Greenhouse Cucumber Cultivation and Pest Control Technology

Abstract: Cultivation of cucumbers in greenhouses can effectively reduce the impact of climate problems on cucumber cultivation, and improve the quality and yield of cucumbers. However, because the temperature in the greenhouse is suitable and the space is relatively closed, it is easy to breed bacteria, resulting in the proliferation of diseases and insect pests of cucumbers in the greenhouse. Therefore, while increasing the research on the cultivation technology of cucumbers in greenhouses, improving the control technology of diseases and insect pests can effectively guarantee the yield and quality of cucumbers in the greenhouses.

1. The Main Cultivation Techniques of Greenhouse Cucumbers

1.1 Seed selection

The selection of varieties plays a decisive role in the yield and quality of greenhouse cucumbers. There are many varieties of cucumbers, such as ordinary cucumbers, fruit cucumbers and rootstock cucumbers. When choosing cucumber varieties, in addition to choosing excellent varieties, you should also pay attention to the following two issues. First, when selecting seeds, the principle of adapting to local conditions should be adhered to, fully considering whether the cucumber varieties are compatible with the local planting environment, and selecting varieties suitable for the local area to improve the germination rate. Second, pay attention to the pest and disease resistance of the variety to ensure that the cucumbers are not affected by pests and diseases.

1.2 Planting and raising seedlings

In order to improve the germination speed and germination rate of the seeds, the seeds can be blanched and sown according to the appropriate planting spacing. When the cucumber grows to three or four leaves, it should be planted. At this time, it should be placed on the wood chips soaked in nutrient-rich soil and keep it warm. In addition, the following three points should be paid attention to when raising seedlings. First, when choosing a seedling location, factors such as sunlight and moisture need to be considered, and the impact of the temperature and humidity of the external environment on cucumber seedlings cannot be ignored. Second, the size of the seedbed needs to be reasonably designed to meet the cucumber planting specifications. Third, the seedbed can be appropriately increased with base fertilizer to increase soil fertility and nutrients, and provide conditions for the growth of cucumber seedlings. At the same time, it needs to be watered to maintain soil moisture and provide a good growth environment for cucumbers.

1.3 Temperature and water and fertilizer control

It needs to control a certain range of temperature difference between day and night during the cucumber growth period. It is suitable to control the temperature of the greenhouse at 25-30 °C during the day and 13-18 °C at night. After the cucumber seedlings are set, a certain amount of nitrogen fertilizer needs to be added, and phosphorus and potassium fertilizers need to be added in the late stage of vine and flowering and fruiting. At the same time, during the growing period of cucumbers, watering work should be done well. In the early stage of cucumber sowing and transplanting, water requirements are relatively high, and water management should be done to ensure the survival rate of cucumbers and the quality of seedling emergence. In the harvesting stage of cucumbers, it is necessary to strictly control the amount of watering, insist on weeding and shallow tillage, and pay attention to the drainage and waterlogging prevention of cucumbers.

1.4 Field Management

Cucumber growth requires high terrain conditions. Therefore, when planting cucumbers, it is necessary to choose flat land to provide a good growing environment for cucumbers, and apply organic fertilizer or potassium sulfate fertilizer to them during the growing period of cucumbers. At the same time, pay attention to the following three points: First, build a frame. When planting cucumbers, after the cucumber seedlings grow to 10-15cm, a frame needs to be erected, and the distance from the roots of the cucumbers should be 6-8cm. Second, weeding. When the cucumber plants grow to a certain extent, weeding work should be carried out to avoid the situation of excessive growing of grass and absorbing cucumber nutrients. Third, shaping. If there are many female flowers on the main branch of cucumber, it needs to be removed in time to prevent excessive consumption of nutrients. When the main branch grows to 25-30 leaves, pinching is needed, and nitrogen, phosphorus, potassium and other fertilizers should be added in time after pinching to ensure the normal demand for nutrients in the growth of cucumber.

2. Greenhouse cucumber pest control technology

2.1 Downy mildew

2.1.1 Causes and symptoms

Downy mildew is a common disease of cucumbers grown in greenhouses. It mostly occurs in the early growth stage of cucumbers. The bacteria will slowly spread from the leaves and eventually turn into black mold. Downy mildew mainly damages the leaves and develops slowly from the lower leaves to the upper leaves. Chlorotic spots appear in the early stages of cucumber seedlings, which gradually turn into yellow, irregular-shaped lesions. When the humidity in the shed is high, the back of the leaves of the cucumber seedlings will show gray-black mold, and the leaves will quickly turn yellow and wither. When the cucumber is infected at the adult stage, the leaves will appear water-like chlorotic spots, which will slowly expand into yellow spots, and finally turn into brown withered spots. The disease overwinter and oversummer on the remaining leaves, mainly re-spread through the currents of air. When the temperature in the shed is 16-24 ℃, the humidity in the air reaches more than 80%, and there is dew on the leaves for more than 6 hours, it is the most suitable condition for the disease to occur. At the same time, excessive temperature difference between day and night, rainy and foggy or intensive planting, and excessive watering will induce disease epidemics.

2.1.2 Control methods

1) Choose disease-resistant varieties when selecting seeds.

2) When planting, choose a plot with higher terrain and better drainage for planting, and apply base fertilizer, increase phosphorus and potassium fertilizer, and control the amount of watering according to the actual disease situation.

3) Use bactericidal agents for spraying, spray with 75% chlorothalonil WP 500 times liquid in the early stage of the disease, and spray with 58% manganese zinc WP 500 times liquid or 69% manganese zinc alkenoyl WP 800 times liquid when the disease is severe.

2.2 Powdery mildew

2.2.1 Causes and symptoms

Powdery mildew, also known as white hair, is a fungal disease and a major disease of cucumbers. It is mainly harmful to the leaves of cucumbers, and in severe cases, it will also cause damage to the stems of cucumber plants, resulting in the death of pruning plants. In the early stage of plant disease, small white spots appear on the leaves, and then gradually expand to become contiguous white spots, and even spread all over the leaves. In the later stage of the disease, the spots will gradually turn gray-white, the leaves begin to wither, turn yellow, and sometimes black-brown spots grow on the leaves. Diseases overwinter on leaves that remain in the soil and are spread by wind and rain. The temperature of 10-30 ℃ is the best period of its onset. When it is in high temperature, dry and humid, it is also a favorable period for the onset of the disease.

2.2.2 Control methods

1) Select disease-resistant varieties.

2) Strengthen field management, strictly control temperature and humidity, strengthen ventilation, and deal with diseased plants in time.

3) Cover the plants with plastic film, strictly control the amount of watering, and apply enough fertilizer.

4) Spray the Baume Sulfur mixture, or apply the medicine directly to the affected area, use it once every 10 days, and use it 3-4 times.

2.3 Aphid

2.3.1 Causes and symptoms

Aphids are a common pest of cucumbers during the growth period, which damages the tender leaves, growing points and young melons of the plant. Aphids mostly live in groups, gather in groups on the surface of young leaves and young melons, and feed on the sap, causing the leaves to slowly turn yellow and eventually die. Aphids cause the young leaves of the plant to begin to shrink, slowly turn yellow, and eventually die. For young melons, aphids will cause them to start yellowing and then stop growing. Aphids secrete a lot of honeydew on the young leaves and young melons of plants, which can also cause infectious diseases.

2.3.2 Control methods

1) Use sweet and sour liquid to trap and kill aphids. Sweet and sour liquid formula: the ratio of wine, water, sugar and vinegar is 1:2:3:4. Put the prepared sweet and sour liquid in a container with an open top, and put it on the plant site where aphids occur in large numbers in the evening.

2) Apply 750-1125g of cypress pine per hectare for control.

3. Summary

Cucumber is a common vegetable on the human table, and its nutritional value and edible value are high. In order to improve the yield and quality of cucumber, it is necessary to conduct more in depth research on cucumber cultivation and pest control technology.