Powdery Mildew or Downy Mildew or both?

SQWIBB · August 28, 2019

I'm a bit concerned with the cantaloupe, I'm worried the plant will be dead before the fruit matures! I treated with a Mix of water and milk hoping that it is powdery mildew and not Downy Mildew.

brownrexx · August 28, 2019

Looks like powdery mildew to me. I usually start seeing that on squash at this time of year.

I spray a mixture of baking soda and water when I have this problem. It does not kill the mildew, it just changes the pH to an unacceptable level and keeps it from growing. It needs to be re-applied frequently. I think that milk is supposed to act the same way but I do not want to smell sour milk.

SQWIBB · August 28, 2019

I have heard the baking soda and water mentioned before but with the addition of Dr. Bronners soap for adhesion.. any thoughts or recipes to share?

Sherry_AK · August 28, 2019

Looks like powdery mildew to me as well. I used the milk spray when I had an outbreak in 2016 (on all 100+ tomato plants). I sprayed gallons of milk. All I did that summer was spray milk solution. I had moved the plants out of the greenhouse for better control (all are grown in containers), but I never once smelled sour milk. I think it air dries so quickly that no odor can develop.

SQWIBB · August 28, 2019

Quote:

Originally Posted by Sherry_AK

Looks like powdery mildew to me as well. I used the milk spray when I had an outbreak in 2016 (on all 100+ tomato plants). I sprayed gallons of milk. All I did that summer was spray milk solution. I had moved the plants out of the greenhouse for better control (all are grown in containers), but I never once smelled sour milk. I think it air dries so quickly that no odor can develop.

Did it help?

Sherry_AK · August 29, 2019

It did. It did not "cure" the problem, but made it manageable. I was able to give the plants a little more space by moving them outdoors and sprayed at least every two days or more often if the rain washed it off. Of course, mine was on tomatoes and not squash. From what I read at the time, the powdery mildews are host-specific so the one on squash may respond differently. I'd say it's worth a try.

brownrexx · August 29, 2019

Sorry, but I don't remember the baking soda recipe. I just Googled it at the time. I never tried the milk. I just assumed that it might smell sour in my sprayer.

For my baking soda solution, I just made up a quart hand sprayer full and used what I needed and stored the rest in the garage until I re-applied it. I don't think that this would be a good idea with milk.

I did not add any soap or oil, just baking soda and water. It didn't kill the old mildew but it seemed to keep it from spreading to the new leaves. I had the problem on zucchini.

Sherry_AK · August 29, 2019

A good article...

https://www.growingagreenerworld.com...owdery-mildew/

Cole_Robbie · August 29, 2019

Peroxide will kill the mildew. I dilute the drug store 3% 2:1, end mixture 1.5%. It works really well but is not cost effective on a larger scale. There are a lot of other homemade fungicides that work, too, I'm sure.

August 28, 2019	#1
SQWIBB Tomatovillian™ Join Date: Jan 2018 Location: Philly 7A Posts: 739	Powdery Mildew or Downy Mildew or both? I'm a bit concerned with the cantaloupe, I'm worried the plant will be dead before the fruit matures! I treated with a Mix of water and milk hoping that it is powdery mildew and not Downy Mildew.

August 28, 2019	#2
brownrexx Tomatovillian™ Join Date: Feb 2016 Location: Southeastern PA Posts: 1,420	Looks like powdery mildew to me. I usually start seeing that on squash at this time of year. I spray a mixture of baking soda and water when I have this problem. It does not kill the mildew, it just changes the pH to an unacceptable level and keeps it from growing. It needs to be re-applied frequently. I think that milk is supposed to act the same way but I do not want to smell sour milk.

August 28, 2019	#4
Sherry_AK Tomatovillian™ Join Date: Jan 2006 Location: Alaska Zone 3/4 Posts: 1,857	Looks like powdery mildew to me as well. I used the milk spray when I had an outbreak in 2016 (on all 100+ tomato plants). I sprayed gallons of milk. All I did that summer was spray milk solution. I had moved the plants out of the greenhouse for better control (all are grown in containers), but I never once smelled sour milk. I think it air dries so quickly that no odor can develop.

August 29, 2019	#6
Sherry_AK Tomatovillian™ Join Date: Jan 2006 Location: Alaska Zone 3/4 Posts: 1,857	It did. It did not "cure" the problem, but made it manageable. I was able to give the plants a little more space by moving them outdoors and sprayed at least every two days or more often if the rain washed it off. Of course, mine was on tomatoes and not squash. From what I read at the time, the powdery mildews are host-specific so the one on squash may respond differently. I'd say it's worth a try.

August 29, 2019	#9
Cole_Robbie Tomatovillian™ Join Date: Jun 2012 Location: Illinois, zone 6 Posts: 8,407	Peroxide will kill the mildew. I dilute the drug store 3% 2:1, end mixture 1.5%. It works really well but is not cost effective on a larger scale. There are a lot of other homemade fungicides that work, too, I'm sure.