Among the diseases of tomatoes, one of the most common is late blight or late blight. When this fungal disease appears on tomato bushes, you can immediately notice its signs - small dark spots on the leaves, brown and drying leaves, as well as blackening of individual sections of the stem. Over time, the fruits themselves begin to turn black, and the bush withers and dries up.
Most often, this disease overtakes tomatoes during prolonged rainy, cool and cloudy weather. Let's try to figure out how to prevent disease in the beds, what preventive measures to take and what methods of dealing with an already manifested problem.
The main causes of late blight
Fungal diseases live by the proliferation of spores, which are found almost everywhere. Gardeners need to take all measures to prevent these spores from developing, and, if possible, even reduce their number. There are several factors that favor the spread of late blight:
- There is a lot of lime in the soil. So that the soil does not sour, summer residents carry out liming and sometimes get too carried away with this process. Excess lime on the site attracts fungus.
- Thickened tomato plantations. Tomato beds in the greenhouse, due to its small size, look like the impenetrable jungle of the Amazon. The "climatic" conditions in such a closed cultivation, with a lack of fresh air and high levels of humidity, are an excellent place for the development of phytophthora.
- Sharp changes in night and day temperatures. By the end of the summer season, the nights get colder. The change from a hot summer day to a cool night contributes to a large amount of morning dew, which increases the amount of moisture in the beds.
- Immunocompromised plants. In plants, as well as in humans, the weak will get sick faster than the strong. With insufficient fertilization of the soil, vegetable crops lack some microelements. Their weakened immunity can cause late blight.
Prevention of phytophthora
- The calcareous soil on the site must be restored by introducing peat to the summer cottage and coarse river sand in the aisles.
- When planting tomatoes, it is necessary to take into account the predecessors and observe the crop rotation.
- When planting tomato seedlings in beds, strictly observe the recommended intervals between plants and between beds in order to avoid thickening in the future.
- When growing tomatoes in a greenhouse, do not forget about regular ventilation of the room. Watering is best done in the morning so that moisture is absorbed into the soil by the evening.
- In cool, cloudy weather with a high level of humidity, it is not recommended to water tomatoes at all. It will be enough to loosen the soil in the beds.
- Regularly apply fertilizing with the necessary trace elements by watering and spraying.
- Use spraying tomatoes with various biological products or solutions from folk recipes.
- Plant tomatoes only of those species and varieties that are resistant to late blight and other fungal diseases.
Spraying tomatoes against late blight
Preventive spraying of tomatoes should be carried out only in the morning and in warm, dry weather. Among the many different remedies for late blight, it is recommended not to repeat the same prescription or drug from year to year. This fungal disease is able to adapt to different conditions and means.
The first spraying should be carried out as soon as the tomato seedlings are planted. And the next ones - regularly 2-3 times a month.
Means of fighting late blight
- Infusion of garlic with potassium permanganate. Greens or garlic bulbs (about one hundred grams) must be chopped to a puree and poured over with two hundred and fifty milliliters of cold water. After 24 hours, strain the infusion through double gauze and add a large bucket of water and 1 gram of potassium permanganate. This infusion can be used two or three times a month.
- Trichopolus. In three liters of water, you need to dissolve three tablets of this drug and use the solution every fifteen days.
- Milk serum. The serum must be combined with water in equal proportions. The solution can be used daily starting from the second summer month.
- Ash. Sprinkling the row spacings with wood ash is carried out twice a season. The first time - 7 days after planting tomato seedlings, and the second - during the formation of the ovary.
- Infusion of rotten straw or hay. To prepare the infusion, you need to use rotten straw or hay (about 1 kilogram), urea and a bucket of water. Within 3-4 days, the solution should be infused. Strain it before use.
- Milk with iodine. Spraying with this solution is carried out 2 times a month. You need to mix 500 milliliters of milk, 5 liters of water and 7-8 drops of iodine.
- Salt. It is recommended to spray green tomatoes with this solution once every 30 days. 1/2 cup salt is added to 5 liters of gadflies.
- Copper sulfate solution. It is used once before the beginning of flowering of vegetable plants. Add one tablespoon of copper sulfate to a five-liter container of water.
- Yeast. It is used when the first signs of late blight appear. 50 grams of yeast must be diluted in 5 liters of water.
- Fitosporin. This preparation (in diluted form) is recommended to water the beds in the greenhouse before planting tomato seedlings. You can add "Fitosporin" every other day to the water for irrigation. And spraying can be started when ovaries form and repeat them regularly every one and a half to two weeks. It is necessary to prepare the solution strictly according to the instructions on the package.
Fight against late blight in greenhouses
Disease is easier to prevent than to cure. This also applies to phytophthora. Before planting seedlings in a greenhouse, it is worthwhile to thoroughly clean and process them. The preparatory work consists in removing cobwebs and dirt from the side and upper surfaces, in cleaning the beds from plant waste.
It is recommended to carry out preventive fumigation of the greenhouse with burning coals and a small piece of wool. In such a smoky state, the greenhouse should be left for a day with doors and windows tightly closed.
Some summer residents carry out ash - tobacco dusting of greenhouse beds or spraying with solutions EM drugs.
