High temperature and stuffy shed can prevent greenhouse diseases
Downy mildew, anthracnose, sclerotinia, powdery mildew and other diseases, the suitable temperature for germs to harm cucumber is 20 to 30 degrees Celsius. Therefore, as long as the maximum temperature in the greenhouse is controlled within a certain range above 30 degrees Celsius and maintained for a period of time, the occurrence of the above-mentioned diseases can be suppressed, and the appropriate high temperature does not affect the growth of cucumbers.
The method is, about 40 days after the cucumbers are transplanted in the spring greenhouse, the measures of closing the door and side air outlet of the greenhouse are used to conduct a high-temperature stuffy shed every 1 to 2 days. The time is around noon, and the maximum temperature in the shed is controlled at 40 to 47 degrees Celsius and last for about 2 hours, of which the temperature above 42 degrees Celsius needs to be maintained for about 1.5 hours, and the temperature above 45 degrees Celsius needs to be maintained for about 1 hour.
It must be noted that every time the high temperature and stuffy shed reaches 2 hours, it should be ventilated immediately to prevent the lack of carbon dioxide in the shed from affecting the photosynthesis of the leaves. During the high temperature and stuffy shed, the soil in the greenhouse should be kept moist. If the soil is dry, it should be watered in advance, and then the shed should be stuffed. During the high temperature control period, the extreme maximum temperature should not be higher than 48 degrees Celsius, and the control time should not exceed 2.5 hours, otherwise it will affect the normal growth of cucumbers.
