Powdery Mildew or Downy Mildew or both?

[SQWIB]

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.

[applestar]

This is powdery mildew. Once the white “blooms” appear on the top surface, milk will not be enough — you need to up the ammo to something stronger.

Straight or diluted peroxide or baking soda (or potassium bicarbonate)/oil + liquid soap sticker solution would be next step up in my arsenal. (I’ve been using the potassium bicarbonate recommended by pepperhead212 as of last year)

Before treating, I first cut off all leaves with water spots when seen from underneath with sky in background. Those won’t recover. Particularly take care to remove infected leaves above fruits that will drip spores on them.

I follow a couple days later with strong-ish AACT dilution and/or milk-whey solution to re-establish foliage beneficial microorganisms, and alternate treatments if necessary.

Copper/Bordeaux mixture is an approved organic fungicide, but I haven’t tried using it. Neem oil is also fungicidal, but I’ve only used safflower oil or canola oil — needs to be light, refined oil. I use Dr Bronner’s liquid soap— tea tree or citrus when using in fungicidal solution though actual amount of the essence is minor.

[SQWIB]

Ok I have the Dr. Bronners Pure castille soap, peroxide and baking soda.
Can you please give me a mix to follow...

If I cut off the leaves with spots I wont have any leaves left!

[applestar]

I was given this recipe by an European gardening friend so it’s in metric —

1 litre 0,264 gallon
1 tablespoon rapeseed/canola oil(no suflower oil!) or another plant oil
...we concluded not to use Sunflower oil because my tomato seedlings in the garage were eaten down to stem stubs by mice...
...Canola oil was originally developed/pressed from seeds of patented/registered selection of rapeseed/mustard variety used for processing into Canola oil — still true today?

7,5 gram baking powder
1 splash washing up liquid
...in the USA dishwashing liquid is almost always detergent which can burn plants. We’ve had many discussions about this here on Helpful Gardener...

I mix a teaspoon denatured alcohol in it, the spray don't agglutinate

when the infection is very strong I mix 1 tablespoon hydrogen peroxide (H2O2) in it. (3 per cent)

Than you must spray daily - one week
...this was originally from a discussion about indoor plants, so I’m not sure if outdoor plants under full sun can take daily spray — I usually don’t spray more than once every 2-3 days and usually switch/alternate with act or milk solution after fungal infection run has been suppressed...

[applestar]

I’m having similar dilemma — I cut off all the heavily infected leaves hanging above the fruits yesterday. Definitely any in direct contact with fruits.

[applestar]

BTW — Considering the ingredients, this recipe will be an effective insect killer as well, especially with alcohol added. Definitely will smother/desiccate soft bodied, but most likely will smother flying insects as well, so be mindful of when and what you are spraying.

- Note also that his is oil-based and should be careful about exposing sprayed plants to direct sun and heat above 80~85°F especially on tender new growths -

- salt- and oil- containing solution can/will evaporate and become more concentrated — susceptible plants will be strongly affected especially on leaftips where the solution drips (especially true of peppers)


...there is a tendency to blast away when spraying fungal infected plants since you need to coat thoroughly both upper and underside of foliage ...


(milk solution and AACT are easier because there is no such restriction — though ideally they should be applied when it will be cloudy all day to avoid exposure to sterilizing direct sunlight — works great if you spray just before sunset when it won’t rain during the night ...by morning the bacteria will have formed their own mucus/biofilm to stick onto the plants and establish)

[SQWIB]

I think I'm more confused now.

Should I just spray with the milk solution, what is AACT?

1 litre 0,264 gallon
1 tablespoon rapeseed/canola oil(no suflower oil!) or another plant oil
7.5 gram baking powder (SPLITING A GRAM!!!) or is that 75 grams?
1 splash washing up liquid (WHAT IS A SPLASH?)
I mix a teaspoon denatured alcohol in it, the spray don't agglutinate (keeps the mix soluble?)
when the infection is very strong I mix 1 tablespoon hydrogen peroxide (H2O2) in it. (3 per cent)
Than you must spray daily - one week

I think I'm more confused now.

Should I just spray with the milk solution, what is AACT, or try the mix you provided



Dummied down for me? Does this look OK?

• 32 oz. water
• 1 tablespoon neem oil
• 1/4 oz baking powder or (1-1/2 Teaspoons)
• 1 oz. of Dr. Bronners Castile Soap or (6 Teaspoons) or (2 Tablespoons)
• 1 teaspoon denatured alcohol
• 1 tablespoon hydrogen peroxide

spray daily - one week
Does that look about right? Ill be making a batch Friday

[applestar]

LOLOL — I should have known you would want to be exact. I usually avoid splitting the gram by doubling the recipe, but I actually sometimes just weigh on digital scale until it flickers between 7 and 8 grams I also prefer to dilute more rather than go stronger/more concentrated.

I think a “splash” is probably a “squirt” = 1/2 to 1 tsp. Everything else looks about right.

...as with most home mixed solutions, be sure to shake well between spraying...


BTW I don’t like to recommend to other people about a method that I haven’t tried myself in a while, so I went ahead and sprayed my own melons this morning while they were still wet with dew and in the shade (and bees hadn’t arrived yet ...and there were no treefrogs as far as I could tell ). I used Canola oil and half Potassium Bicarbonate, half baking soda (I ran out of KHCO3). I did find a spotted cucumber beetle hiding between leaves and thoroughly sprayed it until it stopped moving

I tried spraying some leaves that had obvious watery spots of the kind I mentioned without removing them — those are absolutes coated with white fuzz on the top surface and needed to be sprayed for a while for the solution to soak in . I also sprayed some leaves that were spotted with white but had not developed the watery spots. I will try remember to check if they show any signs of recovery day after tomorrow. (I won’t be spraying tomorrow though.)