Gray mold and black tomatoes

[b54red]

After absolutely no gray mold last year when our humidity was unbelievably low with drought conditions, it is making a comeback. As usual it started with JD's Special C Tex a black variety that over the years is usually one of the more susceptible varieties to gray mold. For a few weeks now we have had very little real rain but we have had a number of light showers or drizzly periods and recently the humidity has gotten very high so I was watching my plants closely for it to show up and despite weekly spraying with both Daconil and copper it got started on my JD's.

I sprayed with the dilute bleach spray yesterday late in the day and for the next day or so will watch and see how bad the infection has spread. I went ahead and sprayed all my plants since I am also having quite a bit of Early Blight and hope it will help that a bit. I saw no signs of it on any of my other tomatoes but the spray with the diluted bleach will tell me for sure.

I grow several black varieties each year and most seasons they are all hit by gray mold to some degree. I have only seen it spread to other red or pink varieties once and that was a very rainy summer with plants growing out of control because it was just too wet to take care of them properly and even then only a couple of plants other than the black varieties got mild cases of gray mold. I have found that spraying with a copper spray will help greatly in reducing the chances of gray mold getting a good foothold on plants but even that doesn't work when conditions are ideal for it to spread. As long as I take quick steps to stop it the problems it causes are mainly just losing some foliage from the diseased leaves after spraying with the diluted bleach spray. A day or two after spraying those leaves will wither up and be removed and I will follow up with a copper spray as a preventative. Sometimes this process has to be repeated several times through the season but usually if I am diligent with treating them it can be kept under control.

If any of you are growing black tomatoes in an environment that isn't very dry then keep them sprayed with a copper spray and keep an eye out for the first signs of gray mold. If it does show up treat it as soon as possible. If it is very minor then the copper may take care of the problem but if it is showing on more than one or two leaves I recommend the diluted bleach spray be used late in the evening or early in the morning before the sun is on the plants. Waiting will only worsen the problem and if it get too bad there is just no stopping it. The varieties that have shown the most vulnerability to gray mold for me over the years have been Black from Tula, Black Krim, JD's Special C Tex, Carbon and Berkley Tie Dye Pink but I have never grown a black variety that hasn't gotten gray mold at one time or another.

I love the taste of most of the black varieties that I have grown and with a little extra work they can be some of the most productive and tasty varieties especially in hot weather but I can never drop my vigilance especially when it is wet or humid.

Bill

[KarenO]

Maybe try Polaris. Seems very hardy and tolerant.
KarenO

[decherdt]

I'm finding Cherokee Carbon F1 to be the first and most susceptible here, despite weekly bleach spray with next day fungicide. The 2nd most susceptible is Black Cherry which has seldom ever had any troubles. They are still in better shape than any year previous. Bleach water tonight and tomorrow am, then zero day PHI fungicide + BT Sunday morning.

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