Round spots of white or cream color are the first sign that cucumbers have been attacked by powdery mildew.
In order to avoid having to deal with the consequences of a dangerous disease, which, as we know, is not easy, you should take care of prevention in advance.
Firstly, it is worth giving preference to cucumber varieties that are resistant to the disease.
Secondly, with the onset of autumn, do not forget to clean up the greenhouse.
Fungi that are the causative agent of the disease can survive the winter safely, remaining on plant debris, soil or greenhouse structures. For this reason, it is worth removing all garbage from the greenhouse and burning it, and treating the structure itself with copper sulfate.
Thirdly, follow crop rotation rules and try to alternate cucumbers with unrelated crops.
Fourthly, do not use cold water to water cucumber beds.
In addition, when watering, make sure that the soil is not over-moistened and that water does not get on the leaves.
Finally, fifthly, if possible, make sure that the air temperature in the greenhouse remains above +20 degrees. Do not leave the greenhouse doors open at night, and when cold weather approaches, cover the plants with film.
