Epidemiology, prediction and control of onion downy mildew caused byPeronospora destructor

  title={Epidemiology, prediction and control of onion downy mildew caused byPeronospora destructor},
  author={Josef Palti},
  • J. Palti
  • Published 1 March 1989
  • Biology
  • Phytoparasitica
The effect of environmental factors on the development of each stage ofPeronospora destructor (Berk.) Caspary on onions is reviewed. For sporulation to take place, a period of light must precede the period of darkness and high humidity in which spores are formed. Spores are discharged when the relative humidity (RH) is increasing or decreasing, and over a wide range of temperatures. Their discharge is triggered by exposure to red-infrared radiation and by vibration of the leaf. Dissemination of… 


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