Late blight is a fungal disease of potatoes and some nightshade crops. This infection is often underestimated by summer residents who consider its manifestations to be just a cosmetic defect of the affected plants. In years favorable for the development of late blight, the yield loss can reach up to 15% and higher. And this is not all the troubles associated with the disease.
The harvested tubers, individually affected by the disease, may be spoiled by the middle of winter, because the infection remains on their surface, and can pass on to healthy ones, causing them to spoil.
The pathogen of late blight can get on tubers in several ways:
- During harvesting with infected tops.
- During cultivation when planting infected tubers on the same field, or from diseased tubers that were not removed from it in the previous season.
- During storage in case of non-compliance with the temperature regime (above 5-6 degrees).
To protect potatoes from late blight, there are several effective methods. They help reduce the likelihood of infection on the site and contain its spread.
Methods of controlling late blight
There are not many ways to combat late blight before infection and already diseased landings, and all of them fit into typical procedures for gardeners:
- Processing seed potatoes before planting with special means to prevent their infection.
- Treatment of healthy plants with drugs that prevent infection of the bushes (their terrestrial part).
- Treatment of infected plants with agents that reduce the activity of phytophthora fungus or completely destroy them.
- Planting late blight resistant potato varieties.
Each of these methods is implemented at a specific time. So, pickling should be done before laying it for storage (the option is suitable only for seed tubers) or before planting sprouted potatoes in the ground.
Prophylactic agents begin to be used after the potato has grown to 18-25 cm in height, and medicinal ones - when the first signs of the disease appear on single bushes.
Compliance with agricultural technology also plays an important role. First, only healthy tubers must be selected for planting. Secondly, potatoes need not be planted too often so that each bush gets both light and air. Thirdly, the provision of potatoes with mineral elements and moisture, as well as regular care. All this will allow you to grow really strong bushes that can independently resist late blight.
Late blight: a nightshade disease (video)
Spraying tubers or dipping them in a miraculous solution, with the help of which not a single "sore" sticks to them, is far from a miracle and not news. In the agricultural market there are a huge number of such funds:
It is recommended to use them 2-3 days before landing strictly according to the instructions. This method avoids the infection of tubers with fungal and other diseases from the soil. Also, some of the tools on the list have the property of increasing immunity in plants, so that they can build up a fairly powerful green mass and independently resist diseases.
Prevention of late blight
After emergence, the confrontation of late blight should not stop. Regular treatment with special agents (fungicides) will prevent phytophthora mycelium from settling on leaf blades and starting its destructive activity. Such measures are considered preventive, but their effect exceeds all expectations: when the neighboring potato fields turn brown, the processed one is green until the very frost.
The following drugs are used to prevent the outbreak of late blight on potato plantings:
- Ekosil, Epin, Oksigumat - from the moment of emergence of seedlings above the soil surface;
- Ridomil MTs and Artsedil - for the first processing of potatoes on sprouts with a height of not more than 20 cm;
- Oksikhom, Khom - for multiple processing of crops before flowering;
- Ditamin M-45, copper oxychloride - for processing plantings after flowering;
- Halben, Polycarbocil, Acrobat - for processing plantings at any time during the growing season.
Folk remedies also have fungicidal properties - an infusion of garlic, a solution of kefir with iodine, Bordeaux liquid. Despite the excellent prophylactic effect, these drugs are becoming less popular, since in order to completely eliminate the danger of infection with late blight, the treatment must be repeated with an interval of 7 days throughout the growing season.
Potato treatment for late blight
If the occurrence of late blight on potatoes could not be avoided, it is recommended to use products with a pronounced fungicidal effect, which literally suppress the fungus, even if it managed to penetrate the plant tissues. As a rule, the following drugs are used for this:
- Artsedil, Ridomil and Oksikhom - for the treatment of bushes that have not yet bloomed;
- Ditamin, Oksikhom and Kuproksat - for processing bushes at the end of flowering.
Treatment is a course of 3-4 sprays at weekly intervals. This is enough for the bushes to restore green mass, and the fungus will die.
Planting resistant varieties
The least expensive way to avoid outbreak of late blight on the site is to plant varieties resistant to late blight. Fortunately, there are not so few of them now, and lovers of the special appearance of tubers (their shapes, colors) can choose a variety to their liking.
The most resistant varieties to late blight include:
The varieties indicated in the table are sufficient to provide summer residents with tubers that are diverse in terms of ripening, purpose and taste for the whole year.
Growing potatoes without the risk of late blight is not so simple. However, with the application of force and due diligence, you can provide yourself with a healthy crop.