Downy Mildew on Cucumbers

I am very sad this morning to write that what was a flourishing row of cucumber plants just a week ago has been decimated by downy mildew. When I noticed damage on just a few leaves a couple days ago, I didn't want to do anything until I found out what the problem was, by the time I realized I had downy mildew, much of the beautiful giant leaves on my 5 week old vines had been affected. I trimmed off probably half of the foliage yesterday, sanitizing scissors between each leaf. I would post pictures, but at this point I am virtually certain of the issue.

I usually find myself hoping for rain and moderate temperatures but now I'm hoping for a hot drought down here in Central Florida to control the issue. I am also noticing that the tendrils on my vines are turning yellow and starting to harden...I am hopeful that the tiny little cukes that started forming last week can outrun the disease. 

With all that said, does anyone have any experience working with downy mildew? I am ordering Zonix Biofungicide because "organic" options seem very limited. Should I be worried about this spreading to the rest of my crops? Thank you for any help.

BrianDorry,
 I have more of a problem with Powdery Mildew here in SOCAL, so I am much more familiar with it, but the results, if left untreated, are the same. The mildew saps the plants energy and vitality, causing reduced production and eventual death of the plant. That said, there are fungicides that can be sprayed, but this gets to be a pain and expensive.
 Some things you can do in the future:
  - Learn the conditions that Downy Mildew requires to grow so that you know when to start watching for it.
  - Learn the gardening procedures that you need to follow to prevent or at least reduce the spreading of the disease, such as not getting water on the plants when watering, this to include splash.
  - Check this link for known outbreaks and other vital information:
       http://cdm.ipmpipe.org
  - Know what you are going to do, treatment wise, and have any treatments on hand during favorable conditions. The sooner you start treatment, the better.
  - In the future, try to grow cultivars that are resistant to the disease so that if it does become a problem, you at least get a partial crop. This is probably the most important as Downy Mildew spores blow in the wind, so if weather conditions are favorable, your plants are going to be exposed.

As I read, Downy Mildew affects the curcubits and cantaloupe.

Hope this helps some for future plantings. You probably know more about current treatment than I do.

Aw, that's such a bummer, Brian.  Cukes are about the only plant where, if it gets sick, I lose it.   

I, too, only get powdery mildew (never thought I'd say 'only' ).  And for that I spray with milk.  Works great.  

Let us know how you do with the Zonix Biofungicide.  Also, how did you know it was downy and not powdery?

CC

Thanks for the tips everyone. Everything was going so well that I probably just let my guard down, should have been more prepared for something like this and in the future I will be. We had about a week and a half of abnormally cool weather and late afternoon rain and that likely triggered it.

CapeGoddess, Downy and Powdery look very different from my research. If you search images of Downy Mildew, you'll see there is a very distinct pattern where the bad spots on the leaves start and stop within the borders of the leaf veins. At first I thought it was anthracnose, which wouldn't have been much better, but upon further research and by using the link posted in the comment above yours, I was able to confirm that the symptoms matched and that there was indeed a threat in my area (Tampa, FL). 

I'll do my best to save these plants, and find an heirloom species that is resistant to it (hopefully) and set some more seeds...it won't be ideal timing, but it will be better than nothing.

Brian, Bummer.

I get downy mildew on my cucumbers and squash every year.  Last year I was able to overcome the disease by inspecting frequently, when it appeared, I cut off the infected leaves and sprayed a couple of times with copper fungicide.  That seemed to work fairly well.   Here are a couple more articles:

http://www.carolinafarmstewards.org/wp-content/uploads/2012/12/4-ATTRA-Downy-Mildew-Control-in-Cucurbits.pdf


http://web.aces.uiuc.edu/vista/pdf_pubs/927.pdf

This year, I decided to wait until after the spring rains ended before planting.  Hope this works because I hate spraying anything on my veggies.

I too have gotten powdery mildew for the past few years. I have found great success at helping the plant survive by spraying the leafs all over with milk.

Sprayed the winter squash with milk tonight. Hope to keep it under control this year.

What is the milk water ratio, please? My patty pan squash plants rash owing some dusty powdery mildew on their leaves today!

About 1:1. I think some use as little as 1:10.

Thanks, Sanderson!

So I sprayed milk 1:2 yesterday. Sould I spray again today? Will it hurt anything if I do?

I don't think it will hurt.  What say others?

New reader: The title of the topic is Downy mildew. The milk treatment is for Powdery mildew.

I wouldn't do it again in my garden unless it has rained or the leaves had somehow gotten wet. I'd wait at least a week then spray the new leaves. But that could be just because I'm a lazy gardener and for me less is better.

CC

sanderson wrote:I don't think it will hurt.  What say others?

New reader:  The title of the topic is Downy mildew.  The milk treatment is for Powdery mildew.

OK, good time to bring this up, sanderson.  I am new here, and usually search the site for a term, in this case I searched "powdery mildew" and this was the most recent, relevant thread.  Should I use a similar but not on point thread, or start a new one?

Scorpio Rising wrote:

sanderson wrote:I don't think it will hurt.  What say others?

New reader:  The title of the topic is Downy mildew.  The milk treatment is for Powdery mildew.

OK, good time to bring this up, sanderson.  I am new here, and usually search the site for a term, in this case I searched "powdery mildew" and this was the most recent, relevant thread.  Should I use a similar but not on point thread, or start a new one?

Type in mildew in the search box, there are a lot of threads on powdery mildew but not real recent.  But that doesn't matter that they are not recent, by adding a comment you will make them recent.

This is fine for here. Next time you search and find a topic you are interested in, just bring up the most recent or on point. We are all guilty of slightly highjacking topics.

OK thanks.

I think I have downy mildew. Can anyone tell if I am correct?

Zucchini


Cucumber

If I am correct, what do I need to do? From what I can tell, I cut off all the infected leaves and spray with Copper

None of these actually look like DM to me, but seem  to possibly be 3 different issues. I recommend contacting your  extension service agricultrlural agent.

Ralitaco - growing in the South.  We get diseased veggies before many gardeners have even planted.  The Cucumber looks exactly like what I have.  I also thought Downy Mildew.  I am going to take mine to the county extension office (just as soon as my newly pored concrete driveway dries enough for me to drive on it).

RT, yeah, looks like downy mildew

https://www.google.com/search?q=downy+mildew+cucumber&client=safari&hl=en-us&prmd=sivn&source=lnms&tbm=isch&sa=X&ved=0ahUKEwip0NH7sOLMAhWq5IMKHVCLACQQ_AUICCgC&biw=1024&bih=671#imgrc=ouh8YBvztglycM%3A

Will have to do some research. I have only experienced powderey mildew.

maybe I don't know what downy mildew actually looks like....

https://www.cals.ncsu.edu/plantpath/extension/fact_sheets/Cucurbits_-_Downy_Mildew.htm

Good read!

I can never seem to match a sick leaf with a disease pic online...especially cukes...mildews, leaf spots, anthracnose, blight, viruses, etc.  One year my leaves slowly faded to brown and a county extension agent said it looked like mite/aphid damage (leaves being sucked dry)...neem oil on new leaves seemed to do the trick.

Last year there was so much rain, I think I had multiple diseases with nearly 0% harvest.