What is the effect of temperature on cucumber?

Cucumber prefers warm to cold. The suitable temperature for growth is 10 ~ 32℃. Generally, it grows best at 25 ~ 32℃ in the daytime and 15 ~ 18℃ at night. The optimum ground temperature is 20 ~ 25℃, and the lowest is about 65438 05℃. The optimum temperature difference between day and night is 10 ~ 15℃. Cucumber has poor photosynthesis at high temperature of 35℃, high temperature obstacle appears at 45℃, and it freezes to death at low temperature of -2 ~ 0℃. If the seedlings are trained at low temperature, they can bear the low temperature of 3℃. Post-planting management

(1) Pre-management: The management in this period is called pre-management, and the center of pre-management is root promotion and seedling control. Although the temperature and light in this period have obviously decreased, they have not reached the lowest point. It is necessary to make full use of the favorable climatic conditions in this period, strengthen management, promote root development and enhance the adaptability of plants to low temperature, weak light and special weather. The technical level of early management has an important influence on plant growth, disease resistance, cold tolerance and yield in the middle and late stage. Watering the first three waters well: first, water should be poured well to prevent the soil from being layered with the surrounding soil, which will affect the slow seedling. During the period of 10- 15 days after planting, slow seedling water should be thoroughly poured from the culvert in the middle of the border to the planting hole. After the root melon is harvested, water it for the third time on a sunny morning, which is also called melon urging water. Root promotion and seedling control: within one week after planting, the temperature is 25-32℃ during the day and 15- 17℃ at night. After delaying the emergence of seedlings, the air release should be increased, and the maximum air release should not exceed 30℃ at noon on sunny days, 15- 12℃ at night, and it should be maintained at 10℃ before the curtain is lifted in the morning to increase the temperature difference between day and night and control the growth of aboveground parts. The temperature management is too high, the plants grow too vigorously, and the ability to resist low temperature and cold current decreases in the coldest 1 and February. At the same time, the leaves will be too large, the ground will be seriously shaded, and it will also affect the increase of ground temperature and the development of roots. Plant vine hanging and adjustment: when the plant grows to 6-7 leaves and begins to swing vines, pull the wire to hang vines in time. With the growth of the stems and vines, the stems and vines are wound on the lanyard, and then every 2-3 days.

(2) Mid-term management: the management from harvesting root melons to early March is called mid-term management. This period is the lowest temperature and the weakest light in winter cucumber production, which is a difficult period of management and the peak of output value formation. Temperature management: During this period, temperature management is the core. During the day, we should extend the lighting time as much as possible. Under the premise of not affecting the indoor temperature, open the straw curtain as soon as possible and implement four-level temperature change management. At 8: 00 am-13: 00 am, the temperature is controlled between 25-32℃, and the outdoor air is turned on when it exceeds 32℃. In the afternoon 13: 00- 15: 30, the photosynthetic capacity decreased obviously, and the temperature was maintained at 20-30℃. After the curtain is covered, the indoor temperature drops gently, and the temperature is maintained at 20- 15℃ in the first half of the night and at 12- 10℃ in the second half of the night, which is beneficial. The ground temperature should be kept above 65438 05℃. In the middle and late February, with the increase of temperature, sunshine hours and light intensity, the nutrients produced by plants increased, and the temperature at night also increased, from 22- 16℃ in the first half of the night to 15- 12℃ in the second half of the night, which was beneficial to the transportation of nutrients and the growth of melons. Humidity management: due to the low temperature in winter and small indoor ventilation, it is easy to form a high humidity environment and various diseases occur. In view of this feature, low temperature and low humidity management measures should be implemented. The air humidity is controlled at 60-80% during the day and 85-90% at night. Try not to drip the leaves in the morning. Try to reduce the number of watering, do not water without drought, let the air out after watering, and try to choose aerosol and dust when using drugs. Topdressing: With the increase of melon harvest, timely supplement nutrients. According to the harvest and plant performance, determine the variety and quantity of topdressing. Generally, topdressing starts from the water in the fourth water. If the leaves and melon strips are dark, nitrogen fertilizer should be the main topdressing, supplemented by phosphorus and potassium fertilizer, and attention should be paid to the supplement of trace elements such as calcium and magnesium. When applying fertilizer, the fertilizer should be dissolved first, and then topdressing with water. If the plants are light in color and have large leaves, phosphorus and potassium fertilizers are mainly applied. The amount of topdressing should follow the principle of "eat less and eat more meals" to avoid excessive topdressing at one time. After March, dilute manure and biogas slurry residue can be combined with water for topdressing, but attention should be paid to full decomposition and fermentation.

(3) post-management

Falling vines and picking leaves: With the growth of plants and the continuous harvest of melon strips, falling vines should be used when the growing point is close to the roof. The method is to untie the plastic rope tied to the wire above the falling vine, so that the growing point of cucumber can be lowered to a suitable height and then tied. Removing the old leaves and diseased leaves in time before the vine falls can reduce nutrient consumption, improve ventilation and light transmission conditions and avoid the spread of diseases.

Strengthen water and fertilizer management and extend the harvest period: after April, in order to prevent the plants from aging and fertilizing, the harvest period should be extended as much as possible. At this time, we should pay attention to strengthening fertilizer and water management, generally watering once every 5-7 days and topdressing once every 7- 10 days to ensure the quality of irrigation and fertilization. If there are flowers topping and shrinking, you can take boring tips and picking the heart to promote the growth of melons. In order to improve the commodity rate of melon strips, we should interplant curved melons, diseased melons and redundant small melons in time. Harvest must be timely, and the commodity rate and total output of melon strips should not be affected because of delayed harvest.

(4) management of special weather

In the case of cold current, cloudy to snow or even cloudy days, special management measures should be implemented to reduce or avoid the losses caused by disastrous weather to production. When the strong cold current comes, strict cold protection and heat preservation should be carried out, paper covers, grass curtains and other coverings should be added, and temporary indoor heating measures should be taken. When it snows, it should be cleaned in time to prevent the skeleton in the shed from collapsing due to excessive snow load. Harvest melon sticks as early as possible on cloudy days to reduce the consumption of nutrients by melon sticks, and try to open the straw curtain that scatters light for a certain period of time without obviously affecting the indoor cooling. After the weather suddenly clears up, foliar topdressing should be carried out to quickly replenish nutrients and increase the humidity in the shed. If the leaves are severely wilted, temporary greening can be properly carried out.