What are the symptoms of spinach downy mildew? How to prevent spinach downy mildew

1. Symptoms of spinach downy mildew

   
   

    Downy mildew usually starts from the lower leaves. In the early stage of the disease, light green water-stain-like spots are produced, and the edges of the lesions are not obvious. Later, they develop into yellow irregular lesions. When the humidity is high, the back of the leaf produces a gray-white mildew layer, which gradually becomes Dark gray. The diseased leaves gradually turn yellow and dry when the shed is dry, and moldy and rot occurs when the air humidity is high. The occurrence of spinach downy mildew Downy mildew is a fungal disease caused by an oomycete. Low temperature, humid air or high humidity in the field, planting too densely, and poor ventilation and light transmission between plants can easily induce downy mildew. In general, stubble plots and sheds with excessive watering rate will cause severe disease.

    2. Control measures of spinach downy mildew

    1. Agricultural control.

    One is that 2-3 years of crop rotation should be implemented in seriously ill fields. Apply adequately decomposed organic fertilizer to improve plant resistance to disease.

    The second is reasonable close planting and scientific watering to prevent flooding from flooding to prevent diseases from spreading with water. Strengthen the ventilation and reduce the humidity.

    Third, if a diseased plant infested by downy mildew is found, it should be removed in time and taken out of the field to burn or bury it deeply. At the same time, sprinkle quicklime to treat the planting hole to prevent the spread of the disease source. When harvesting, thoroughly clean up the stubble and fallen leaves, and bring them to the field for deep burial or burn.