Precautions for the prevention and treatment of cucumber black spot

Cucumber is a common vegetable in life. Eating cucumber can supplement a variety of vitamins in the body. In the process of cucumber planting, many diseases will occur. Among them, melasma is a common disease. This article will introduce the instructions for the prevention and treatment of cucumber black spot disease for your reference.

First, the symptoms of cucumber black spot

Generally, the middle and lower parts first develop, and then gradually develop upward. The initial leaf back is water-immersed round or irregular lesions, yellow-white in the middle, yellow-brown on the edges, rough surface at the later stage, slightly uplifted, and a faint green halo. Most of the lesions are between the veins and rarely occur in the veins. On the upper part, multiple lesions are connected in one piece, so that the mesophyll tissue is dead, like a fire-roasted, does not fall off. When the humidity is high, a dark brown mold layer can be seen. In severely ill fields, strains are often found, and in addition to heart leaves and unexpanded young leaves, all the leaves are affected. The onset of this disease is in the period of melon, and if the prevention is not timely, it will lead to production.

Second, cucumber black spot prevention and treatment methods

1. Agricultural control. Seeds were sterilized before sowing, soaking for 15 minutes at 50 ° C - 60 ° C water temperature, or soaking seeds with 50% carbendazim powder 500 times for 20 minutes, then rinsed with water and then germinated. Apply fertilized organic fertilizer, and increase the application of phosphorus and potassium fertilizer to enhance the disease resistance of the plant. Covered with high mulch film. Control the amount of water to prevent flooding. 2-3 years of rotation with non-melon crops.

2. Chemical control. The key to the prevention and treatment of melasma is that it must be carried out before or at the onset of the disease. Protected areas can be controlled by dust and aerosol at the beginning of the disease. Spray 5% chlorothalonil dust in the evening, use 1 kg per acre; or illuminate 45% chlorothalonil in the evening, 250-300 grams per acre; or each acre Use 15% anti-virus smog agent 300-400 grams, spray once every 7-9 days, depending on the condition and alternately use with dust. It can also be used in the early stage of the disease with 75% chlorothalonil or 40% captan powder WP 500-600 times or 50% chlorhexidine powder 1500 times solution, 7-9 days spray, alternating use, continuous 3- 4 times. When the condition spreads rapidly, it can be sprayed once with 20% Shibaoling Suspension 10,000-1.5 million times, and then continuously treated with other chemicals.