We have confirmed Downy Mildew of Vidalia Onion today in the growing region today.\u00a0 I am urging growers to please take precautions and protect their crop from this disease! <\/u><\/b>Here are your control options, based on the most recent (2018) UGA research data.\u00a0\u00a0I want to provide some options and how I rank them in terms of potential.\u00a0 I use these as a TIER system of better products to somewhat beneficial.\u00a0 Remember, a good downy spray program includes rotating chemistries\u00a0 and not relying solely on one product.\u00a0 A good spray program can include products from all of these \u201ctiers\u201d.<\/p>\n
\u00a0<\/i><\/b>TIER 1: (Most reliable,based on UGA data)<\/i><\/b><\/p>\n
Orondis Ultra<\/b>:\u00a0 Active ingredients are Oxathiapiprolin + Mandipropamid (Revus). In last year\u2019s trial it was a top performer.\u00a0 This product would be a good fit if you have an active outbreak, or for preventative use.\u00a0 It has curative activity.<\/p>\n
Bravo:\u00a0<\/b>Chlorothalonil alone has done well in UGA trials at preventing\/and protecting from downy.\u00a0 However, due to the active find of downy in the area, growers should not rely on it alone.\u00a0 It can be tank mixed with the other fungicides to increase protection.<\/p>\n
TIER 2: (Moderate\/Good)<\/i><\/b><\/p>\n
Orondis Opti<\/b>:\u00a0 Active Ingredients\u00a0Oxathiapiprolin + chlorothalonil (Bravo).\u00a0 Showed good results, did not do as well as Orondis Ultra or Bravo alone.\u00a0 Contains curative and protectant active ingredients<\/p>\n
Zampro<\/b>:\u00a0\u00a0 Active ingredients Ametoctradin + Dimethomorph.\u00a0 Showed good efficacy last year.<\/p>\n
Omega 500<\/b>: Active ingredient\u00a0Fluazinam.\u00a0 Showed good efficacy last year, also good for other diseases as well.<\/p>\n
**Reason<\/b>:\u00a0 In the past, Reason was a top tier product.\u00a0 Last year\u2019s data does not support this recommendation.\u00a0 We are changing our ranking of the product based on the most recent UGA data.<\/p>\n
TIER 3 (Some benefit):<\/b><\/p>\n
Phosphoric Acid<\/b>:\u00a0\u00a0Phosphoric acids such as Phostrol, ProPhyt, KPhite, and others have shown to be slightly effective at preventing downy in some studies. They are a cheaper option, and have some benefit to the overall fungicide program.<\/p>\n
Maneb<\/b>:\u00a0 \u00a0Dithane, Pencozeb, etc\u2026 the maneb products are listed as somewhat effective.\u00a0 I wouldn\u2019t count on much help if we get to the point of seeing downy, but they may be offering some prevention.<\/p>\n
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Take a look at these recent blog posts to find out more on downy mildew of onion:<\/p>\n