Phytophthora on cucumbers: description and treatment
Phytophthorosis – an extremely dangerous disease of the fungus leap, which can destroy the entire harvest. Its main danger is the rapid spread and very detailed effect on plants. This fungal disease is not transmitted to one person, but individuals are allergic to fungal spores, which can certainly lead to an acute allergic reaction to the consumption of affected fruits.
Features of the disease
Phytophthora (Phytophthora infestan) is a rapidly progressing fungus that leads an active parasitic life on dacha crops, late lepidoptera on cucumbers is no exception. It means “plant destroyer” in English and does so very intensively. If you do not stop his appearance, in a short time in the process of development, he can completely destroy the harvest. Its particular danger lies in its rare survivability – the fungus is difficult, long, sometimes years, have to be removed, as it is born again silently.
There are over a hundred species of this mushroom formation, all of which are multi-plate, persistently survive the winter in the ground and prefer moist and warm conditions. Late blight most often occurs in greenhouses, which form a cheap microclimate for propagation – a temperature regime of no more than 10 degrees Celsius and a humidity of about 75%. In the early stages, signs of infection on the leaves are difficult to notice because they appear implicit.
When the development of late greenhouse infestation reaches an average level, the size of the brown spots appearing on the plants gradually increases, and the rot spreads throughout the greens.
The rotting fragments emit an unpleasant odor. When plants become diseased, their growth slows, bushes become completely brown, and the crop may die. In these cases, remove infected plants immediately, treat healthy bushes and remove infected fragments.
Why does it appear?
The disease passes quickly from bush to bush. On windy days, spores can spread considerable distances. Weakened bushes are the first to become infected. Let’s name the main causes of the disease:
The presence of sharp diurnal fluctuations;
the offer of coolness and high humidity;
Use of infected seeds;
The presence of soil-unfavorable soil.
Along with this, errors in plant care lead to the appearance of late bugs on cucumbers:
Excessive watering of the plants and, as a result, covering the soil under the plants with water;
use of watering from a hose, which leads to the spread of disease of sick bushes to healthy ones by water waste;
Mistakes in the preservation of earned fruits (lack of ventilation and moisture during storage);
Placing plantings in shady places;
Uncovered and not dug up according to the fruit, which left diseased cucumbers;
Lack of preemergence – depleted soil reduces the level of immunity of vegetables;
Violations of the microclimate of the greenhouse.
It is not recommended to use sick plants for compositions. Because of the high resistance of fungi to cold and heat, grass rot can be provoked in their plots. If affected bushes and their roots are not removed from plots in time, it happens that in windy weather they begin to break and fall to the floor, and then with rain penetrate into deep layers of soil. Together with them phytophthora penetrates into the ground. For further use of such areas, it is necessary to carry out reclamation and disinfection.
What to treat with?
Relevant topic in the fight against grass rot is the early detection of the disease – it is easier to treat in the early stages. Therefore, it is necessary to carefully monitor the growth of plants.
Often the disease can be recognized so early that treatment is carried out by elementary pruning of affected leaves and a simple planting treatment. In more advanced cases, Phytophthora should be treated in a variety of ways.
Before you start treatment, you need to make sure that the diagnosis is correct. Then choose the means (methods) to combat the fungus. The vegetative stage of the plants, their intended purpose and the personal preferences of the gardener are under the factors of such a choice.
Chemical preparations are quite effective in the treatment of grass rot, in some cases they can rid the greenhouse of the disease. Among them, for example, Bordeaux mixture. The main thing is to observe the correct proportions. In case of an excessive concentration of the composition, plant burns are possible. To prepare a working solution, use:
20 ml of 0.5% Bordeaux mixture;
Spraying of bushes is made in the evening. The process is repeated after 15 days. A 1% liquid is used, which is diluted in 4 liters of water.
If there is no improvement after the procedure, it is carried out again. Such procedures are continued with the same intervals until all signs of the disease disappear. Used solutions shall not be stored and used completely at once.
Copper-containing compositions (copper oxychloride) are effective against phytophthora. Such products help to destroy it quickly. In this sense, their use is productive:
After the application of chemical preparations, a period of 1 month should be sustained. It is dangerous to consume the fruit until the end. When treating plants, it is important to accurately follow the instructions on the package of these or those preparations. When treating, it is useful to water plants with solutions of a number of other ready-made preparations:
These preparations are at the base of poisons, which should be considered when using masks and gloves.
If the disease cannot be eliminated chemically, you can use systemic preparations containing special bacteria that are useful for plants, but spores. Among them, for example, “Trichodermin” and “Phytosporin”. Concentrates for treatment are made on their own, and then diluted in water in the required proportions and sprayed on bushes every 14 days. These productive and harmless preparations are also used as preventive agents.
For the treatment of infected bushes, the usual “Furacilin” (1 tablet per liter of water), whose solution is sprayed on the plants, is also effectively used.
The safest way is folk remedies – garlic infusion, formic acid, milk and some dairy products, yeast, “metronidazole” and so on. They usually show their greatest effectiveness in the early stages of the disease.
100 g of crushed cloves and leaves of the plant pour 10 liters of water;
insist for 24 hours;
The solution is strained and 2 ml of manganese is added.
Cucumber plants are sprayed with the prepared product before flowering of plants. The next spraying is carried out after 10 days. And the next – every 14 days.
If the first signs of the disease are detected, a remedy created on the basis of yeast is considered effective. In the first stage, a yeast infusion is prepared during the day, including 100 g of pellets and 10 liters of water. Then about 30 ml of iodine is added.
The use of wood ash is reduced when rooting seedlings in greenhouses and for the flowering process. The remedy contains 10 l of water and about 500 g of ash. The solution is infused for 3 days, stirring constantly. After 3 days, add 20 liters of water and about 40 g of crushed laundry soap for better adhesion. Spraying is carried out 2-3 times per season.
To stop the progression of the disease, treatment with a solution of table salt, which creates a protective layer on the leaves, preventing the penetration of fungi into the tissues of the plant. The working mixture includes 10 liters of water and 250 g of salt. The mixture is thoroughly mixed before use.
Kefir plants are treated in greenhouses in 7 days after planting seedlings. In addition, the procedure is repeated every 7 days. The solution consists of 10 liters of water and 1 liter of kefir. It is left for 48 hours to activate the fermentation process. Before the procedure, the working composition is thoroughly mixed.
Usually formulations based on whey are used, which are applied weekly. To prepare the product requires:
1 liter of whey per 10 liters of water;
Influence the solution for 48 hours until the appearance of light foam.
This composition is intensively stirred and sprayed them seedbeds. The remedy not only counteracts the emergence of late blight snake, but also scares away greenhouse and other pests.
Here they use methods of treating the leaves, as well as watering the bushes under the root.
“Metronidazole” (“Trichopol”) is an antibacterial agent, which perfectly repels insects and productively considers various infections. It is especially productive against late foliage and hoarding (15-20 tablets of “Trichopol” per 10 liters of water). Apply it fresh, spraying the bushes from the second decade of June.
Methods of treatment of bushes in the fight against late blotch are generally universal, except for some peculiarities.
In the open ground.
Similar treatment of bushes is carried out and in the open ground. It should be remembered that the procedures associated with care and treatment should be carried out on windless and dry days.
Spraying and priming cucumbers with compounds is better in the early morning or late evening with compounds. Water for watering should be at room temperature.
In the greenhouse
Cucumbers in greenhouses are treated on sunny, dry days, with open windows to ventilate the rooms. The inflow of fresh air flows is extremely relevant, otherwise the humidity will become too high, which is favorable for the development of the disease. After airing, plants can be sprayed with the selected product. If irrigation is planned, it is recommended to water under each bush with 2 spoon treatments.
In order to grow cucumbers painlessly in the future, it is recommended to soak the seeds in a solution of succinic acid or manganese for a few hours. Subsequently, one of the solutions for sprouts is also used, with which each bush is gently sprayed.
Preventive protection of plants from late beetles is provided by a number of obligatory preventive measures, starting a few weeks before planting seedlings from spring.
The floor should be watered with a solution of copper sulfate.
Repeatedly water the soil, now already “Phytosporin” (1 tbsp. product per 5 liters of water).
Planting varieties resistant to late blotch is possible and productive.
It is useful to plant onion and garlic plants next to cucumber beds, this will neutralize pathogens.
And you should also persistently and carefully avoid irregularities in care, these should be:
Watering the bushes on the upper layers of soil, which leads to stagnant water;
Avoid overgrowth of the plantings;
Regularly tilling beds and destroying weeds;
Do not weed the floor.
It is important to ventilate the greenhouse systematically and not to allow moisture retention.
Periodically loosen the soil and let it breathe well.
Feed the bushes, maintaining a balance of macro- and micronutrients;
In the fall, remove all residues of previous plants that have become infected and have rotting fruit with pathogenic spores.
Phytophthora on cucumbers and peppers. Methods of control. Disease resistant varieties
The development of phytophthora on cucumbers and peppers occurs gradually, and at first it is even difficult to identify this disease. And when the fungus approached the harvest, it is already difficult to change anything. Therefore, experienced gardeners recommend taking preventive measures to prevent the dangerous disease.
Phytopenia is caused by the fungus Phytophthora infestans, which reproduces asexually. The spores survive temperature changes and winter in the soil very well, and with the onset of steady heat of +17-+25 degrees quickly proliferate. High humidity promotes good fungal mold development, so strong phytophthora outbreaks are observed after rains.
Signs of phytophthora on cucumbers and peppers
Phytophora begins to actively appear in late summer. It looks like brown rotten spots on the leaves and stems. If no treatment is applied, the brown spots will begin to cover the fruits.
Picture of phytopsia on cucumber
Photo: Phytopsy on pepper
Phytophthora looks like a brown rot that first affects the lower tier of leaves and then climbs up the stem to the fruit. Affected leaves scare and dry out, so gardeners often overlook this problem, confusing it with a lack of watering. And herein lies the main problem, because with increased watering the humidity increases, which in turn contributes to the development of scab.
Causes of the development of late absenteeism
Even if the treatment of phytophthora was successful, if you do not eliminate the causes for which the active spread begins, it will appear again the following year. The main causes are:
- Closed arrangement of bushes and, as a consequence, disruption of free air movement;
- The neighborhood with potatoes or tomatoes;
- Lack of heat and changes in night and daytime temperatures;
- Increased rainfall;
- Excess fertilizer with nitrogenous substances;
- Excess lime in the soil;
- Watering not under the bush, but on the leaves;
- Lack of useful micronutrients, resulting in weak immunity in plants.
Prevention of Phytophthora
Preventive measures take some time, but it is better to spend it preventing the disease than trying to protect a rotting crop. The first thing to do if a late blight is found in your area is to destroy all diseased leaves and stems after harvesting. The best thing to do is to burn them. Material that supported the bushes (wire, stakes, ropes) either recycle or burn.
Water only under the bush. If you water over the leaves, the spores get better into the plant’s stomata. Excessive watering is also not necessary, as high humidity promotes the development of fungus. This also applies to seedlings in the greenhouse. It should be noted that the greenhouse especially needs good ventilation, because the air in it is susceptible to high humidity.
Soda or soda solutions are also used as bait. Soda has an antibacterial effect on fungi, and plants become more resistant to attacks by various fungal diseases.
Late blight control methods
The use of fungicides is the main measure to combat late blight in the active stage, in which most of the system is affected. They are effective on the focus of infection and destroy the spores of the fungus. Their use can be limited because they contain toxic substances that can accumulate in the fruit. And this, in turn, is very harmful to humans. The processing procedure itself also requires attention and full compliance with safety measures. Be sure to protect the skin and try to avoid contact of chemicals with the mucous membranes. When preparing all compounds, strictly follow the proportions and adhere to the descriptions, because a small amount of the substance may not work, and abuse is fraught with negative consequences.
Samples that go to seedlings are soaked in a weak solution of potassium culprits. Then they are watered into the ground after planting, when the seedlings are strong enough and put down roots.
For the treatment of cucumbers and peppers are suitable drugs Arzedil (50 g per 10 liters of water), Ridomil RC (25 g per 10 liters) and Oksihom (20 g per 10 liters). To spray the leaves use Dietamine (20 g per 10 liters of water), Phytosporin (10 g per 10 liters), copper chloride (40 g per 10 liters of water) and Damp (25 g per 10 liters). Copper sulfate, burgundy or pergonate potassium solution also have a positive effect.
Application of furatilin is a simple and effective way to get rid of phytosporosis. The solution is made at the rate of 10 tablets of furatilin per 10 liters of water. Spraying is carried out three times: before flowering, at the appearance of the first ovaries and at the beginning of lodging of cucumber or pepper.
Description of folk remedies
Folk remedies are well-proven, the advantage of which is the safety of their use for humans. They are less effective in the late stage of the disease, but if you start using them, you can get rid of late insufficiency. Countries can be treated with the following folk remedies:
- Garlic solution is prepared from 10 g of garlic and 10 liters. Water. The composition should be boiled for a day, then strain and spray. Sometimes potency is added.
- Sour milk and kefir are loosened in water (1 l per 10 liters). Infuse for several hours, strain and spray.
- Boil 100 g of bittercress in one liter of water and boil for 30 minutes. After cooling and filtering in 5 liters of water and treat the bushes.
- For 10 liters of water take 1 kg. Hay and a handful of urea. Give 3 days every 2 weeks and treat the plants.
- An effective remedy is also an infusion of trutovik mushroom. It is poured and boiled.
- To keep phytophthora from spreading so much under cucumber bushes and cover the wood in rows.
Many of the varieties listed below are resistant not only to disease but also to low temperatures:
- Broken Man;
The earliest cucumber varieties resistant to late scab:
- Prima Donna Cornichon.
Medium cucumber varieties:
- Goose Pulp;
- Phoenix Plus;
I always carry out preventive measures to avoid the appearance of a late post. I use only folk remedies, because I do not want to poison my family with chemicals. I fertilize with phosphorus-potassium fertilizers. I sprinkle seedbeds with ashes. I soak cucumber and pepper seeds in potassium dressing and take only resistant varieties.
Phytophthora destroyed my crop of cucumbers, they looked terrible, so since autumn I take preventive measures. I read a lot of reviews on the Internet and started to follow a certain technique. I burned all the plants and sprayed with furalin. Then in the spring I also conducted an additional treatment. Be sure to feed useful fertilizers that increase the immunity of plants.