Late blight is a formidable fungal disease that affects mainly nightshade (potatoes, tomato, eggplant, pepper, etc.). Its fungus is called Phytophthora infestans, which is brought to the site most often with purchased tubers or seedlings. Heap leaves for the winter can also be heaps of leaves.
Overwintering spores of late blight cause disease in new plants. Fighting this infection is very difficult. It’s easier to prevent its development.
Phytophthora, the methods of control of which consist primarily in prevention, affects plants mainly in the second half of summer. Therefore, it is important not to miss the timing of planting potatoes. The best time is the second decade of April. Before planting, the soil must be loosened. Many summer residents during the laying of tubers in the hole throw there a handful of manure. In this case, it is important to observe the dosage correctly. The fact is that an excess of nitrogen in the soil is one of the main reasons for the development of late blight. Therefore, do not fertilize the soil too much with manure.
Some excess of potash and phosphorus fertilizers, on the contrary, reduces the risk of a disease such as late blight. Methods of dealing with it are quite complex and often ineffective. Therefore, another excellent way to prevent its development can be considered the use of only resistant varieties on the site. It can be "pace", "Gatchina", "table 19" and others.
Often late blight on potatoes is manifested if it has been grown for several years in the same place. In this case, gradually accumulating, the infection significantly reduces productivity. You should also not plant tomatoes near the potato field. In the latter case, both crops may be affected. Root crops before planting are necessarily sorted out, discarding all small, ugly and sick ones. It is best to withstand them for another week at a temperature of 16-18 grams. Celsius. During this period, late blight spots become noticeable, so removing diseased tubers will not be difficult.
Potato late blight most often affects it in rainy cool summer seasons. In this case, it is worth reducing the amount of watering. It is very important to remove weeds that weaken plants in time and carry out hilling.
A thick layer of earth above the tubers will not allow spores of fungus from branches and leaves to penetrate to them.
If nevertheless phytophthora touched your crops, you have a lot of hard work to do. First of all, it is necessary to remove all infected stems and leaves. Then the potatoes are treated with fungicide preparations. Bordeaux fluid also copes well with this disease. However, it is best to use new tools. The fact is that late blight, the methods of dealing with which also involve the use of copper-containing preparations, mutates very quickly and adapts to all the chemicals applied to it.
In some cases, environmentally friendly microbiological agents of a new generation will also be useful. The principle of their action is extremely simple: the bacteria that enter them are activated when they enter the water, and when the solution is applied to the branches and stems, they begin to destroy the fungus. With rainwater, they penetrate the soil, helping to cleanse the disease and tubers. Thus, you can cope with the disease "late blight." Methods of dealing with it with chemicals, of course, can be considered more radical. However, the use of microbiological agents will make it possible to obtain a crop that is not contaminated with harmful compounds. In this case, the decision remains with the owners of the site.