass through them. This leads to the fact that the tops of the bush begin to wither. The infection penetrates into tissues through mechanical damage on the surface of shoots and leaves.
The causative agent of gray rot remains viable in the soil for 3 years
Brown spot
The disease is manifested by rusty spots, which are localized on the leaves and shoots of petunia. Subsequently, concentric areas are clearly visible on them. Initially they have the shape of a circle, and then they lengthen. As a result of sporulation of the fungus, light spots are formed on the affected areas. As a result, the plants gradually wither.
Brown spot develops in high humidity for a long time
How to treat petunia for diseases
It is necessary to deal with petunia diseases in a comprehensive manner. For this, you can use chemicals and folk remedies. This will not only stop the further spread of the fungus, but also prevent its reappearance.
You can learn more about the diseases of petunia in the proposed video:
Drugs
Chemical fungicides have a depressing effect on pathogens. You need to use them according to the attached instructions. In this case, processing should be done in dry, calm weather, observing all personal safety measures.
It is necessary to spray not only the affected petunia bushes, but also healthy ones, as a preventive measure. During treatment, the treatment should be done 3-4 times at intervals of 7 days.
Effective drugs that help fight petunia diseases:
- Ridomil Gold.
- Speed
- Ordan.
- Hom.
- Quadris.
- Topaz.
For the treatment of chlorosis, you need to use "Iron Chelate". The drug must be diluted in water and poured over the petunia. Apply the remedy every 10 days until the signs of the disease are completely eliminated.
You need to use the ready-made solution on the day of preparation
Traditional methods
These funds should be used as a preventive measure. In the event of a massive spread of the disease, they will be useless. In this case, you need to use chemicals.
Recipes for folk remedies for petunia diseases:
- Heat 5 liters of water to 40 degrees.Add 200 g of wood ash and 40 g of grated laundry soap to the liquid. Insist 4 hours, stir, peel. Spray the bushes 3 times at intervals of 3 days.
- Dissolve 80 g of soda ash and 10 ml of liquid for dishes in 5 liters of hot water, mix. Cool and use for processing. Spray the bushes at intervals of 3-5 days.
- Dissolve 50 g of mustard powder in a bucket of water. Use to spray and water petunia bushes every week.
Petunia pests
Petunias can be harmed not only by diseases, but also by pests. They feed on the sap of the plant and thereby weaken its immunity. Therefore, you need to study the main signs of the appearance of pests on petunias (photo below) and how to deal with them.
Aphid
Small pest, the body length of which does not exceed 0.3-0.8 mm. Forms numerous colonies, which are localized on the tops of young shoots of petunias and on the back of the leaves. The pest feeds on plant sap, which leads to deformation of the plates. Weakened petunia ceases not only to bloom, but also to develop.
Aphids are a dangerous pest and vector of viral diseases
Spider mite
A pest that cannot be seen with the naked eye. In case of damage on the leaves of petunia, small light dots appear, which are initially localized along the edge. Subsequently, a thin cobweb appears on the tops of shoots and flowers, which is a characteristic feature of this pest. The plant takes on a dejected look and stops growing completely.
To destroy spider mites, you need to use acaricides
Thrips
The pest is 1.5 mm in size, with a dark brown body color. Forms small clusters that can be seen on the top and back of the leaves. It is possible to identify a lesion at an early stage by light dry stripes on the plates. In this case, the petunia begins to wither, and the flowers and buds are deformed.
In case of mass infestation, green pest excrement appears on the leaves
Whitefly
A flying pest of white color in the form of a small fly. The provoking factor is high humidity and temperature. Whitefly is a carrier of a sooty fungus that can cause severe damage to petunias. You can identify it by touching the plant. In this case, a white cloud flies upward. The pest is localized on the back of the leaves.
Mostly whitefly appears in the greenhouse
Slugs
This pest causes irreparable damage to the petunia. But he feeds on her young juicy leaves, as a result of which holes appear on them. This negatively affects the decorativeness of the plant.
Slugs are nocturnal, which makes it difficult to fight the pest
How to deal with pests
Chemical and folk remedies can be used to destroy and scare away pests on petunias. The former should be used when there are clear signs of defeat, when any delay can lead to serious consequences. The second remedies are more suitable as prevention.
Drugs
To combat pests, you need to use special chemicals that initially cause paralysis, and then the death of insects. They must be used strictly in accordance with the instructions.
Effective drugs for pests on petunias:
- Actellic.
- Inta-Vir.
- Confidor Extra.
- Aktara.
Folk remedies
This method of pest control on petunias is suitable at the initial stage of damage or as a prophylaxis. If distributed on a large scale, it may be ineffective.
Pest Control Recipes:
- Grind 100 g of garlic cloves until smooth. Pour 1 liter of water, leave for 24 hours.At the end of the waiting period, bring the total volume of liquid to 5 liters and spray petunia bushes from pests. Repeat every 10 days.
- Finely chop the shoots and leaves of marigolds (200 g). Pour the resulting mass with 5 liters of water, stand for 6 hours. Then strain and use for processing. Repeat every week.
- Take tobacco dust, mustard, liquid soap and wood ash 100 g each. Pour 10 liters of water. Insist 12 hours, peel. Apply to petunia bushes 1-2 times a week.
Prophylaxis
In order to prevent damage to the plant by pests and diseases, you need to adhere to simple rules. They cannot completely exclude such a possibility, but they allow you to minimize it.
Preventive measures:
- avoid thickening of the landings;
- disinfect the soil for planting;
- air the seedlings regularly;
- control humidity and air temperature;
- remove plant residues in a timely manner;
- lime acidic soil;
- fertilize regularly with phosphorus-potassium mixtures;
- periodically spray with drugs;
- do not overflow.
Conclusion
Knowing the diseases and pests of petunias from the photo, you can determine exactly what to do in each case. To do this, it is only necessary to periodically inspect the plants in order to identify the problem at an early stage. This will minimize damage and quickly restore the plant.
