Downy Mildew Symptoms and Control

Posted Saturday, January 15, 2022 ( 9 months ago)

Last updated: January 18th, 2022

Let us examine the diseases and disease control of cabbage, cauliflower, Chinese cabbage, nocol, radish, and broccoli among the crops belonging to the genus Cucurbitaceae.

The causative agents are Pernospore and Pseudomonas aeruginosa. This is also a very harmful disease that affects crops in nurseries. Damages crops in nurseries as well as in paddy fields. High humidity and normal temperature increase the risk of infection.

Downy mildew Symptoms

The plant is at risk of infection at any time. The underside of the leaf blade becomes infected and the upper surface turns yellow. When the environmental conditions are favorable for the disease, the whole plant is destroyed.

Downy mildew Disease control

Keep the field clean, treat the seeds with hot water (15-25 minutes at 50 degrees Celsius, disinfect the nursery beds, maintain a clean nursery, control weeds, control crop rotation and overgrowth. Fungicides such as Captan, Mancozeb, Maneb, Propineb, and Chlorothalonil should be applied in recommended doses.

  • Downy mildew (Plasmopara viticola) affects many plants and appears as yellow to white spots on the upper surfaces of old leaves. On the underside, these areas range from white to gray, covered with cotton-like fungi. These "lower" masses are often visible after rain or heavy dew and disappear as soon as the sun's weather resumes. As the disease progresses, the leaves eventually become brittle and brown, even though the plant has enough water.
  • Powdery mildew usually occurs in early spring or late fall in cold, humid weather. Spore production is favored at temperatures above 65˚F. And relative humidity reaching 100%. The disease persists during the winter in plant debris and soil. Fungal spores can be carried by insects, wind, rain or garden tools.