If powdery mildew appeared on the petunia - how to deal with this scourge?

Petunia is not only an indoor, but also an outdoor plant, which is used to decorate flower beds in many countries of the world.

Although it is unpretentious in leaving, sometimes it is powdery mildew. Can I get rid of the disease?

So, from the article you will learn about powdery mildew, how it affects a flower and how you can successfully fight it.

Briefly about the plant and its features

Cascading and ampelous petunias grow faster than ordinary ones. If you solve the problem with additional lighting, a central shoot will quickly form, and then the side shoots, extending from it at right angles. With a lack of light, the side shoots grow worse and grow up. You can adjust the shape of the bush by changing the conditions of detention.

Experienced gardeners pinch bushes during the growth period. They do this to inhibit the development of petunias. Breeders bred hybrid varieties, laying in them a beautiful bush shape. When growing them do not use special agricultural techniques. They will be needed for seed propagation of ampelous petunias: the bush is formed by pinching, but still it will not be possible to turn it into an attractive “ball”.

Important. How to prevent the extension of long lashes with ampoule petunias? It is necessary to prevent their flowering until a bush is formed. It takes 3 or more months.

Disease Background

Powdery mildew or mycelium of parasitic powdery mildew fungi is a parasite that invades petunia cells and drinks all juices from it. If you look at the white coating, soon the lower leaves will turn yellow, hang and fall (why do the leaves of the petunia turn yellow?).

In those places where the mycelium is attached, ulcers appear. Living tissue disappears, as parasites "eat" it. It’s hard not to notice powdery mildew: lack of nutrients affects not the best way on petunias. Due to disruption of the photosynthesis process, it will die if urgent measures of integrated control are not taken.

Causes

Powdery mildew is a fungal disease caused by parasites that live in the upper layers of the soil. She rarely infects petunias if the grower takes care of her. He knows that powdery mildew spores are activated in the following cases:

• Cool damp air (day and night temperatures are around +20 degrees Celsius, and humidity exceeds 70%).
• Excess nitrogen in the soil.
• Thickness of plantings.
• Incorrect and irregular watering.

Powdery mildew sometimes affects petunia for other reasons. Infection does not occur due to non-compliance with the conditions of detention. The pest comes to it from neighboring crops, through water or due to non-observance of precautionary measures by the grower himself (cutting a healthy plant with the same tool without treatment with an alcohol solution).

Diagnostics

For the first time, they talked about powdery mildew in the Russian Federation at the beginning of the 20th century. Its causative agent is the fungus Sphaerotheca pannosa. It is easy to recognize an infected plant:

1. First a whitish coating appears. It is noticeable on leaves and inflorescences.
2. A few days later, droplets appear, similar to dew, on stems and petals.

Experienced flower growers claim that the disease spreads from the lower leaves to the upper parts, including to the buds. Without taking action, the plant will rot and die.

Attention. The best way to determine that powdery mildew develops on petunias is to carefully examine it in daylight.

How to get rid of a problem?

To cure petunia, review the conditions of detention:

1. It is watered less often and only after they notice that the topsoil has dried out.
2. The flower grower ceases to spray it, and the flower pot is rearranged on the windowsill, which is "drowning" in the sun.
3. It picks off leaves that are close to the edge of the ground. This simple action prevents the spread of the disease to the upper parts of the plant.

Not all flower growers use drugs in the fight against powdery mildew, even knowing their effectiveness. They believe in folk methods. Petunia will recover if treated with a solution prepared from:

• 250 ml of milk;
• 750 ml of water;
• 1 tsp salt.

After mixing the above ingredients, pour it into a bottle and petunia is sprayed using a spray bottle.

The fungicidal drug treatment algorithm

1. Change in plant conditions. It is cleaned on a windowsill drowning in the sun and less often watered with petunia.
2. Remove infected areas, i.e. buds, yellow and flabby leaves.
3. Remove the top layer of soil, and instead pour another - processed.
4. Spray with fungicides, diluting them according to the instructions from the manufacturer.
5. Make sure that the solution gets on all parts of the petunia.
6. In severe cases, a plant is dipped in a container with a solution.

Effective folk remedies

1. Soap solution with soda ash. To prepare it, they take 20-25 grams of soda, 5 liters of hot water and 5 grams of liquid (ground household) soap. The mixture is cooled, and then it is sprayed with a basal plot of soil. The frequency of the procedure is 2 times in 7-10 days. Do not spend it, seeing that the signs of powdery mildew have disappeared.
2. Weak solution of potassium permanganate. It is prepared by dissolving 2-3 grams of potassium permanganate in 10-13 liters of water. The frequency of processing is once every five days. The number of procedures is 3.
3. A mixture of soap and ash. It is prepared from 1 kg of wood ash and 10 liters of hot water. After mixing and insisting for 5-7 days, add another 5-10 grams of soap to it and process the bush. Before that, filter it. Ash is not thrown out and poured into a pot for feeding.

Tip. The folk remedies described above will not help if the grower noticed powdery mildew on petunias late.

What is better to process from "chemistry"?

In the fight against powdery mildew fungicides help. They destroy the structure of the fungus, inhibiting its development in the cells of the flower.

Fundazole

This fungicide has a wide spectrum of action. It helps if they find diseases of leaves, buds and seeds on indoor plants. The effectiveness of Fundazole is due to the presence of benomyl in the composition.

This substance penetrates the plant through the leaves and roots. After that, it is converted to carbendazim, which exhibits the best properties of fungicide. After treatment, Fundazole remains on the surface. Only partially does it get into the plant. Because of this, petunia is better protected from reinfection with powdery mildew.

Fundazole is sold in a 10 gram sachet. The price is 17 rubles. Dilution method - 1 gram / 1 tsp. water. After preliminary dissolution, the volume of the working solution is adjusted to 1 liter. It is better to combine watering with spraying to remove the fungus. A plant is treated twice a season if it was not possible to destroy it the first time.

Amistar Extra

This combined fungicide is effective against many diseases, including powdery mildew. With his help:

• extend the growing season;
• increase the effectiveness of water;
• improve photoassimilation, nitrogen metabolism;
• inhibit the formation of ethylene.

Amistar Extra is a drug that is released in the form of an aqueous solution. In Russia they sell it in liter cans at a price of 1,500 rubles / 1 liter. A working solution is prepared by mixing fungicide with water at a concentration of 1:10 or 1: 4. After shaking, they treat the plant with it.

Coming soon

Petunia can be cured if you buy contact and systemic fungicide Skor at a price of 8300 rubles per 1 liter. The main active substance in it is diphenoconazole.

For treatment, 2 ml of the drug is diluted in 10 liters of water. It is not used for processing immediately after dilution. Twenty days later, the petunia is treated three times.

Photo

In the photo, offered to your attention below, you can see how the petunia struck by powdery mildew looks and how to deal with this ailment at home:

Preventative measures

Powdery mildew is a common disease. If you follow the recommendations from the list below, petunia will never get sick.

• Growing petunia in a pot on a well-lit windowsill.
• Pots on the windowsill are placed at an impressive distance from each other to prevent the spread of fungal spores.
• If there is no living space left on the petunia, destroy it so as not to infect others.
• The plant is watered in the morning to increase its resistance to disease.
• If you feed it, then only phosphate and potash, and not nitrogen fertilizers.
• It is necessary to spray it with decoctions of horsetail or tansy from time to time.

Conclusion

If you create the right conditions for growth and flowering, powdery mildew does not threaten petunias. Noticing a white coating, urgently take action. Losing time, the plant may die, infecting others standing nearby on the windowsill.

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