Hollow cucumbers: causes and treatment

Sometimes, after harvesting cucumbers, vegetable growers discover that some of the fruits are hollow. Hollowness is associated with problems in the formation and development of the vegetable. The causes of hollowness vary, including agricultural errors, unfavorable climatic conditions, and diseases. In some cucumber varieties, hollowness is related to varietal characteristics. If detected early, the problem can be easily corrected by adjusting the growing conditions.

Reasons for the appearance of voids in cucumbers

You can tell if cucumbers are hollow by their appearance. The surface of hollow cucumbers is wrinkled and slightly concave. Hollow cucumbers weigh much less than expected. You can finally confirm the presence of hollow spots by cutting the fruit open.

The quality of the ripened crop is affected by many external factors. But the most important one is improper vegetable care. Incorrect watering, nutrient deficiencies, and poor adaptation to soil and climate conditions disrupt the development of the placenta, which contains the seed primordia.

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Unsuitable microclimate

Empty spaces inside the fruit often form when cucumbers are grown in greenhouses. The vegetable does not tolerate sudden temperature fluctuations, which are common in different regions of the country. In summer, the difference between daytime heat and nighttime coolness can reach 10-15 degrees Celsius. For most varieties, such temperatures are detrimental.

For active fruiting, cucumbers require the right light conditions. Leaves develop in bright sunlight. However, once fruiting begins, plants need shade during particularly hot hours. Insufficient sunlight causes cavities to form inside the cucumbers, making them small and tasteless.

Varietal characteristics

Breeders have now developed varieties of this vegetable that are less prone to developing hollow fruit. This characteristic is typically found in hybrids labeled F1 on the packaging. Varieties that are less prone to hollow fruit include:

• Green Wave;
• Maryina Roshcha;
• Buyan;
• Clean ponds;
• Grasshopper.

The only drawback of hybrids is their inability to pass on their traits to subsequent generations. Therefore, seed from such varieties is not collected independently; instead, new seeds are purchased annually. This reduces the risk of fruit hollowing.

Watering

Most vegetable growers are sure that cucumbers the bushes need to be watered As often as possible. This statement is partly true. A plant is 90% water. A lack of moisture reduces the plant's ability to absorb nutrients from the soil, and it stops growing. Excess water in the garden is also harmful. Excess moisture causes plant tissue to crack and roots to dry out. The cucumbers' weight decreases, and hollow spaces form.

Cucumbers are watered in the morning or late evening, when there is no direct sunlight. Otherwise, leaf burn is likely. Water moderately, as recommended by the seed manufacturer. Plant roots are located in the surface layer of the soil. Therefore, when the soil dries out, they cannot absorb nutrients and develop normally. During the period of active growth and fruiting, water the plants daily. During flowering, reduce the frequency of watering.

To reduce moisture evaporation and the need for watering, the soil is regularly loosened or covered with a layer of organic mulch. As it decomposes, it acts as a fertilizer, enriching the soil with nutrients and improving its structure.

Nutritional deficiencies

A lack of nutrients slows the development of cucumbers. As a result, fruit quality deteriorates, and cavities appear. To create a favorable environment, a mixture of organic and mineral fertilizers is effective. For sandy soils, adding magnesium is beneficial to increase yield. To ensure long-term fruiting and eliminate cavities, use fertilizers high in phosphorus. If the cucumber bed is in a shaded area, add more potassium to the fertilizer.

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Organic matter is also necessary to improve the soil composition and enrich the plants with nutrients. However, it should be used sparingly, and I try not to allow the soil to contain too much nitrogen. Otherwise, the plants will actively develop foliage at the expense of fruit development.

Foliar feeding is beneficial for plants. For example, spraying with an infusion of weeds. To prepare it, cut off the green parts of the weeds and chop them finely. Fill a bucket halfway with the plant material. Top up the rest with hot water. Leave the sealed container in the light until the fermentation process is complete. Then strain the liquid and dilute it with clean water at a ratio of 1:10.

Soil characteristics

When growing cucumbers, soil composition is important, regardless of whether the vegetable is grown in an open garden bed or a greenhouse. Soil provides the plants with the nutrients they need for healthy development. To ensure a healthy harvest, ensure the soil has a balanced nutrient content.

Fruit quality is reduced by pathogens and disease-causing agents found in the soil. Infections disrupt plant tissue development. Pathogen activity typically intensifies in hot weather, when all plant processes occur at a rapid rate.

Poor lighting

A constant stream of light is necessary for normal development of the tops, but the fruits gain weight better in light shade. Insufficient light in a greenhouse leads to improper development of cucumbers and the appearance of hollow bodies. A lack of sunlight impairs the flavor of greenhouse cucumbers and reduces their size and weight. To maintain optimal conditions, cucumbers are placed on a trellis.

Temperature difference

Significant temperature fluctuations are common in summer in many vegetable-growing regions. Typically, the problem arises when there is intense heat during the day and cooling at night. When growing cucumbers in greenhouses, growers can control the air temperature, maintaining it within the desired range. This is impossible in unprotected beds. In southern regions, sudden temperature changes are rare. However, in more northern areas, it is more convenient to grow cucumbers in greenhouses, avoiding open ground.

Diseases

Under unfavorable conditions, plants experience stress and their immunity is weakened. This increases the risk of infectious diseases. Viral infections result in defective fruits, and yield losses range from 20 to 50%.

Fruit deformation and death of cucumber bushes from virus infection can be prevented by observing the following conditions:

• growing plants taking into account crop rotation rules;
• using healthy seed material for sowing;
• growing varieties with high immunity to virus infection;
• soil disinfection using fungicides;
• correct application of fertilizers and irrigation.

To improve plant immunity, plants are treated with solutions of growth-promoting compounds. When used in the correct ratio, yields increase even under unfavorable conditions.

Untimely harvesting of fruits

According to the rules, cucumbers are harvested within the first few days after they reach ripeness. Left in the garden, cucumbers stop ripening, become overripe, and develop seed heads. These seed heads create a hollow space inside the fruit. The skin of overripe cucumbers hardens, and they consume moisture from their internal reserves. This usually happens to varieties that require pollination.

Ways to solve the problem

The appearance of hollow cucumbers in a garden doesn't always mean the entire crop is lost. Early detection can help solve the problem. To resolve it, adjust the growing conditions and watering schedule:

1. For irrigation, use only warm water, heated to a temperature of 22 to 24 degrees Celsius. This ensures that the roots absorb the required amount of moisture, and any excess evaporates.
2. In cloudy, rainy weather, irrigation is limited, since the root system is not able to absorb water in such conditions.
3. When watering, reduce the spray pressure. Direct the water directly at the roots, avoiding soil erosion. Spray the tops late in the evening, after sunset.

If there are a large number of hollow fruits, correct lighting errors. Bushes are thinned to reduce shading. If the beds are shaded during greenhouse cultivation, additional UV lighting is installed inside the shelter.

Prevention

For planting, use seeds from varieties adapted to the soil and climate conditions of the growing region. To prevent voids from forming inside the fruit, control the soil composition, avoiding excessive nitrogen levels.

To protect against diseases, the bushes are sprayed with a mullein solution. The fertilizer is prepared by mixing 1 kg of organic matter and 3 liters of water. The solution is left to infuse for 3 days. Then, the solution is diluted with the same volume of water.

To prevent cracks in plant tissue and voids in the fruit, cucumber plantings are treated with a whey solution. It is prepared from equal parts water and sour milk. To protect against viral infections, the bushes and soil are treated with a potassium permanganate solution.

When grown in a greenhouse, plants are regularly sprayed with a 2% formalin solution at a rate of 1 liter per square meter. The greenhouse is ventilated in the evenings. In cloudy or rainy weather, the doors are opened during the day. If the temperature drops below 20 degrees Celsius, outdoor plants are covered with spunbond. In greenhouses, the temperature is regulated using heaters.

To avoid the development of poor-quality fruit, proper agricultural practices are followed when growing cucumbers. The formation of hollow fruit can be caused by improper cultivation, unsuitable conditions, and certain diseases. To prevent hollow fruit, timely preventative measures are taken.