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This year I thought I would use an organic slow-release fertilizer to boost my plants and because I thought it would be more goof resistant then other types of fertilizer. When I first started using the organic fertilizer on my tomatoes ( using tomato-tone) and flowers (using flower tone) the fertilizer seemed to help however now the plants seem to be dying. The leaves are turning yellow with brown or white spots. It seems to look different on different types of plants but have very similar characteristics. I can’t see any parasites (bugs) and treated some of the plants for parasites (bugs); Yet there was no noticeable difference on the control group that I used insecticides on; so that seems to rule out parasites (bugs). I am somewhat skeptical that it’s a virus or bacterium because it has affected a wide variety of plants (tomato plants, Cardinal vines, marigolds, impatiens). Celebrity tomatoes seem largely unaffected; yet my supersweet 100 tomatoes are in dire straits and liable to be a loss for the rest of the year. Several of the marigolds have completely died, while some seem fairly unscathed.
I’ve watered nearly every day and on hot days often twice a day. The weather this summer has been rather unusual in that it hardly ever got above 90°F. For the most part it was an unusually cool and wet summer in this area (Cincinnati, Ohio).
I’m wondering if the tomato-tone and flower-tone might be the problem? Perhaps I’m over fertilizing or need phosphorus and/or potassium?
I’ve tried using sulfur dust on a control group of supersweet 100 cherry tomatoes but they seem to show no signs of improvement.
The tomato plants have practically stopped growing and for the most part aren’t producing any new flowers; yet most of the tomato fruit seems to be healthy and continues to ripen. It’s near the end of the growing season here anyway to make much difference; but I would like to learn so that perhaps I can stop this from happening again next year.
I’m poor and can’t afford a decent digital camera so I just picked a few leaves and put them on my scanner, one up and one down.
It's probably a fungus. My tomato plants looked like that the first year I grew them in California--my plants were not in a sunny enough spot and one rain did them in in the cool weather. I'm not sure which fungus, but if I were to guess, I would say you have a combination of different fungi infecting your plants.
Tomato plants don't like too much water, too much shade, or too much cool weather. I don't know about the fertilizer you used, but it sounds like you were watering them too much, especially for the cool wet weather you had this year. If you happened to water the leaves, or let the stems and leaves touch the ground, that's a good way to invite fungus to infect your plant. Even more so if your plants weren't getting enough sun.
Here in Seattle, I water each tomato plant only once a week when it's below 90 degrees. When it's above 90 degrees I water them twice a week. I water each plant on low hose setting (just enough water to make a steady stream) for 20 minutes at a time. Infrequent long slow deep watering of the roots is how tomatoes like it. This infrequent deep watering not only helps prevent fungus, but it also causes the plant to put more energy into making fruit and less energy into growing leaves. You can also dig a bowl around each plant (preferably before transplanting the seedlings) and fill the bowl with water to water the roots. It also helps to loosen the soil at least a foot down (2 feet if possible). I don't use any fertilizer myself--just 1 to 2 inches of good compost on the soil. It's been warm and sunny in Seattle this summer, and my plants are healthy and fruiting like crazy this year using this method.
Any fungus gets your tomatoes good it will hinder the growth of the plant. Fusarium wilt (sp?) is the most serious fungus that can infect tomato plants (and other plants) because it stays in the soil for over a year, and thus infect susceptible plants that are planted there the following growing season. It doesn't sound like you have fusarium wilt from what I've read about it, but I wouldn't rule out the possibility until you've checked up on it.
also, i've fount the tomatoes do better watering 1 or two times a week - soaking - rather than daily.. a lot of the diseases like moist soil - and many splash up onto the leaves.. sorry i' am no great disease identifier.. if it gets bad i spray .. i prefer volume over organic quality when it comes down to a choice.
-joe-
I may have a similar problem (see image), and I suspect too that it may be from fertilizer? I bought an "earth box" which came with it's own bag of fertilizer and dolomite, to be used with potting soil when the box was originally set up. Over time, more and more leaves began to look unhealthy with little white or yellow spots, eventually turning the whole leaf yellow and then dying. It doesn't look like any of the bacteria or fungal infestations that I've read about. If any expert people can shed some light, please do!
