[b54red]

Originally Posted by chlorophile

Thank you all so much for taking the time to reply to me. I learned a few things and it definitely helped me to figure out what it is. I think it is indeed gray mold and septoria throwing a 1/2 punch at these plants. I've dealt with EB and septoria every season but have never seen it move so quickly before. Then again, I have not been keeping up with my preventative sprays this year due to some family tragedies and personal health issues. That coupled with the wet nights and humidity have created the perfect opportunity for fungal diseases to take over.

I did not know that 'black' varieties are more susceptible to gray mold, but it makes sense. Last year I planted a black cherry in a container due to running out of space in the garden, and it was plugging along really well until it was struck with a nasty case of gray mold. It had the obvious symptoms - darkened petioles with girdling and dark/fuzzy leaflets. I was puzzled given my relatively decent upkeep, but I did read in a few places that black cherry seems prone to gray mold.

I assume Paul Robeson is also a 'black' variety (?) As I mentioned previously, the other plants that took a beating were Berkley tie dye, brad's atomic grape, and now I'm seeing it hitting the black cherry. My sungold, better boy, and early girl are all fighting the good fight against septoria and EB, but as has been my experience with hybrids, they seem to be doing much better with it than the heirlooms. They are definitely not happy, but I'm not flat out watching the plants turn to a dried mess in a short time period.

It seems that all these issues arise once the plant is loaded with fruit every year, which is pretty much late July here on the CT shore. Are there any studies regarding the (if any) physiological changes in tomatoes that create the window of opportunity for the fungal diseases to start hitting hard? Is it just the natural cycle of these organisms and unrelated to the plant's cycle? I assume the plants become 'stressed' when trying to ripen dozens of fruits and continuing to put out new foliage, but I'm curious as to the biochemical nature of these changes. It's also possible that it's only been my own experience that the fungal diseases don't show up until this point and hit others much earlier, but in my 4 years of gardening it's the same period, almost like clockwork. N=4 isn't particularly notable but definitely a trending result. I would think the fungal spores are present from day one and the onset of illness is related to either than plant's stress response or particular weather pattern, but I'm really just speculating here. I'm a biologist and need to know these things. Haha.

Again, thanks for all of your input. Bill-special thanks to you for your bleach spray thread-I used it last year to save a precious charatenais melon vine

I hope you're all having a great season.

Dave

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I agree that most diseases make the most dramatic appearance when the plants are fruiting and I would guess that the plants are stressed by that and the added heat. Throw in some rain and humid weather and you are ripe for diseases. That is one of the reasons that I like using a liquid fertilizer through a hose end applicator. It allows me to keep feeding the plants during that time when they are most stressed and I think it helps strengthen the plants and it also aids in them setting more fruit further up the plants.

I have some plants that I set out the 6th of August that have already had their first bleach spray due to gray mold showing up on a few of the lower leaves on the black varieties and they certainly don't have any fruit set yet. I find it is far better to react quickly to the first signs of gray mold and not wait. If you hit it as soon as it shows up with the bleach spray and keep the plants sprayed with a copper spray every week it can be controlled unless you get some really extended rain. Even then gray mold can be controlled if you go out between rains and spray the bleach spray every few days. Doing that as opposed to waiting for the rains to stop will greatly reduce the damage that you will have when they finally do stop. That also helps with Septoria which can spread like wildfire during those rainy wet periods.

Good luck.

Bill