The tomatoes look a lot worse than this now. I've lost well over half the foliage in the last month due to the yellowing and dying off and my pruning of the yellow and dead. I also see some orange(bronze) in the leaves now. If this helps, there's also browning on the stalks.

hi woohooman,
I feel your pain. I'm lose my cukes and am losing my zuch to white flies (I think). The leaves get that same white look in your pictures then die. I've decided to remove the bush where we have the white fly infestation. No more live and let live. At least they have left my tomatoes alone.

Before I offer a bit of info, let me mention that when posting you would better help folks to assist you if you add your zone & geographic area (city or town would be good, along with the state, of course). Your "My Page" listing of "United States" is of no help whatsoever. Don't worry, we will not stalk you. :-)

It's powdery mildew on the cucurbits in the first two photos. This has been of epidemic proportions in a large part of the Midwest, in my garden and from what I hear from friends and correspondents in MI, PA and here in OH.

Looks like some sort of leaf miners in the last couple pictures, and blight on the tomatoes. Check the links in this earier GW post regarding tomato troubles, linked below.

As for the powdery mildew, here is some info from Ohio State:
POWDERY MILDEW DISEASES. Many plants are affected by powdery mildew diseases, with different powdery mildew fungi causing the disease on different plants. The most familiar way to recognize powdery mildew diseases is the actual "sign" of the powdery mildew fungus growing on the upper leaf surface. This powdery growth is a combination of asexual spores of powdery mildew fungi in combination with threadlike strands of the fungus called hyphae. The mass of this powdery mildew fungal tissue is visible to the naked eye, but individual spores and fungal hyphae are not; these forms of the fungus, capable of causing infection, are microscopic in size. One of the overwintering forms of the fungus are dark-colored fruiting bodies know as cleistothecia, that are visible as small round objects on leaves, resembling grains of pepper.

"Symptoms" (effects on plants from infections) of powdery mildew diseases are sometimes not recognized as being caused by powdery mildew fungi. On a plant like lilac, often symptoms are not apparent - all you see is the powdery white sign of the pathogen.
Control involves improving air movement and reducing high relative humidity, to the extent possible, with judicious pruning and plant siting and use of powdery-mildew resistant varieties when available. Also recognize that in many cases the disease causes little harm to plant health, though fungicides may be used when necessary. Common powdery mildew fungicides include: triforine (e.g. Funginex), thiophanate-methyl (e.g. Cleary's 3336), and propiconazole (e.g. Banner). Read and follow the fungicide label carefully when applying to a particular plant. Powdery mildew fungicides can be very effective because the fungal infection by powdery mildew fungi is very superficial compared to most fungal infections, with the fungus only penetrating into the epidermal layer of cells.
There are organic preventives (biofungicides) for powdery mildew, too, but as you will read, most, if not all, need to be used before the symptoms develop. See http://www.gardensalive.com/category.asp?c=15

Hope this has been helpful.

Here is a link that might be useful: Identifying tomato problems

strugglinggargener: I've managed to hold on to my cukes, squash, and zucchini with pruning measures. As soon as I see the mildew, I clip those leaves. But my yields on the cukes has dropped and new flowers look weak. It's amazing though...normally the squash and zucchini are the 1st to get symptoms, but they seem to keep trucking along and producing.

It's really the tomatoes that have me perplexed... they were doing SO good---and then in like the last month, they've gone to complete poop. I doubt I'll be able to save them(the only thing that doesn't have me completely irked is the fact that I planted 4 cherries a couple months later and I'll probably be able to go into deep fall with those).

weedlady: Thanks for the info--although I'm not sure about the blight. I guess I'll take a sample down to the master gardeners and let them do some tests. It's free. :) This has happened the last 2 years and rotation isn't the problem. I'm pretty sure the transplants were resistant also---home depot better boys.

Regarding more info on my location, how do I change the info displayed on my posts?

The little lines in the photos is the larva of any number to leaf piercing insect such as Sawflies. I just remove the infected leaves which disrupts the life cycle. There is nothing you can use to control the insects because the long gone while the symptoms appear. Make sure to remove all plant debris in and around the garden in the fall.

It seems like you have a whole host of problems.The first picture shows powdery mildew. Other pictures show leaf spot and maybe early blight. To top it off you may have whitefly. I'll bet you are in the part of the country that's had lots of rain and humidity.

While picking off the leaves helps you really have to spray with some kind of fungicide( a copper based one is best) but if you are organic I don't know what to advise. Get a barrier between the soil and the plant A heavy layer of newspaper and new mulch will help.

Most fungal diseases start in the soil. The rain hits the soil splashes on to a leaf carrying the spores with it. then it splashes on an infected leaf carrying it to a new leaf. the leaves die and fall to the soil and so on in a viscious cycle. You can't do much about the rain but don't wet the leaves when you water

Powdery mildew is, in my experience, easily controlled with sprays of either 1 teaspoon of baking soda mixed in 1 quart of water, or a 50/50 mix of fat free milk and water, sprayed every 5 to 7 days when the PM appears. There is no good reason to remove leaves affected by PM.
You do have plants that have had leaf miners and ther eis also no good reason to remove the leaves with those wee buggers tunnels. More often than not by the time we see signs of leaf miners the larva have already dropped to the soil to pupate, but if you do see one squiggling its way through the leaf just squish the wee bugger right there and leave the leaf to continue doing what plant leaves are supposed to do, manufacture nutrients to feed the plant.
Aphids can be simply washed off a plant with a strong spray of water, although because Aphids can have several generations on the plant before you are even aware they are there that needs to be repeated often.
It appears to me that there is not nearly enough mulch on the soil to begin to help the plants withstand stress which is the major reason plants are attractive to insect pests.

Thank you for the feedback.

oilpainter: Nope. No rain. Are You kidding me? LOL. I live in Southern California---it barely rains here, even in the winter. Humidity? A tad, but not nearly like the rest of the U.S. I did try the "spray off" method a few times as kimmsr suggested in the next post, but that's about it. I even clipped the leaves off the bottom foot of the tomato plants as was suggested by somebody to prevent soil borne illnesses.

kimmsr: I've tried the baking soda thing a couple times but don't see any improvement. As far as the mulch is concerned, there was quite a bit on the ground but it's been worked into the soil by cultivation.

I'll try to get more updated pics, so maybe some of you can give better diagnoses. The pictures I have here don't tell the story that's existing now. :(