What to do if cucumber seedlings turn yellow leaves?

Cucumbers - one of the fastest growing and less capricious agricultural crops, which can be grown even in a small apartment. Despite the speed of emergence of cucumber seeds and the relative unpretentiousness in cultivation, seedlings and adults lash are susceptible to various types of diseases, which are primarily manifested in the form of yellowing leaves. To collect a tasty crop of cucumbers, it is necessary to look at the plants, in time to identify the causes of yellowing and take action.

The reasons for the yellowing of cucumber seedlings can be various factors. When determining the cause of the deterioration of the green cucumber shoot, the place of growth should be considered:

• in the greenhouse;
• at home (in the living room on the windowsill);
• in open ground.

The reasons for the appearance of yellow spots on the leaves or the trunk of the cucumber in the greenhouse may be the following factors:

• Bad airing. Cucumber seedlings grow rapidly, which complicates the process of airing the rows. On the other hand, excessive drafts, sharp gusts of wind also adversely affect the leaves and the crop as a whole. Since cucumber seedlings are a very thermophilic culture, drafts can not only provoke a sharp overcooling, but also deform a fragile plant.
• Rapid drying of the soil. With the active sun under a film or glass, the moisture evaporates very quickly, the soil dries out much faster than in the open air. Dense crust, which is formed from the drying of the soil, does not give full breathe to the root system of the plant.
• Excessive watering. Together with insufficient airing and thick transplanting, moisture is retained in the upper layers of the soil. When excessive moisture creates a greenhouse effect, the roots can rot, so that the leaves may turn yellow, the trunk of the lash covered with yellow spots.
• Watering with cold running water. It creates a sharp temperature drop, since the temperature of the air and soil in the greenhouse is higher.

Causes of disease of cucumber seedlings in the open field, which also apply to seedlings in the greenhouse:

• Unsuitable soil composition. When planting cucumber seedlings at the same place, the qualitative composition of the soil is significantly depleted. During the downtime in the autumn-winter period, the earth does not have time to restore the qualitative composition due to lack of fertilizers.
• Root rotwhich strikes a plant from a stalk, and then passes to leaves. Root rot is caused by excessive watering and / or watering by unsupported cold water, as well as untimely loosening of the soil after each watering.
• Sharp temperature drops. In pursuit of an early harvest, cucumber seedlings are planted in the spring in the greenhouse ground or in the open air. It is the early spring that is dangerous for thermophilic seedlings by large temperature drops during the day and at night, as well as by frosts.
• Burns Top watering with cold water and the remains of droplets on the leaves of seedlings leads to sunburn of leaves. They can also be obtained from direct sunlight or from harsh cold temperatures in the form of frosts.

• Poor quality planting material. Improper storage of seeds, expired storage of planting material is one of the common causes of seedling disease.
• Tying lashes. Depending on the type of cucumber, plants should be tied up and the lash should be allowed to grow on a support (stretched cord or twig). Prolonged contact with the lash of the earth will provoke yellowing of the leaves and slow down the growth of the plant. At the same time, varieties of cucumbers are used on open ground and large areas, which, on the contrary, should be left to follow along the ground.
• Viruses, pests, pathogens.

The above reasons provoke yellowing of leaves in any place of growth. Selected reasons should be disclosed in more detail.In case of poor soil, the yellowing of seedlings is caused by the absence of necessary trace elements. Overabundance or shortage of individual trace elements can be determined by the localization of the lesion of the stem and leaves of cucumber seedlings. Yellowing of the lower part of the lash indicates a lack of phosphorus and magnesium, yellowed upper leaves indicate a lack of zinc, iron, manganese, a thinned stem and pale leaf color indicate a lack of potassium.

Viruses, pests and diseases affect the leaves of seedlings with peculiar traces that need to be deciphered to determine the diagnosis and correct treatment. The disease of heat-loving plants, such as powdery mildew, is quite common. This disease is triggered by an excess of moisture, which contributes to the development of the fungal strain. Manifested in the form of twisting the leaves into a tube and the loss of brightness of the color of the plant.

Common spiders for cucumber seedlings are spider mites and melon aphids. The spider mite envelops the leaves of the plant with a thin web like a cocoon, under which the leaf color seems to burn out, and the leaf itself is covered with yellow streaks.

Gourd aphid, devouring the edges of the leaves, causing significant damage to greenery. Leaves and stems are not only injured, but also dry out dramatically. Fusarium disease is the most ruthless disease and difficult to fight for cucumber seedlings. The fungus infects plants from the base. Damage is manifested in the form of drying of the stem and leaves.

Residents of megacities in pursuit of organic products, or those who do not have the opportunity to grow seedlings in a greenhouse or in the country, resort to growing cucumbers in a house on a windowsill.

The reasons for the yellowing of cucumber seedlings at home can be:

• Lack of coverage. On the windowsill pots with seedlings can overlap each other, hiding the sun's rays. Lighting daylight is also small, especially in the northern regions of our country or in early spring, when daylight is still short.
• Direct sunlight. Unprotected young shoots are very delicate, and the sun's direct rays even under the refraction from glass can cause irreparable burns to plants.
• Poor dimensions of the pots or boxes for seedlings. In cramped pots, the root system does not receive sufficient irrigation or may rot, which causes yellowing of the leaves and also complicates the process of ventilation of the root system.
• Unsuitable soil for cucumber seedlings. An excess or lack of certain trace elements provokes the appearance of yellow spots on the leaves and stalks of seedlings, slowing the growth process.

If yellow spots appeared on the cucumber seedlings, this may be due to a combination of the above reasons. Despite demanding care, cucumber seedlings can be saved by providing timely identification of the causes of the disease, as well as using a set of measures and processing plants with special means and solutions.

At the initial detection of yellow spots on the leaves should immediately identify the causes of the disease and take a set of measures. Timely struggle with yellowing of seedlings can prevent the spread of infection to other shoots, save plants and get the desired yield.

At the initial stage of germination of seedbed seedlings, the first dull or yellowed leaves can appear immediately. At this stage, it is worth checking the planting material. This test should be done exclusively from the seeds of one batch. A few seeds from the package are poured with water for 2-4 hours and watch how quickly the seeds settle to the bottom. If the seeds remain on the surface of the water, the planting material was stored in violation of the conditions or the storage period has expired.

If it is noticed that the edges of the leaves are drying or the stem of the lash itself, it is necessary to identify the cause and take immediate action.

First of all, it is necessary to organize high-quality ventilation in the greenhouse, which will exclude harsh gusts of wind and direct sunlight on the seedlings. It is better to provide in the greenhouse a system of opening and closing the flaps on the roof and in the walls. There should be a sufficient amount of ventilation flaps so that there are no unventilated areas.

Thinning between rows. In order to avoid silting of the soil and accumulation of excessive moisture, the distance between the lashes should be spacious enough so that air flow can air each plant.

Maintaining the required temperature in the greenhouse is very important. Especially in sunny weather, one should not allow overheating of the seedlings, for this purpose it is necessary to open and close the valves for ventilation in time. Excessive solar activity can be reduced by stretching the agrofabric over the seedlings or by using any canvas to darken.

Cucumber seedlings require not only an optimal thermal regime, but also lighting more than 10 hours a day. To compensate for the lack of sunlight during daylight hours should be equipped with additional lighting lamps.

Depending on the location of the lesion of the stems and leaves, it is necessary to select a complex of mineral fertilizers. It is necessary to carry out top dressing strictly according to the instruction in order to avoid soil oversaturation with fertilizers.

Pest control should be carried out using special solutions and tools. The most common means for pest control is a solution of household soap, which should handle the leaves on both sides and the stem. Do not forget about the edges of young leaves that have not yet been affected by the pest. The soap solution is safe for use indoors.

The fight against the defeat of seedlings in the open field involves the use of Additional methods other than those used in the greenhouse:

• Stretching agrofabric over young cucumber plants will help prevent leaves from curling and yellowing of the tips of young leaves from direct sunlight, as well as protect them from unexpected frosts. The fabric in the open space should be stretched on the arc or metal frame, pre-built over the entire perimeter of the growth of cucumber seedlings.
• The alternation of the place of planting cucumber seedlings. This method should be used especially in small personal plots in order to provide a sufficient amount of nutrients in the soil needed for cucumber seedlings.

• Top dressing plants with mineral fertilizers.
• Watering plants and loosening the soil to ensure aeration of the root system and avoid overwetting the soil.
• The fight against plants affected by fungal diseases in the open field is very difficult. With the rapid spread of the fungal disease, treatment with Bordeaux mortar may be ineffective. In the open air, spraying with 1% potassium permanganate solution or onion extract can be applied. If the damage to seedlings is progressing, a radical method is taken: the plants are removed by the root, and the soil is treated with an antifungal solution.

If all of the above means do not bring results and the leaves continue to turn yellow, and the plant withers, most likely there is a viral disease. It spreads very quickly through all the plants in the garden, so the only solution would be to remove infected plants and burn them or destroy them outside the garden. After the removal of infected plants, the soil is treated with an antifungal solution and allowed to rest for a year.

Correctly determined reason and timely measures taken to combat the yellowed seedlings or leaves of an already grown plant are, in most cases, effective and will help to maintain a high yield.

It is much easier to protect seedlings from infection than to save adult plants from yellowing on the leaves and stems. The complex of measures for the prevention of yellowing of cucumber seedlings after planting is a systematic sequential action that must be carried out throughout the entire life cycle of the plant.

Preventive measures are suitable for cucumber seedlings both in the greenhouse and in the open field:

• Before sowing, it is necessary to check the seeds for germination (germinate the seeds in a warm, humid place). To prevent fungal diseases, you can soak the seeds in a weak solution of potassium permanganate.
• Every year it is necessary to change the place for planting cucumber seedlings. This is especially true if last year the seedlings were affected by a fungal disease.
• Before planting it is necessary to fertilize the soil with mineral fertilizers, treat the walls of the greenhouse with an antifungal solution.
• Observe the distance between the plants with regard to their growth. Each whip cucumber seedlings should be planted at a distance of 25-30 cm from each other, subject to tying this variety. For cucumbers that spread along the ground, the distance between the bushes of the plant is about one meter.

• At the initial stage of growth, transplanted seedlings should be watered with settled water. Also prepare an infusion of water with the addition of bread. This nutrient fluid promotes rapid growth.
• Growing plants before detecting any yellowing and diseases, it is better to immediately treat with a solution of soap. It is also recommended to use a solution of water (10 l), milk (1 l) and iodine (1 vial). These types of treatment will not save from sunburn, but will prevent the appearance of pathogenic microorganisms, fungal infections.
• Organization of continuous ventilation of the lash and root system. In the greenhouse it is necessary to constantly open and close the valves for airing, to monitor the temperature regime. On open ground and in the greenhouse after each irrigation, after 10-12 hours, loosen the soil.
• Shading seedlings from aggressive sunlight. In the greenhouse and in the open field is ideal for this agrofabric. It helps to dissipate the sun's rays, at the same time transmits ultraviolet light.

• At the initial stage of active growth, as well as during the cucumber ovary, it is necessary to feed actively growing plants with fertilizers with a complex of minerals, taking into account the composition of the soil.
• To fight and excess moisture, the top layer of soil should be covered with wood ash. If not, you can use river sand.
• In the greenhouse and on the windowsill special attention should be paid to additional means of lighting. For this fit fluorescent lamps or ordinary incandescent lamps. When using the latter, it is necessary to ensure that they do not get burns on the leaves.

About why cucumber seedlings turn yellow leaves and how to deal with this, see the next video.