Do not rely on excessive cooling

Recently, many vegetable farmers have reported that the cucumber leaves in the shed have turned yellow, and some have even died. The reporter saw in the shed of a vegetable farmer in Shangjia Village, Sunjiaji Street, Shouguang City. Yellow leaves were commonly found in the upper middle leaves of cucumbers, especially the cucumbers at the shed entrance and the front face were more serious. After ruling out the possibility of invasive diseases, the reporter initially diagnosed as hypothermia. However, the current weather is fine and the temperature inside the shed is not low. Why is there a low temperature barrier? The reporter was even puzzled. “How do you control the temperature?” “From the cucumber planting to the present 25 days, during which we basically did not let go haystacks, usually in the morning when the temperature is usually in the cabin 9-9 °C, but the most recent time the weather Cold, sometimes shed within 4 - 5 ° C. "Farmers told reporters. When a reporter asked a vegetable farmer why he did not give grass to the greenhouse, the answer was basically the same: “Cucumber prices are now low, only about a dollar a catty, we do not dare to make the cucumber grow quickly and control the temperature very low at night.” In fact, the reporter's inference should be correct, and cucumber yellow leaves are indeed low temperature barriers. At the same time, the reporter learned that the overwintering cucumbers in Sunjiaji Street, Shouguang City, are mostly planted in early November. If the price of cucumbers after planting is higher, the vegetable growers will be properly managed to allow them to sit normally. If the price of cucumbers is low, some vegetable farmers will By controlling the temperature let it grow slower. It is indeed possible to control the growth of cucumber through temperature regulation, but it is necessary to grasp the degree of goodness. Because of the low price of cucumber, the nighttime temperature will be controlled very low, even lower than 5 °C, which is tantamount to drinking thirsty. Compared with other vegetables, cucumber is less tolerant of cold, 0-10 °C will be victimized, and less than 3-5 °C physiological function obstacles, causing injury. This is because: the protozoa of root cells proliferate slowly or stop, and the osmotic pressure of the cells decreases, resulting in unbalanced water supply and demand. As a result, the leaves die and the plants become rigid, which seriously damages the normal production of cucumbers. To this end, the reporter reminded the vegetable farmers that the temperature control should also be controlled within the scope of suitable cucumber production, and never excessive cooling. To control growth and cultivate strong trees, it is recommended that the vegetable growers control at 25-28°C during the day and 10-13°C at night. For cucumbers with low temperature barriers, the reporter recommends doing the following: First, pay attention to insulation at night. The growth temperature of cucumber at night is about 10-13 °C. If the temperature is higher than the temperature in the shed after entering the shed in the morning, it is necessary to put straw to keep warm. If the temperature is too high at night after weaving grasshoppers, the booths without shutters can be adjusted by putting flowers. The shutters can be installed in the booths of the roller shutters to lower the grass weeds by one third or one half to ensure proper temperature in the booths. .