How to prevent and control long bubbles in cucumber leaves with long water-immersed spots on leaf surface

There are about 5 mm light green bubbles on the front of cucumber leaves, and then the number increases, and the back rarely occurs. This is the bubble disease of cucumber, and some people call it "scabies toad skin". It mainly occurs in the greenhouse and greenhouse in overwintering and early spring, which is a physiological disease. When it occurs, the leaf surface is uneven, the depression is in the shape of a white blanket, and there is no attachment to it. The protruding part of the leaf did not produce pathogen, and the top of the bubble faded green at the beginning, and gradually became yellowish, gray or yellowish brown. Sometimes water immersion spots appear on the top of the bubble (physiologically filled with water).

Cucumber bubble disease

First, the cause of occurrence:

The formation mechanism of ⑴ is generally regarded as the result of photosynthate deposition in cucumber leaves, which is related to low temperature and less light. The photosynthesis products in cucumber leaves can only be transported 15-20% during the day, and the remaining 80-85% need to be distributed to the growth point, fruit, root and other parts in the first half of the night. The running speed of the product is closely related to the temperature: all the operation and distribution is completed, which takes 2 hours at 20 ℃, 4 hours at 18 ℃, 6 hours at 16 ℃, and slow operation or even shutdown under 16 ℃. For example, the thermal insulation performance of the greenhouse is poor, the spring greenhouse closes the wind late in the evening, and the temperature is low in the middle of the night, which can not meet the needs of product operation, so some or all of the products remain in the leaves, which is called deposition. If it is deposited day by day, the mesophyll between the veins will be raised.

⑵ epidemic rule: cucumber has low temperature in the early growth stage, long cloudy and rainy days and weak light. After the beginning of spring, the weather suddenly clears up, the temperature rises quickly, the sunshine is sufficient, and the watering quantity increases, which is easy to induce bubble disease. In addition, it is also related to variety resistance and environment, and cucumber varieties that are not adapted to low temperature and light are prone to this disease.

2. Prevention methods:

⑴ selected varieties resistant to low temperature, low light and low light. ⑵ strengthens the measures of increasing temperature and heat preservation. In the afternoon, when the air temperature in the shed drops to about 20 ℃, it is necessary to cover grass grass or collect air to keep warm, and the ground temperature is kept at 15-18 ℃ to prevent low temperature freezing. ⑶ choose no drip film, often clean plastic film and glass on the shed, if necessary, artificial light and carbon dioxide can be applied. Rational irrigation of ⑷. Low temperature in cloudy days, irrigation should not be reduced; heating up in sunny days, avoid pouring water. Irrigation should avoid ups and downs. Generally speaking, the irrigation time should be on a sunny morning. ⑸ strengthens cultivation management to improve cucumber stress resistance. When planting ⑹ cucumber, we should increase the base fertilizer, pay attention to the cooperation of various elements, and keep warm and increase the temperature in time according to the change of air temperature. Timely prevention and control of diseases and insect pests.