Powdery mildew description
Powdery mildew is caused by hundreds of fungal species. It poses a serious threat as it can infect more than 10,000 plant species. It is found on plant stems, flowers, and even fruits, causing the most losses in home gardens.
On plants, powdery mildew appears as white or gray powdery spots covering part of the surface. They can grow rapidly, completely covering the infected areas. Although these fungi do not usually kill plants, they do deplete them. They need plant nutrients to survive.
Pay attention! Unlike most other types of fungus, plant powdery mildew causes more severe cases of the disease in warm, dry weather. Mild infections may go away on their own. But without intervention from the gardener, a severe infection can kill the plant.
At first, it is erased or washed off, but comes back again. The lower leaves are most commonly affected. As the spots increase in size, the mold can spread throughout the plant.
In later stages, foliage may turn yellow, curl, turn brown, and die prematurely. On flowering plants and trees, the fungus can cause early bud drop or reduced flower quality.
Which plants are affected by powdery mildew, how and when does it occur?
The causative agent of powdery mildew is a fungus belonging to the Ascomycetes family, which almost always develops in spring and autumn, during seasons characterized by a hot and humid climate.
It affects plants in shady places more than those in direct sunlight. White disease affects many plants, very different from each other, with the exception of gymnosperms, such as conifers.
Affected areas slow down photosynthesis. The plant stops its growth, up to death with severe infection. The fruits remain small and do not reach maturity.
Mushroom spores are carried by the wind and cannot be avoided. If powdery mildew has been in the past, new outbreaks may be caused by dormant spores in old material or nearby weeds.
Preventive measures against powdery mildew
Despite the many options for control, prevention is still the best cure not only for powdery mildew, but also for other diseases.
- Disease-resistant varieties are selected.
- Ensure sufficient air circulation between plants, dense foliage is more susceptible to infection.
- The sun is the enemy of fungal diseases, so give plants the level of sun exposure they need to thrive. Place plants where they will receive enough light for six or more hours each day.
- Lush greens are more susceptible to powdery mildew so if there is a problem with this disease in the garden, avoid nitrogen fertilization in late summer.
- Avoid over-fertilization. New shoots are more susceptible to infection.
Overhead watering is sometimes recommended as a way to prevent this disease, but this practice can increase the humidity inside the plant. An increase in humidity can trigger an infection or increase the severity of an existing infection.
More info! Water the plants at soil level and avoid wetting the foliage. It is best to water early in the day, as the plants will dry out before dark.
In infected plants, cut off diseased tissue and destroy it. You can not put it in a compost heap, otherwise the infection can spread to other parts of the garden. Nearby weeds can also serve as breeding grounds for spores, keep the beds clean of weeds.
Means for powdery mildew and hands
Healthy plants often recover on their own after weather changes and with proper care to improve air circulation. Powdery mildew disease is treatable, and you do not even have to resort to the use of fungicides, avoiding poisoning bees and other pollinating insects that are beneficial to life and human health.
Pay attention! Early detection of the disease will provide the best way to isolate and potentially fix the problem. Most conventional products are designed to prevent and control powdery mildew, not to treat it. That’s why it’s important to start a control program before powdery mildew appears, or at least at the first sign of it.
For severe infections or widespread problems in the garden, treatment options are available. What treatments can be used to prevent and treat plants affected by powdery mildew?
Prevention and treatment of plants[ /caption] Plants affected by white are treated with a special preparation based on sulfur, which has no contraindications for humans, but prevents infection or blocks it if it is at the beginning.
Powdery mildew fight
- Mix 1 tbsp. a spoonful of baking soda with 1 tbsp. tablespoon of vegetable oil and 1 teaspoon of dishwashing detergent to 1 liter of water.
- 2-3 tablespoons of vinegar are diluted in 1 liter. water. Try carefully because the vinegar can burn the plants.
- Neem is an organic fungicide, follow the instructions on the label.
- 1 part milk is mixed with 10 parts water.
Colloidal sulfur is a classic fungicide that is effective against powdery mildew. It must be used before symptoms appear. It can be sprayed on all susceptible plants to prevent infection.
It is considered one of the most effective and inexpensive remedies against fungi that cause this disease. Sulfur and lime prevent the development of disease spores. When mixed with slaked lime, the solution penetrates the leaves with greater efficiency.
If there is no sulfur, or other specific products, you can prepare infusions and decoctions of garlic and onions. A decoction and infusion of onion peel and garlic cloves is easy to prepare at home. The results are excellent and visible after the first course of treatment.
In the fight against powdery mildew, you can spray the leaves with soda instead of sulfur. Baking soda (sodium bicarbonate) is perhaps the best-known homemade organic powdery mildew solution. While studies show that baking soda on its own isn’t all that effective, when combined with garden oil or liquid soap, it’s highly effective when used early or before an outbreak occurs.
Potassium bicarbonate is approved for use in organic cultivation. It eliminates powdery mildew as soon as it appears, quickly killing its spores.
Acetic acid can control powdery mildew. Too much vinegar can burn plants, but at the same time, higher concentrations are more effective.
Copper sulfate and slaked lime, known as Bordeaux mixture, is considered moderately toxic to mammals and humans. Use sparingly and with care
Milk can also help prevent infections if sprayed weekly on plants in the early stages of an infection. Its effectiveness has been proven in over 60 years of research on many plant species.
Higher concentrations of milk may be most effective and may help prevent infections if sprayed weekly on plants. One experiment showed good results by applying a weekly dose of one part milk to two parts water.
Neem oil is a readily available organic pest and disease control agent. A natural broad-spectrum insecticide that is safer for beneficial insects and mammals.
In the fight against powdery mildew, it shows different results, usually moderate.
To prevent fungus from developing resistance to home spray, it is recommended to change products every week.
Dry conditions and high humidity are the most favorable conditions for powdery mildew formation. The water washes away the spores before they can take root. However, wet foliage is a friend to many other plant diseases. You can try this option at the beginning of the day so that the foliage has time to dry quickly.
Giving plants the conditions they need to thrive is the key to keeping them healthy, disease-free.