Diseases of seedlings of cucumbers and their treatment
Diseases of cucumber seedlings cause a lot of trouble to summer residents, leading to the death of young companies at the stage of their initial development. Timely measures taken help to save the seedlings and save them for future planting in a greenhouse or open ground.
Diseases of seedlings of cucumbers and their treatment
The main causes of yellowed foliage of cucumber sprouts are fungal pathogens and pests. However, among other causes of yellowing of seedlings, sometimes improper care for cucumbers also becomes:
- tightness and lack of space - actively growing cucumber bushes require a lot of space every day, and the root system requires more mineral nutrition,
- lack of sufficient fertilizing, especially nitrogen, potassium and magnesium, leads to the fact that the seedlings begin to hurt,
- Inadequate lighting, or vice versa, the installation of a container with planted cucumbers in places with direct access to the sun leads to yellowness of leaf blades of cucumber sprouts.
Comprehensive care of cucumber seedlings can prevent the development of the disease of yellowed leaves.
It is possible to fill the deficiency of microelements by applying fertilizers and top dressing. Among the fertilizing complexes are Vermistim and Azogran. With a lack of potassium, watering with ash infusions helps. Yellow leaves respond well to onion infusions, which are made from 50g of onion husks with 10 liters of water, boiled, cooled and filtered cucumber plantings are watered with a strained warm working solution.
At the stage of formation of the root system in young shoots, it is required to transplant seedlings in a tank larger in size. A pick is done when the first 2-4 leaves appear.
Fusarium and verticillin wilt of young seedlings of cucumbers is often associated with damage to plants by soil fungus that penetrates the root system and destroys the sprouts from the inside. As a result, the growth and development of cucumber culture is suspended. Initially, the upper part of the seedling withers with a loss of elasticity, but in some cases a pathogenic fungus causes the death of the whole plant as a whole. It is possible to detect the presence of fungus on the root cut in the form of brown rings.
Favorable conditions for the development of a pathogenic fungus leading to Fusarium wilt are dry air and a temperature rise of up to 25 ° C-28 ° C, while verticillosis wilt requires high humidity and a temperature of no higher than 16 ° C-20 ° C.
Decontamination of soil and thorough cleaning of beds from past plant residues when seedlings are planted in a greenhouse helps to cope with withered foliage and prevent the death of plants. Phytosporin, planriz and trichodermin help get rid of the pathogenic fungus. These drugs water the soil 7 days before the planting of seed material or seedlings.
Fighting the disease
Improper care of cucumber plantings often leads to the fact that the seedlings of cucumbers are rotten, after which the seedlings die.
Gray rot appears with excess moisture and due to irrigation of seedlings with cold water in the conditions of too dense plantings of cucumber bushes. Among the initial signs - a slippery coating of gray, covered with gray fluff.
In the fight against gray rot helps:
- ventilation of the greenhouse when seedlings are grown indoors,
- the termination of watering for 2-3 days,
- cutting off damaged parts with dusting of sections with ash or chalk powder,
- removal of diseased seedlings and spraying of the remaining healthy with phytosporin, oxychoma, trichodermin with extensive damage.
When seedlings become diseased with root rot, their root system becomes brown, then the root neck becomes too thin, dries and dies. As a result, the plant dies.
The causes of root rot can be a violation of the rules for watering seedlings, sharp temperature drops, an overly deep planting of seed material and an overly dense planting of sprouts.
At the first signs of measles rot, the earth is scooped up from the stems, the root system is treated with disinfectant solutions. As a treatment for disinfection, a mixture of 2-3 large tablespoons of copper sulfate, 6 large beds of fly ash or limestone per liter volume of water is effective.
The roots of seedlings are sprinkled back with earth only after they have completely dried out after disinfecting treatment.
The fungal disease of cucumber seedlings shows a black leg in plants in the form of black formations in the area of the base of the stem. The fungal pathogen clogs blood vessels and becomes a barrier to the supply of mineral nutrition to the roots. As a result, cucumber seedlings die, bending to the surface of the earth.
We determine the disease
Among the main reasons for the appearance of a black leg are the density of landings, disturbance of illumination and sharp temperature drops.
Preliminary sterilization of the soil mixture helps to prevent the development of black leg fungus in the soil. Before use, it is steamed in the oven, after which it is treated with a disinfectant solution for 2–3 hours. Ash powder or sand is mixed into the soil before planting the seeds. Trichocin, Previkur and Gliokladin helps as a disinfectant.
Cucumber mosaics can have several varieties, but all of their pathogens are carried by insects, often aphids and whiteflies. In some cases, the cause of the cucumber mosaic is an infected seed. With a mosaic disease of cucumber seedlings, the photo shows an unusual pattern on the foliage of cucumber seedlings.
Field mosaic on cucumbers brings aphids. Field mosaic viruses persist throughout the winter in the roots of weeds. As a result of the disease, the foliage of the seedlings is covered with a yellow-green mosaic pattern. Subsequently, the infected leaves begin to curl, dry out and fall off after a while. Seedlings weaken and with a decrease in heat stop their growth and die.
In order to prevent field mosaics, serum is sprayed with a concentration of 50%, diluted with water 1: 1 or phytosporin.
White and green
With a white mosaic, the foliage of a cucumber culture is covered with white with a yellow tint spots, merging into a single large spot, with a green one the wrinkles and become light spotted. The reasons for the white and green mosaic, transmitted through infected seed material, soil and plant debris, are a sharp drop to 30 ° C and above.
Against a white and green mosaic, the seed material is preheated and pickled before planting. Sick seedlings are sprayed with serum, removing damaged sprouts.
Powdery mildew on cucumbers usually develops in closed greenhouses. Its fungus initially settles on the foliage of cucumber seedlings, subsequently moving to all other parts of the plants. As a result, seedlings begin to noticeably lag behind in their development.
The reasons for the appearance of powdery mildew are irregular irrigation, a saturation of the soil with nitrogen and a lack of potassium in the ground.
Field horsetail and marigold have a detrimental effect on powdery mildew, from which they make infusions for watering affected seedlings. For the treatment of fungal disease, fungicidal preparations containing Bordeaux fluid, copper and iron are used. The foliage of cucumber seedlings is treated on both sides, with repeated spraying a week later.
Powdery mildew has some other signs, appearing on the outer side of the leaf blade in the form of oily yellow spots along the central leaf vein, and on the inside - in the form of a gray sporous plaque. As a result, the leaves become dark in color, their tissue is destroyed.
To prevent the disease with downy mildew, the seed material is disinfected with zinc sulfate heated to 50 ° C. Among the folk remedies for treating peronosporosis are whey, a solution with mullein, and soap-soda liquids.