Diseases of cucumbers in the greenhouse and their treatment
Growing any kind of cucumber in a greenhouse requires some skill. Either empty ovaries will be tied up, then diseases or pests will attack, or cold dew will settle on the leaves. To understand why this or that attack occurs, you need to be able to see the disease on the plant and treat it in time. Prevention is even more important, when gardeners do not wait for rot or pests to appear on cucumbers, but they themselves proactively organize protective measures.
Cucumber diseases and treatments
Diseases of cucumber plantings inside greenhouses are divided into viral, fungal and bacterial. Each of them has its own pronounced signs, due to which the disease can be "calculated". Often, spores and fungi in the greenhouse are carried by aphids and other harmful creatures.
Why is the infection of more recently healthy plantings occurring? There are general principles, violation of which contributes to the spread of cucumber diseases.
Violations of agricultural practices that contribute to the development of diseases:
- Sharp fluctuations in temperature values.
- The air humidity is higher than the seasonal standard values.
- Planting cucumbers after crops that are categorically unsuitable as predecessors.
- Poorly organized lighting.
- Through ventilation of the greenhouse.
- Spraying water over the leaves of the cucumber.
- Watering with cold water, in addition to diseases, gives crooked cucumbers.
- Scarcity of nutrients in the soil.
- Incorrect feeding of cucumber in the greenhouse.
- Untimely removal of diseased specimens.
- A wasteland left on the lashes.
- Lack of disinfection in the space where diseased bushes grew.
What's important maketo maintain healthy plantings:
- Observe the crop rotation in the greenhouse.
- Use healthy seeds.
- If necessary, soak them in a weak manganese solution.
- Plant in warm soil. At least 12 degrees in the deepened soil layer of the greenhouse.
- Disinfect soil, tools and indoor greenhouse space before planting a cucumber.
- Maintain night temperatures in the greenhouse at least 17 degrees Celsius, during the day not higher than 30.
- Destroy plant debris.
- Tightly seal all joints and crevices inside the greenhouse.
- Carry out preventive treatments.
- Fertilizer for cucumbers in a greenhouse should not exceed dosages per 10 liters of water: carbamide 6-12 g, superphosphate up to 10 g, ammonium nitrate up to 6 g, potassium chloride 8 g. curves will grow.
- Dig deep into the soil in the fall.
Observing the rules of agricultural technology, any diseases can be "caught" at the initial stage, which means that you do not worry about the question of why this happened, but simply effectively treat them or reduce the tragic consequences for the crop in the greenhouse.
Viral infections
Viral diseases of cucumbers in the greenhouse are considered the most dangerous. Why are the "borage" so afraid of them? It turns out that the treatment of viruses is problematic in principle and the best way to protect yourself is preventive measures, the choice of varieties that do not get sick, high-quality thinning and total destruction of infected bushes.
Cucumber mosaic
Usually, the disease manifests itself when the cucumbers grow for no more than a month. The leaves acquire chlorotic marble spots, which gradually turn yellow, wrinkle, dry and become wart-like. There are few female inflorescences, the fruits of cucumbers from them grow poorly and acquire a salad color. Basically, the ovaries dry and crumble, some go into the barren flowers. White mosaic "paints" the plant in white and yellow star-shaped spots. Often, the stripes on the cucumbers turn white.
Routes of transmission of the virus: on the legs and wings of aphids and other small insects, through garden flowers (phlox, gladioli) or preserved plant debris, contaminated garden accessories. With white mosaic - only by seeds or by direct contact.
High temperatures accelerate the onset of the mosaic. With a decrease in heat, it is necessary to collect curved cucumber fruits.
If diseased cucumber plants are found, do not think for a long time why this happened. The best treatment is to immediately pull out the bushes and disinfect them. Otherwise, most of the crop dies.
Fungal
Diseases of the fungal pathology of cucumbers remain the most common. The disease is transmitted through plants inside the greenhouse by fungal microspores that cling to any part of the plant. Timely treatment is effective, but if the situation is not controlled, the plants in the greenhouse die up to 100%.
Anthracnose (copperhead)
Signs of a cucumber infestation: brownish-yellow oval specks on the leaves, which gradually die off and crumble . On the cucumbers, single sores or ulcers located in a group are buried. In humid weather, their surface is "covered" with a copper-pink bloom, gradually darkening, denser and blackening. Cucumbers acquire bitterness and are poorly stored. It is dangerous to eat them. Spores lurk in harvested seeds and green residues.
Treatment methods:
- Irrigation with copper sulfate in half with slaked lime, 1% concentration. Every week, ending 5 days before harvest.
- Cupritox.
Rot
In greenhouse conditions, cucumbers are especially attacked by rot of different colors and characteristics. The disease destroys the plant, develops barren flowers and, in general, leads to the death of the entire bush. Particularly contributing factors: excessive burial of seedlings and lack of nitrogen in the soil.
Rot types | Which part of the plant is affected | Signs of infection | Treatment methods | What to do for prevention? |
---|---|---|---|---|
White (sclerotinia) | The disease begins with leaves, covers peduncles, ovaries and fruits. Young plantings in the greenhouse die. | White bloom. First, cotton type, then turns into mucus. Fruits turn black and rot. | Cut the infected area of the cucumber with the capture of a healthy surface. Treat part of the cut and the entire bush with lime, copper sulfate or crushed coal. For treatment, spray with a solution of 10 g of carbamide in a bucket of water. | Observe the crop rotation in the greenhouse. Spill the planting sites with potassium permanganate (per 5 g bucket). Ventilate. Thinning. Barren flowers, the remains of bushes, rotten leaves and fruits to burn. The contaminated soil of the greenhouse should be disinfected annually with 2% potassium permanganate; in case of extensive damage, remove it to a depth of at least 15 cm. |
Gray | Originally - cucumber leaves and ovaries. | Gray rot appears as slippery brown spots that turn gray, become covered with black dots and merge. Especially in the axils of cucumber leaves and their branches. When the variant is neglected, rotting empty flowers (up to 15 on one sheet) are formed in a multitude, damaged ovaries disappear. | At the first sign, sprinkle the stems and leaves with chalk powder in half with copper as a treatment. Remove empty cucumber flowers, gently rub the slices with charcoal or ash. Sprinkle the places where rot has formed with a mixture: 1 teaspoon of sulfur-copper salt in a glass of ash. If the treatment does not help, burn the plant. | Activities similar to those organized for white rot. |
Root | The disease begins in the root zone. | Seedlings of cucumbers grow poorly, many rot kills instantly. Near the root, the stem turns yellow and cracks. Leaves wither, whips and ovaries of cucumbers dry up, empty flowers remain, roots die off. | Solution for 0.5 l of water: 1 small spoonful of copper sulfate or "Hom" preparation, 3 large tablespoons of honey or wood ash. Shake off the soil from the root, dip a brush into the solution, smear from the roots along the stem to a height of 12 cm. Where rot has appeared, powder it well with ground coal, chalk or ash, dry it. Spill the deepening after a sick bush with copper sulfate - stirring two tablespoons on a bucket. Disinfect the greenhouse soil with dry bleach - 200 g for each square meter. | To avoid illness - disinfect the greenhouse before planting seedlings. Add a mixture of decomposed peat, humus and turf. Warm up the seed material and pickle. Do not cover the stems during planting. Mulch the greenhouse soil with peat mixture, lime, sawdust or clean sand. Remove wasteland. Water in moderation on the ground, in the morning and with warm water. Do not add soil to the diseased stem or huddle. |
It is important not to water the plant if a disease appears on it. Infected plantings from the greenhouse must be burned.
Dew
Powdery mildew is a fungal infection of cucumbers that occurs in two types of disease.
Plain mealy
The disease manifests itself in the form of a white powdery coating. Then the pale leaves gradually turn yellow, actively dry out and the cucumber bush dies. Powdery mildew is carried by weeds, flowers, poorly disinfected soil or contaminated water.
Treatment recipes:
- A liter of liquid mullein and a large spoonful of urea are diluted in a bucket of warm water. Irrigate the leaves from below and from above.
- The dusty composition of sulfur is showered for treatment on those cucumbers where dew is found. 30 g for every 10 square meters.
- A solution of potassium permanganate - for a bucket of 1.5 g.
- The drug "Topaz" - before the flowering of the cucumber, then with the appearance of 7-10 leaves. Or when a disease is found.
- Other treatments as treatment: colloidal sulfur (80%) with the addition of laundry soap, Topsin (70%), Bayleton, etc.
It is advisable to process cucumber plantings in warm weather without wind, in the morning. Close the greenhouse.
Downy mildew (downy mildew)
At any stage of growth, cucumber downy mildew is widespread. Sources of the disease are "buried" in the greenhouse for up to 7 years.
Powdery mildew appears on the cucumber's leaf cover as oily spots, most often green. Their number is gradually increasing. The appearance of the burn appears, then the disease finally "finishes off" the planting - in three days the leaves twist and fall out. Downy mildew "grows" during temperature fluctuations, fogs, condensation on the film, using cold water for irrigation in a greenhouse.
Treatment regimen:
- Stop watering and feeding cucumbers for a week.
- After normalization of humidity, spray with "Topaz" or "Oxyhom" as a treatment. The solution is always warm.
- Can be thoroughly sprayed with "Fitosporin" and sprinkle with ash.
- Ventilate the greenhouse, but not colder than 23 degrees during the day and 18 at night.
- Of the simpler remedies for treatment, use copper sulfate in lime milk, cupritox, urea (1 g per liter). Do the processing of leaves on both sides.
Olive or brown spot (cladosporium)
External signs of the disease: brown or dark green soft ulcers, from which fluid is released, cover the fruits, sometimes cucumber leaves. They grow and harden quickly. The skins of the vegetables are cracking. For 6-8 days, the rot can completely "eat" the cucumbers. The disease is especially active at the end of summer. Infection is possible by airborne droplets.
What maketo slow down the disease:
- Stop watering cucumbers for 6 days.
- During warm periods, ventilate the greenhouse well.
- When it gets cold, keep the temperature at 23-25 degrees.
- Treat with copper oxychloride (0.4%), Bordeaux liquid (15%) or Oxyhom.
Any fungal infections of cucumbers are "lethal" by the preparations "Barrier" and "Zaslon" that are harmless to humans.
Bacteriosis (angular spotting)
It is unknown why, but this bacterial infection "eats" only cucumbers. At the cotyledon stage, dark green oil-type spots or sores grow between the leaves. Older plants, the disease affects spots of an angular shape between the veins of the leaves. If humidity rises, oily plaque and yellow rot "spreads" over the surface. Then the tissues dry up, die completely and fall out with the formation of holes. Dark wet ulcers grow on the cucumbers. Pest bacteria spread throughout the plant.
Drugs affecting the disease: Champion, Kuprox, Bordeaux liquid.
To prevent disease, cucumber seeds are soaked for 24 hours in 0.02% zinc sulfate solution before planting, dried and then planted.
Pests
The scourge of cucumber plantings in the greenhouse is not only diseases, but also pests. Most of all, cucumbers suffer from the pest of aphids and whiteflies.
Melon aphid
Insects with an average size of 2 mm, black or dark green, prefer to settle on the lower part of cucumber leaves and on whips. Aphid colonies suck bushes and carry viruses. Their hordes multiply rapidly and destroy cucumbers. The leaf cover wrinkles, curls and falls off.
The main source of aphids is weeds. Therefore, they must be removed promptly.
Folk recipes for destruction aphids :
- Pour 200 g of tobacco dust and 30 g of fresh capsicum on a bucket of hot water. Insist 24 hours, strain, add 3 large tablespoons of wood resin and 1 - liquid laundry soap. To treat aphids, spray the places where cucumbers grow and the path between the rows. Repeat in a week. Consumption of at least 2 liters per square meter.
- Stir 2 cups of ash and 1 large spoonful of laundry soap in a bucket of hot water. Insist for a day, stir, strain and spray the cucumbers.
Treatment chemicals:
- 50 g "Arrows" in a bucket of water or 1 tablet "Intavir" for the same volume. The drugs not only treat, but can also rejuvenate cucumbers in a peculiar way due to additional nutrients.
- For the usual volume of warm water, "charge" 2 tablespoons of karbofos. It is not enough to spray cucumber plants with them, the main thing is to process the air, paths, soil and even the roof, so that there is a “calm” place for the aphids. As a treatment, the procedure is carried out in sunny weather in a completely closed greenhouse. On the plants themselves, the concentration of the drug should be 2 times less. Especially carefully handle the cucumber plants from below. Do not open the greenhouse for an hour, then very carefully loosen the ground to a depth of 2 cm.
Whitefly
Small insect with white wings. The pests suck the juices from the bush and secrete a sugar liquid, which is seeded by the fungus. After that, the cucumbers do not grow long, turn black and die.
Prevention: destroy weeds, cover openings for ventilation with gauze, place traps for adhesion. Spray with Aktofit three times a season (0.2%).
For treatment, it is good to rinse the lower part of the leaves of diseased cucumber bushes with clean water, then loosen the soil, sprinkle sawdust with a layer of up to 2 cm. The sawdust should not be fresh for 1 year.
Knowing why empty ovaries are tied or crooked cucumbers grow, what drugs to use for aphids, or how to cure rot on the bushes, vegetable growers will not be left alone with their problems. When a disease or pest is known "in person", it is easier and faster to fight them. If you add effective prevention to this, the chance to get an excellent harvest of cucumbers in the greenhouse is significantly increased!