Deep winter cucumber safety management against three diseases

Among cucumber cultivation in winter greenhouses, cucumber downy mildew, bacterial angular spot, and cucumber spot disease are the most common headaches for vegetable farmers. Especially in recent years, diseases have developed rapidly and are difficult to control. For farmers, the specific symptoms of these three diseases are no stranger to the situation. The symptoms of cucumber downy mildew and bacterial angular spot disease are basically the same. In the early stages of the disease, water-soaked lesions appear on the back of leaves and the lesions gradually expand. The veins are limited to a polygonal brown spot. When the humidity is high, the moldy layer on the downy mildew grows out of the moldy layer of grayish black, while the bacterial angular spot disease is accompanied by the outflow of white bacteria.

There are many kinds of drugs for controlling cucumber downy mildew, for example, Prec, Amisida, dimethomorph and other agents can be used for the prevention and treatment of downy mildew, copper can be used for bacterial angular spot disease, antibiotics The bactericides such as bactericides and euzophenazole are used for the treatment. For the above two diseases, the measures for preventing diseases are reasonable, especially for cucumber downy mildew. Because of the large concentration of pesticides used by vegetable farmers, the repeated use of drugs causes the resistance of pathogens. The ability to constantly improve. Experts suggest that protective bactericides should be the mainstay in disease prevention. After the onset of illness, they must be changed to reduce the resistance of pathogenic bacteria.

Cucumber target spot disease is one of the most serious diseases in cucumber in recent years. The early stage of the lesion is a transparent small spot. Observation in the sun will find that the center of the lesion has a small yellow dot of the size of the tip, and the development of the latter spot is affected by the veins. The limitations are also irregular polygons. For diseased plants, 33.5% quinolinone 750-fold and 80% thiram 500-fold can be used for foliar application.

In addition to the prevention and control of the diseases of cucumber, the management of the greenhouse can not be ignored. First of all, we must do a good job in the regulation of the indoor environment of the shed. Generally, the daytime temperature should be controlled at 25~30°C, and the minimum temperature at night should be kept at 12~15°C. At the same time, it is necessary to enhance ventilation and dehumidification. Even when the temperature is low, the outlet should be opened as much as possible when the temperature inside the booth permits. At the same time, note that watering should be reduced during this time, smokers should use chlorothalonil and other smoke agents to reduce the humidity in the greenhouse. Even cloudy days should try to pull open the straw curtain so that the cucumbers receive scattered light.