Here are some important points to consider while managing downy mildew of onion:<\/p>\n
Question:\u00a0\u00a0 \u201cI found some downy in my onions today.\u00a0 It has been sunny, clear, and low humidity all week long. \u00a0I thought downy liked humid, wet, cloudy weather.\u00a0 Why am I seeing it?\u201d<\/p>\n
Response:\u00a0 Yes, you are correct.\u00a0 Downy mildew development is favored by rain or dew on leaves, high humidity, and cool weather (below 70 degrees F).\u00a0 Warm, sunny weather with low humidity drastically slows down the disease.\u00a0 However, keep in mind that the downy mildew infection cycle on onions can take anywhere from 10 to 18 days, and it can take that long for the symptoms to show up.\u00a0This means that what you just found this week could have been infected over 2 weeks ago<\/u><\/b>\u00a0when the weather and conditions were favorable. Weather conditions this week likely slowed down further infections (but we are not out of the woods yet!)<\/p>\n
2.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Question: \u201cI just sprayed my onions with Orondis last week.\u00a0 This week I found some downy.\u00a0 I thought Orondis (or other fungicide) was supposed to \u201ckill\u201d downy and have a \u201ccurative\u201d effect. Why did it still show up?<\/p>\n
Response:\u00a0 Orondis is a great option for downy prevention and control.\u00a0 Here are a few things to keep in mind:\u00a0 There is not any fungicide that is going to give you 100% control when downy is present and conditions are favorable for disease.<\/u><\/b>\u00a0 In fact, under extended or prolonged favorable conditions, it can be quite hard to stop the disease from spreading.\u00a0 I don\u2019t want you to think you are wasting your money on a fungicide if you are still seeing some downy.\u00a0 It would likely be much worse if you did nothing.<\/p>\n
3.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Can I tank mix Orondis Ultra with \u201c__________\u201d fungicide?<\/p>\n
Response:\u00a0 Orondis Ultra is a relatively new fungicide to our onion market.\u00a0 Many of us are trying some new tank mixes with it for the first time on onions.\u00a0 It is impossible to know and predict what will happen to any spray product mixture because there are so many factors to consider (rate, pH of water, use of adjuvants, temperature, humidity, sunny, cloudy, etc\u2026..) The only way to know for sure about a new mixture is to do a \u201cjar\u201d test to see if it will stay in solution. \u00a0I will tell you this:\u00a0 at the Onion Research farm, we have sprayed Orondis Ultra with Bravo and surfactant for an application, and we have also sprayed it with Luna Tranquility plus surfactant.\u00a0 Dr. Dutta, our pathologist has also used it with Phosphorous Acid products (Kphite, Phostrol, etc.) \u00a0\u00a0We have not seen any issues with these mixtures at our farm.\u00a0 I called the folks at Syngenta, the makers of Orondis, to see if they could tell me any additional info.\u00a0 They don\u2019t have any additional tank mix info to add other than that they believe it tank mixes well with most other fungicides, and that we need to use a surfactant with it to help it get into the plant.<\/p>\n
4.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Can I spread downy on my farm with equipment or people?<\/p>\n
Response: Yes. \u00a0The worst time to spread it is probably early in the day when dew is present.\u00a0 If you find some, you should not go to any other fields without changing clothes and boots and washing your hands.\u00a0 This is also true for equipment.\u00a0 If you have a known spot of downy, spray that area last, and wash off your equipment before you go into another field.<\/p>\n
5.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0What fungicides are \u201csystemic\u201d (get into the plant) and which ones are \u201cprotectant\u201d (don\u2019t get into plant but provide a layer of protection)?<\/p>\n
Response:\u00a0 Orondis Ultra, Zampro, Omega 500, Phosphorous Acid products, and the \u201cRidomil\u201d part of Ridomil Gold Bravo are either systemic or locally systemic.\u00a0 Bravo and Manzate are protectants.\u00a0 One way to further enhance your disease protection is to use both a \u201csystemic\u201d and \u201cprotectant\u201d when you spray.\u00a0 For example, Orondis Ultra + Bravo, or Bravo + Phosphoric Acid, or Zampro + Manzate.\u00a0 However, do not mix Phosphorous Acid products with Manzate.\u00a0 Some fungicides are combinations of both systemic and protectant, like Ridomil Gold Bravo and Orondis Opti (Orondis + Bravo)<\/p>\n","protected":false},"excerpt":{"rendered":"
Here are some important points to consider while managing downy mildew of onion: Question:\u00a0\u00a0 \u201cI found some downy in my onions today.\u00a0 It has been sunny, clear, and low humidity all week long. \u00a0I thought downy liked humid, wet, cloudy weather.\u00a0 Why am I seeing it?\u201d Response:\u00a0 Yes, you are correct.\u00a0 Downy mildew development is […]<\/p>\n","protected":false},"author":186,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-546","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/site.caes.uga.edu\/vegpath\/wp-json\/wp\/v2\/posts\/546","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/site.caes.uga.edu\/vegpath\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/site.caes.uga.edu\/vegpath\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/site.caes.uga.edu\/vegpath\/wp-json\/wp\/v2\/users\/186"}],"replies":[{"embeddable":true,"href":"https:\/\/site.caes.uga.edu\/vegpath\/wp-json\/wp\/v2\/comments?post=546"}],"version-history":[{"count":1,"href":"https:\/\/site.caes.uga.edu\/vegpath\/wp-json\/wp\/v2\/posts\/546\/revisions"}],"predecessor-version":[{"id":547,"href":"https:\/\/site.caes.uga.edu\/vegpath\/wp-json\/wp\/v2\/posts\/546\/revisions\/547"}],"wp:attachment":[{"href":"https:\/\/site.caes.uga.edu\/vegpath\/wp-json\/wp\/v2\/media?parent=546"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/site.caes.uga.edu\/vegpath\/wp-json\/wp\/v2\/categories?post=546"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/site.caes.uga.edu\/vegpath\/wp-json\/wp\/v2\/tags?post=546"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}