Late blight is a disease provoked by fungus-like microorganisms from the Phytophthora family. The name of the pathology is translated from Greek as "a destructive plant." In total, 70 varieties of parasites are known. Signs of infection can be seen on trees, grass and shrubs. Mycelial organisms live on the surface of gardening tools, in the soil cover, aboveground and underground organs of affected plants.
Types of late blight
Famous species include:
- Phytophthora infestans Mont de Bary. It affects potatoes and other nightshade, activated in the period from May to August;
- Phytophthora fragariae Hick. There are two forms (var. Rubi, var. Fragariae). From microorganisms of this type, a crop of raspberries, strawberries and buckwheat can die;
- Phytophthora cactorum Schroet. Symptoms that indicate infection occur on trees from families such as dogrose, beech.
If you know how to deal with this disease, you can save your harvest from this disease.
Read an article on late blight of potato.
Symptoms of late blight
To choose the methods of struggle, you need to conduct a diagnosis. Usually the examination is limited to inspection of the plant.
It should be noted that the best therapy in any case is timely prophylaxis.
The gardener should be concerned if:
- on stems, leaves and roots, the following spots of gray, brown, black or lilac-brown hue appeared;
- a whitish coating appeared on the back of the leaf blades, characteristic pigmentation formed on the front;
- inflorescences darkened and fell;
- the fruits were first stained and then blackened.
The last symptom often becomes a reaction to violations made during the cultivation of agricultural and horticultural crops. It is quite difficult to save the affected plant. It all depends on what stage the disease was identified.
The difficulties arising at this stage are due to a latent type of infection or the negative influence of abiotic factors. The germ remains susceptible to Phytophthora fungi throughout the growing season. Rot caused by late blight, has a dry and hard surface. If untreated, the affected plant will gradually dry.
Phytophthora can develop due to the following factors:
- insufficient air;
- the presence of a protective shelter;
- condensation formation;
- ignoring the optimal temperature;
- wrong crop rotation;
- excessive planting density;
- excess nitrogen and lime in the soil;
- lack of manganese, potassium, iodine and copper.
Blight is called an infectious plant-eater. First, the disease affects the leaf blades located below. Gradually, spots capture healthy tissue. As a result, the plant rots or dries. Dark patches appear on infected tubers, due to which decomposition begins.
Phytophthora formations on the fruits grow in depth and breadth. Both green and ripe vegetables are at risk.
Causes of late blight
Blight is transmitted from a diseased plant to a healthy one through direct contact, through the ground and downwind. Malicious spores spread throughout the site, “traveling” on the soles of the gardener. Do not forget about pets and insects. They can also become carriers of infection.
The causative agent is able to live in soil cover for several years. In this case, its activation will occur upon the occurrence of suitable conditions. You can get rid of the disease with the help of chemicals and alternative methods.
Prevention of late blight infection in open ground
It is one of the most important stages. Preventive measures include:
- the purchase of varieties that are resistant to late blight. It is best to give preference to early ripe hybrid varieties;
- pickling material before planting;
- choosing the right place. In this case, you need to focus on the needs of the planted culture;
- following the recommended sowing dates;
- crop rotation compliance. For example, tomatoes cannot be planted after other members of their family. Their close proximity is also unacceptable;
timely carrying out agricultural procedures (loosening, mulching, top dressing, trimming, garter bushes); - landing suitable neighbors. For tomatoes, this is garlic, curly beans, onions, peas, corn, marigolds;
- proper watering. Water must be poured under the root, it should not fall on leaves and fruits.
Read about late blight on tomatoes.
At a high lime content, onion husks and peat should be added to the hole. The earth around the bush should be sprinkled with sand.
Plants should not be planted too close together.
Using immunomodulators, the gardener will be able to increase the stability of crops. At the same time, one should not neglect the cleansing of the soil from garbage and waste that can become sources of infections.
The complex of preventive treatment often includes spraying Trichodermin and Fitosporin-M.
There are a lot of methods by which it is possible to protect or cure a plant from late blight. It is important to carry out processing in dry weather. But it will have to be postponed not only due to precipitation. Another factor that can do much harm is strong winds. You should also pay attention to air temperature.
How to cultivate the land
For this purpose, microbiological preparations and fungicides are used. The latter are introduced into the ground in spring (4 weeks before planting) and in autumn.
It should be noted that during flowering, chemical treatment is contraindicated. This fact is due to the high risk of bee damage.
Among gardeners, the following preparations are especially popular: Ordan, copper sulfate, Trichodermin, Bordeaux mixture, Fitosporin-M.
Greenhouse preventive measures
So that the plants in the shelter do not suffer from this ailment, the gardener must monitor the temperature and humidity.
The recommended measures also include:
- Disinfection of equipment and premises before boarding. At this stage, sulfur drafts can be used. Processing must be carried out in full compliance with safety regulations.
- Compliance with agricultural requirements. Watering should be rare, but plentiful.
Neglecting them can lead to the death of the entire crop. Regular preventative treatment minimizes the risk of infection with late blight.
Infections in a greenhouse
Late blight is a disease that cannot be cured completely. Crops can be saved from it by suppressing the vital activity of harmful microflora. Means for treating plants planted in a greenhouse and in an open area are the same. In any case, there should be several sessions, otherwise the beneficial effect of chemical compounds and alternative methods is unlikely to occur.
It should be noted that when phytophthora is destroyed in a greenhouse, the risk of poisoning is much higher than when processing outdoors. To avoid this, the gardener must follow all safety precautions.
How to process a greenhouse from late blight
All agrochemicals and pesticides used in agriculture are listed in the State Catalog. To get rid of late blight, drugs such as:
- Concento - phenamidone, propamocarb hydrochloride;
- Sectin Phenomenon - mancozeb, phenamidone;
- Previkur Energy - fosetil, propamocarb;
- Thanos - cymoxanil, famoxadone.
Home is especially popular with summer residents. This fungicide includes copper oxychloride.
Many as a therapeutic agent use Furacilin, Metronidazole and Trichopolum.
Among pesticides, Fitosporin leads. It can be combined with other drugs. The Order is a hazard class 3 fungicide. The frequency of use is determined by the duration of the therapeutic effect. The solution is prepared according to the attached instructions.
You can also use potassium permanganate, calcium chloride, brilliant green, boric acid, Bordeaux mixture, copper sulphate and calcium nitrate.
The fight against late blight with the help of folk remedies
Their list is quite extensive. To achieve the maximum effect, alternative methods should be used in parallel with chemical preparations.
| Means | Preparation and use |
| Garlic infusion | 100 g of crushed heads are poured with one glass of water. Insist for 24 hours. It is filtered and added to a solution of potassium permanganate (0.1%). Between sprayings should pass at least 12-14 days. |
| Ash | It is used both for dusting and for preparing a solution. The latter is made from 5 kg of ash and 10 liters of liquid. To enhance the sticking effect, liquid soap is added. |
| Acetic acid | It will take a bucket of water and half a glass of table vinegar. Plants are treated whole. |
| Toothpaste | For 10 liters of fluid, take one tube. The bushes are sprayed whole, it is advisable to do this after the rain. |
| Rotted hay | It will take 1 kg of rotten hay, 100 g of urea and 10 liters of heated liquid. The composition is insisted 3 days. |
| Copper wire | Before planting, the roots of the seedlings are carefully wrapped with copper wire. It is preliminarily calcined. |
The gardener can choose any method from those listed above. The main thing is to carry out prevention and treatment on time. Otherwise, late blight quickly spread throughout the site and ruin the entire crop.
