Verticillium wilt of strawberries: description and treatment of the disease, preventive measures
Growing strawberries is often overshadowed by the defeat of the plant by various infections. Not the last place among the diseases to which the culture is susceptible is verticillium wilt, caused by the multiplication of microorganisms. It will be useful for gardeners to learn how to deal with a parasitic fungus that causes the death of strawberry bushes and reduces the quality of the crop.
Description of the disease
Verticillium wilt of strawberries is caused by fungi of the Verticillium species, which like to settle on other garden crops. The microscopic creature lives in the soil, parasitizing on weed grasses, and can be transferred to household plots through shoes, agricultural tools, as well as with affected parts of plants and seeds. It is known that sandy soil is favorable for the reproduction of a microorganism - plants growing on such soil can die in a matter of days if they are damaged by a pest.
Verticillium wilting of strawberries takes on a more protracted character on sandy and clay soils. One way or another, the bushes begin to hurt, their roots and young shoots suffer. As a rule, their vital activity stops, but before that, the infection can be transferred to healthy strawberries.
This is due to the fact that the mycelium of the fungus releases toxins, getting into the water, they penetrate into the tissues of the plant through the root system, which is destroyed in the first place.If you look at such a strawberry root, you will notice that it is smaller than the normal size, and its texture has become porous and loose. As a result of damage, it can no longer receive moisture and nutrition from the ground and dies for this very reason.
In some cases, the bush survives and is able to grow again in the spring, but this only applies to certain resistant varieties with low susceptibility to the disease.
Ways of infection
The fungal microorganism is spread by various means, such as spores. But also favorable conditions for its appearance are:
- lack of ventilation of the beds;
- too dense foliage of bushes;
- insufficient amount of sunlight;
- large amplitude of high and low temperatures during the day and at night;
- high level of humidity.
In such a climate, the organs of the microorganism (hyphae) are able to actively penetrate into the hairs of the roots. When they are additionally injured by agricultural tools or insects, the plant becomes infected and dies faster. The defeat of the culture can occur unnoticed by the gardener, while the pathogen has been in the ground for several years.
Symptoms of the disease
Inexperienced gardeners often confuse the first signs of verticillium wilt, expressed in the drying of the lower leaves, with signs of late blight and fusarium. But with these diseases, as a rule, fruiting is reduced or completely absent, while in our case, due to lack of nutrition, the berries become smaller and dry. Diseased plants can be identified by their appearance:
- leaves and stems may acquire yellowish-red hues;
- the edges of the leaf blades become dry and fold, sometimes they fold along the vein passing in the middle;
- the plant, as it were, is adjacent to the ground and becomes lower in height, forming an almost perfect circle on the soil;
- petioles and stepsons are covered with bluish and brown spots and stripes;
- tips of young roots turn black.
The disease can affect both young and adult bushes. If the strawberries did not die immediately, their complete death may occur in a couple of years, however, the diseased species will speak for itself, it is better to get rid of such bushes in order to avoid infection of neighboring plants.
Treatment
In light of the danger that verticillium wilt poses to strawberry bushes, the question of whether affected plants can be treated becomes especially topical. Yes, you can and should, especially at the first sign of wilt. To reduce the number of microorganisms and their destruction, the use of chemicals is envisaged, the handling of which must be prudent. This is a group of pesticides, as a rule, copper acts as a toxic substance in them, while lime neutralizes acidity. Before use, be sure to read the instructions.
The most effective remedies for wilt are as follows.
- "Maksim" - It is used for soil disinfection. For humans, it does not pose a danger. Usually used for spraying or watering seven days before flowering, and the effect occurs in a day. One ampoule is enough for 2 liters of water, and about 100 ml per bush.
- "Fundazol" - an effective anti-fungal drug. 10 g of the substance is diluted in 10 liters of water, the solution is designed to process 10 m2. In humans, the composition can cause irritation of the mucous membranes and skin, therefore, when working, it is necessary to wear a protective mask and gloves.
- "Bordeaux Blend" is a composition with active ingredients such as quicklime and copper sulfate. It is necessary to dilute 450 g of lime and 300 g of vitriol in 10 liters of water.
Biological preparations are more preferable, as they do not spoil the soil and are safe for human health.
At the same time, their effectiveness is no less high than that of chemicals.
- "Fitosporin" in the form of a paste, powder and solution suggests different ways of use, actively affects fungal spores, causing their death.
- "Phytodoctor" - a fungicidal agent used for watering affected plants. The solution should be prepared two hours before treatment from 10 liters of water and 30 g of the substance. Water the beds in the absence of the sun.
- "Phytocid-r" - is produced in the form of a liquid, 10 ml of which is diluted in 10 liters of water, irrigate the soil of the beds in the evening.
- "Trichodermin" - the most powerful remedy against verticillium wilt. Its advantage is the possibility of using it before planting a crop. First, the roots of the seedlings are soaked in the solution for several hours, and then the soil is sprayed. For preparation, you need to take 200 ml of the drug per 10 liters of water.
Folk remedies are used more to prevent the development of the disease. Spraying of plantings with chamomile decoction and infused charcoal is often used. It is also recommended in the spring and after harvesting to water the beds with hot water, a solution of slightly diluted potassium permanganate, or add 15 drops of iodine to a bucket of water. The use of these antiseptics helps to prevent not only verticillium wilt, but also many other diseases provoked by pathogenic fungi.
Preventive measures
In order to prevent such a nuisance, especially since it is quite difficult to deal with it, it is necessary to adhere to the established rules of prevention.
It makes sense to arm yourself with the following recommendations of experts:
- 5-6 years before planting strawberries, do not plant peppers, blackberries, beets, melons, nightshade crops (tomatoes, potatoes) on the beds;
- choose loamy and sandy loamy soils for cultivation;
- monitor the maximum drainage of the soil, avoiding stagnant water in it - this requires regular loosening, weeding and mulching;
- before digging the site, treat with bleach and fungicidal preparations;
- periodically water the beds with antifungal solutions;
- do not abuse nitrogen fertilizers that can activate the growth of the mushroom population, but timely introduce potash and phosphorus additives into the soil;
- flowers such as chrysanthemums and roses should be cultivated away from strawberry plantations.
You can also protect plants by planting varieties that are immune to wilting, such as Lakomka, Figaro, Mize Schindler, Festival Chamomile, Favorite, Wima Zanta. If a diseased bush is found, then it will have to be removed, after which the bed and the area around it should be treated with special means. Unfortunately, in the active stage of the disease, it is impossible to fight verticillium wilt, and highly toxic drugs can cause significant damage to the earth.
That is why the destruction of the bushes remains a reasonable solution, while the soil will be unsuitable for sowing for about 5-6 years.
For information on how to treat strawberries for diseases and pests, see below.