dnonwoo
Newly Registered
Posts: 7
Joined: Tue Jun 29, 2010 12:01 pm
Location: Los Angeles, CA

Please help ID brown spots/white patches (with pics)

Hi all!
I've been growing persian cucumber and patty pan squash in containers on my back porch. The yield has been massively successful, but I've started noticing an increasing number of shriveled cukes and pale sad-looking squash, as well as wilted leaves. Most recently, the cucumber has developed obvious brown spots on the leaves, while the squash leaves have developed white patches. Any clues as to what's going on with them and what to do about it? I'm a complete novice to vegetable gardening, so even the most obvious advice will be helpful :)
Thanks in advance!

Cucumber:
[img]https://farm5.static.flickr.com/4097/4743919791_37e328f351.jpg[/img] [img]https://farm5.static.flickr.com/4139/4743922073_957d72be68.jpg[/img]

Squash:
[img]https://farm5.static.flickr.com/4121/4744559662_c450281a68.jpg[/img][img]https://farm5.static.flickr.com/4074/4743921293_2dde788929.jpg[/img] [img]https://farm5.static.flickr.com/4135/4743920689_46f4715632.jpg[/img]

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rainbowgardener
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Posts: 25279
Joined: Sun Feb 15, 2009 6:04 pm
Location: TN/GA 7b

I don't know about the brown spots. The white patches are most likely powdery mildew. It's a fungal infection that squash are pretty prone to (though it affects a variety of other things as well; in my yard bee balm and lilac are also prone to it).

Couple of things you can do for it (one or the other, not both at once, they would tend to cancel each other out:

Milk solution:
Dilute milk 50:50 with water. Add a tablespoon of yoghurt with active cultures and let it sit at room temperature for a few hours to culture the lactobaccillus. The lactobacillus is a fungicide that destroys the blight/ wilt fungi. Strain and spray on the affected plants, being sure to get the underside of leaves, leaf axils, etc.

If you have nearby unaffected plants, particularly of the same variety), I would dilute the solution down more and spray it on them preventatively.

Baking soda solution:
1 tablespoon of baking soda
½ teaspoon of liquid soap
1 gallon of water

Be sure the soap is soap, not detergent, which can harm your plants. (Dishwashing liquid is usually detergent. Dr Brunner's, Murphy's oil soap, Ivory soap, etc)

These treatments are general anti-fungals, so if the brown spots happen to be a different kind of fungus, it will work against them too, but I don't know that.

dnonwoo
Newly Registered
Posts: 7
Joined: Tue Jun 29, 2010 12:01 pm
Location: Los Angeles, CA

Thank you so much for the response! I tried the baking soda solution because it's something I could do right away. I used my kitchen Dial - hope that's proper soap.

I used most of a 32oz spray bottle for 3 plants total (1 squash, 2 persian cucumbers about 5' tall each), is that enough? I feel like I was spraying for a good half hour and needed to stop. Also how often do I need to go through this process?

A final question: While I don't doubt that both might have some kind of fungus, the cuc ailment seems different from the squash. The squash at least is still producing, while the cuc has entire branches that are going yellow, and not a single fruit is looking like it'll make it (they grow about 1", turn yellow, and shrivel up). While spraying, I found tiny creatures on the undersides of the leaves. They look dark green to black, oval bodies, hang out in groups, seem to be making more (gah!). Picture below - sorry it isn't the best quality, can't find my camera and phone doesn't do close-ups well. Anyway, any thoughts? Aphids? Will the soapy water spray-down take care of them too?
[img]https://i65.photobucket.com/albums/h234/dnonwoo/4752441806_cee85fa518_o.jpg[/img]

Thanks again!
-d



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