An Introduction to the Growth Habits and Key Cultivation Techniques of Cucumber

Cucumber is one of the vegetable types with the largest greenhouse cultivation area in the north, and it is also the earliest vegetable variety to be grown in greenhouses. After nearly thirty years of development, cucumber varieties have continuously improved. In earlier years, vegetable growers paid more attention to increasing yield, while in recent years people have placed increasingly higher demands on vegetable quality. The following is an introduction to the growth habits and key cultivation techniques of the common vegetable cucumber, and we hope it will help everyone.

I. Growth Habits of Cucumber

1. Temperature. Cucumber likes warmth and cannot tolerate cold. The suitable temperature for growth is 10 to 32 degrees Celsius. Generally, growth is best at 25 to 32 degrees Celsius during the day and 15 to 18 degrees Celsius at night. The most suitable soil temperature is 20 to 25 degrees Celsius, with a minimum of about 15 degrees Celsius. The most suitable day-night temperature difference is 10 to 15 degrees Celsius. At high temperatures of 35 degrees Celsius, cucumber photosynthesis is poor; at 45 degrees Celsius, high-temperature damage occurs; at low temperatures of -2 to 0 degrees Celsius, the plants freeze to death. If subjected to low-temperature hardening, they can withstand temperatures as low as 3 degrees Celsius.

2. Light. South China-type varieties are relatively sensitive to short-day conditions, while North China-type varieties are not strict about day length and have become day-neutral plants. Their light saturation point is 55,000 lux, and their light compensation point is 1,500 lux. Most varieties grow well under short-day conditions of 8 to 11 hours.

3. Water. Cucumber has high yield and a high water requirement. The suitable soil moisture is 60 to 90%. During the seedling stage, water should not be excessive, and soil moisture should be 60 to 70%. During the fruiting stage, sufficient water must be supplied, with soil moisture at 80 to 90%. The suitable relative air humidity for cucumber is 60 to 90%. If the relative air humidity is too high, disease is very likely to occur and cause reduced yield.

4. Soil. Cucumber likes moisture but cannot tolerate waterlogging, and likes fertilizer but cannot tolerate excessive fertilizer. It is best to choose fertile soil rich in organic matter. It generally prefers soil with a pH between 5.5 and 7.2, but a pH of 6.5 is best.

II. Key Cultivation Techniques for Cucumber

1. Early Fruit Removal

Cucumber is a crop that bears fruit relatively early. Its vegetative growth period is short, and it will flower and bear fruit after just a few leaves. In production, problems such as deformed fruit and weak growth vigor often appear. The purpose of early fruit removal is to reduce early deformed cucumbers, reduce premature consumption of nutrients, and prevent disease. Why does it prevent disease? Because most diseases easily infect senescent leaf tissues. Once the early cucumbers are removed, growth vigor is noticeably enhanced, so diseases are reduced. Therefore, it is recommended to remove the young cucumbers that form first, especially on plants with weak growth vigor.

2. Mid-stage Leaf Removal

I have seen quite a few posts about cucumber problems, and most involve diseases mainly caused by lower fungi such as downy mildew and bacterial angular leaf spot, and most have reached the late stage, an advanced stage that is beyond remedy. The two most important factors related to disease occurrence are leaf senescence and humidity. Mid-stage leaf removal means promptly removing old lower leaves and diseased leaves. Depending on the situation, remove middle leaves that bear no fruit. This effectively reduces the initial pathogens, increases ventilation and light penetration, and lowers the degree of leaf condensation. In this way, the triangular relationship of disease occurrence is cut off, and reducing the degree of disease occurrence is beyond doubt.

3. Pinching Off the Growing Tip as Appropriate

Why pinch off the growing tip? Because we will find that in the later stage, cucumber quality drops greatly. What should be done? If old branches are allowed to continue bearing cucumbers, the quality of the cucumbers will certainly not be good. If, when market prices are unfavorable, the growing tip is pinched off at the right time and axillary buds are allowed to bear cucumbers again from new branches, that is a good technique. Don't believe it? You can try it.

4. Spraying Boron and Calcium Supplements

There is no need to say much about this issue. Spraying boron and calcium on cucumber leaves plays an irreplaceable role in normal leaf growth, flower bud differentiation, and fruit growth.

5. Disease Control, with Prevention First

Not every disease needs to be treated; just focus on those that greatly affect growth, yield, and quality. This point is very important. In philosophy, this is called grasping the principal contradiction. In farming terms, it is called focusing on the key points. The prominent diseases of cucumber are downy mildew and angular leaf spot. On the basis of selecting disease-resistant varieties, emphasizing leaf removal, and strengthening ventilation and dehumidification, the most important thing of all is to prevent disease as early as possible, no later than the 6-leaf stage. This is required by disease prevention strategy and is even more a requirement for reducing pesticide residues.