Onion downy mildew

What to do Grow resistant lettuces such as Saladin or Avoncrisp. Remove infected leaves if it continues, remove and destroy all infected plants. Use a five-year rotation for vegetables and susceptible ornamentals. See also Onion downy mildew. 

What to do Do not grow onions for five years where onion downy mildew has occurred. Do not save seed from infected onions. Break the cycle—give up growing onions altogether for a year or two. Remove infected plants as soon as seen. Remove weeds to encourage good air flow around plants. 

Escape Shorter crop growth period and/or early ripening to be able to avoid the critical infestation period, or to have enough yield before the infestation becomes too severe (potato/late blight onion/downy mildew carrot/carrot fly) One or more monofactorial and multifactorial, durable resistance traits against pest and disease affecting yield and/or quality (scab/apple, late blight/potato, lettuce/downy mildew, yellow and brown leaf rust/wheat) weed competition by an allelochemical ability... 

Uses as fungicide to control late blights of potatoes and tomatoes downy mildews of hops, vines, lettuce, onions, soybeans and other crops many diseases in flowers and ornamentals and often used in combination with other fungicides, etc. 

Chives are closely related to onions and prone to the same problems, especially rust, downy mildew, and smut. See the Onion entry beginning on page 155 for information. 

The following can affect bulb onions leaf blotch, downy mildew, onion white rot, neck rot, onion fly, cutworms, bean seed fly, thrips and bulb and stem nematode. 

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