Growing vegetable crops has its own characteristics, for example, zucchini, which grows well in the middle zone of our country, does not like temperature changes. Infection by fungal spores during sudden cold weather or heavy rains leads to the development of powdery mildew on zucchini.
The disease develops on the leaves and stem and can completely or partially destroy the crop.To avoid this, you need to know what signs indicate infection, and what methods need to be used for effective control.
What is it: types of disease and areas of plant damage
Even the use of the correct agricultural technology system and high-quality seeds cannot guarantee a good harvest. Plants are often affected by various pests and diseases, one of which is powdery mildew.
It comes in two types:
- A disease that develops on zucchini and other melon crops in the form of a specific coating and is directly called powdery mildew.
- A false disease that most often appears on cucumbers.
The cause of both varieties is a fungus that forms in the soil, with the only difference being that the real disease appears on the leaves from the outer part of the plant, while a false powdery infection first affects their inner side and only at the last stage do spots appear on the outside.
Before choosing remedies for powdery mildew on zucchini, you need to understand its symptoms.
External signs of the disease
Common signs of the disease are the appearance of white streaks on the leaves. They seem to be sprinkled with flour and at first do not cause much concern. However, if you do not immediately begin to treat powdery mildew on zucchini, the disease will quickly spread to the stem and other plants growing nearby.
After just a couple of days, the pleasant white coating takes on a brown tint. This means that the process has moved to a new stage and can destroy the entire plantation, without allowing the fruits of zucchini and other plants in the garden to ripen.
However, despite the similarity, the symptoms of the disease in different plants may differ.For example, on zucchini, powdery mildew causes leaves to wilt. This is due to the fact that the white film does not allow sunlight to penetrate into the leaves and without nutrients they simply die.
Fungal spores can be carried by wind or water and affect other plants in the area. To prevent this from happening, you should take the first steps in case of this disease.
Causes of powdery mildew
The disease actively develops when the weather is hot or rainy. These are ideal conditions for the proliferation of harmful fungal spores. If the lesion is large, not only the leaves, but also the plant vines begin to wither.
There are many causes of powdery mildew. It is often provoked by parts of plants remaining from last year that have not rotted, where pathogenic spores may remain.
In addition, you should pay attention to the following aspects:
- Soil contamination. If there was fungal mycelium on the site last season, its spores could overwinter in the ground and begin activity with the arrival of warmer weather.
- Failure to comply with crop rotation rules on the site.
- Errors in agricultural technology during plowing and tillage.
- The presence of weeds both in the garden and in the areas adjacent to it. They become a haven for harmful bacteria and pathogenic spores.
- Errors when applying fertilizers. For example, excessive fertilizing with nitrogen fertilizers may not only not give the desired results, but also provoke a worsening of the situation. Lack of potassium fertilizers can also cause plant disease.
- Placing shoots too close after development can cause stagnation of water, which increases air humidity and affects the plants inside the vines. As a result, a favorable environment is created for the occurrence of powdery mildew.
- A sharp change in temperature, heat or high humidity is also an impetus for the development of the disease.
- Lack of treatment of zucchini against powdery mildew with protective drugs.
Measures to combat powdery mildew
If upon inspection a small number of spots were revealed on the affected leaves, indicating powdery mildew, such leaves and shoots must be removed immediately. The first steps should be careful: in order not to shake off fungal spores onto healthy plants, you need to carefully put the removed parts in a plastic bag and take them out of the area. It is advisable to burn them immediately.
In the fight against powdery mildew on zucchini, be sure to thin out the bed to allow light for the plants and stop feeding for a while. Then treat the remaining zucchini with chemicals or special preparations based on folk recipes. Adjust watering of plants, avoiding waterlogging and drying out of the soil.
How to help a plant at an early stage?
Before getting rid of powdery mildew on zucchini, you should familiarize yourself in advance with the effects of various agents on both plants and humans after consuming the product. And, of course, when choosing seeds, make sure that they are resistant to this disease.
Before treating with chemicals, you need to do the following: carefully study the contraindications for their use, because they will need to be used more than once. Fungicides such as Topaz, Fundazolom, Quadris and others are most often used for treatment.
Spraying is carried out with a warm solution. For people who are prone to allergies, it is better to give up chemicals and use traditional methods of control. However, even without health problems, it is necessary to use chemicals extremely carefully and under no circumstances eat food after processing until the due date, when the effect of the aggressive components is over.
Popular drugs and their disadvantages
You can fight powdery mildew on zucchini using both folk remedies and medications. Folk recipes will be of particular interest to those who have a negative attitude towards the use of chemicals in growing vegetables and fruits. However, in the most difficult cases, you cannot refuse to use chemicals, as you can completely lose the harvest.
However, here too, spraying should be carried out in accordance with the severity of infection of the entire planting area. Treatment is extremely necessary if more than 10% of the plants are affected by powdery mildew. In other cases, you can use safer options.
One of these measures is to reduce the lesion by cutting out diseased vines of plants. In this case, each time a knife or pruning shears must be dipped into a solution of fungicide and potassium permanganate and cut off several centimeters of healthy vines.
Funds from the people
Folk remedies as a measure to combat powdery mildew on zucchini are effective in the very early stages of plant damage.
The most famous among them are:
- Composition of soda ash and soap. 25 grams of soda are dissolved in five liters of water and 5 grams of liquid soap are added to the solution. The surface soil layer is processed twice with a break of ten days.
- Potassium permanganate solution. You need to take 2.5 grams of the drug per bucket of water.
- An infusion of humus, preferably cow's.Take water and manure in proportions 3:1 Infusion of rotted manure (better than cow manure)
The infusion time is at least three days.
There are other equally effective recipes that can be used to prevent and treat powdery mildew on squash leaves and other plants. Their main advantage is safety for humans.
Chemical methods
You can fight and combat powdery mildew both on zucchini and other plants by treating with chemicals. They must be prepared and used strictly according to the included instructions. In this case, it is necessary, if possible, to pre-pluck the ripened fruits, and the ovaries should be treated with a minimum amount of the drug, since they grow very quickly, and it will be impossible to eat them right away. Despite the low hazard class of most drugs, you cannot eat zucchini after this treatment for about two weeks.
In great demand among gardeners are preparations such as soda ash solution, copper sulfate and Bordeaux mixture, which contain sulfur and copper, which have a detrimental effect on the fungus. Of course, you should not use them constantly, as addiction will occur and this remedy will become ineffective.
Prevention
The best way to protect your garden from powdery mildew and other diseases is prevention recommendations. After all, if such measures are carried out in a timely manner, the disease will not appear at all.
And for this:
- At the end of the season, it is necessary to clean the garden and burn all tops and other plant debris that can become breeding grounds for diseases.
- The soil needs to be dug up before winter so that the powdery mildew spores freeze out in the cold.
- Follow the rules of crop rotation and change the location of planting zucchini and other vegetables every year.They can only be planted in their old place after four or five years.
- Weed and thin out the bed, as well as control watering and fertilizing of plants.
- Pay special attention to ventilation of greenhouses where there is a high risk of condensation.
- It is necessary to inspect the branches of zucchini as often as possible, especially in hot weather, in order to take timely measures to eliminate the lesions.
- Since fungal spores can be carried by insects, it is necessary to carry out preventive treatment of zucchini against powdery mildew with gentle agents.
This approach to the problem will help to correctly assess the situation and choose an effective way to deal with it.
