Weird dark spots on new tomato

Sun Oct 02, 2011 11:57 pm

Noticed this today. This tomato (size of golf ball) came from a solar fire tomato transplant I planted 1 month ago. The other tomatoes on the same plant do not have these marks.

The dark spots are not soft either. They have the same texture/firmness as the rest of the tomato. I thought it might be blossom end rot but these dark spots are on the sides of the tomato, not the bottom. What's causing this?

Mon Oct 03, 2011 2:59 pm

How does the plant look, does it have black spots on it? Looks to me like the beginnings of blight, but I could be wrong.

Mon Oct 03, 2011 5:05 pm

Here's what the plant looks like, the white stuff is sand from the top soil.

Mon Oct 03, 2011 9:30 pm

It definately looks like blight. I personally would pull those plants that look like that up and destroy them. If there is enough time I would plant some new plants in another spot in your garden and put some calcium in the hole when you plant even finely crushed eggshell would be better then nothing. Then make sure you water from the bottom only, don't wet the plant. When the bottom leaves start to yellow, cut off all of the leaves that touch the ground or would get wet with careful watering. If it rains a lot you might consider spraying with a fungicide the cheapest of all is very strong chamomile tea cooled off then add 1T canola oil per gallon and spray early in the morning so the plants can dry. Note that is sulpher based, copper based ones work better. Whatever you do, start rotating where you plant tomatoes. They should not be in the same place more than once in 4 years and even longer if possible where they were blighted. Unfortunately, blight it more and more common and harder to control, some of the big box stores introduced it in the plants the sold a couple of years ago making the problem even worse.

Mon Oct 03, 2011 11:13 pm

I'd really hate to dig this plant up because it is producing nicely. Would using an anti-fungus/disease spray work? I've got tons of that stuff.

Tue Oct 04, 2011 2:18 am

It is blight or septoria or something similar. If I were you I would cut all the brown and yellow leaves and stems. It will slow down the fungus.

It can spread so if there are healthy tomato plants around it will spread to them if it gets in contact. This can affect other nightshade crops too so keep that in mind.

I had some tomatoes with this problem and just cut the bad parts off and let them produce tomatoes for me for another month until the tomato plants were done then I cut them down. But I did not compost them. When you cut them down don't compost them either.

Tue Oct 04, 2011 2:19 am

BTW none of my actual tomatoes got any fungus on them only some leaves and stems. I don't recommend eating any that have fungus on them like the one you pictured.

Tue Oct 04, 2011 3:25 am

I'll cut off the brown/yellow leaves and see what happens.

Fri Oct 07, 2011 10:23 pm

The dark brown branches/yellow leaves where cut off, and it seems that the rest of the plant thinned out a little. But there is a 2 ft. stalk with new leaves and blossoms growing out of the plant without any marks on them.

Is this a good sign for the plant? Keep in mind the heat's come back and we have very heavy rains for the next 5 days.

Sat Oct 08, 2011 12:41 pm

If you are having disease issues, you would be much better off to stake or cage your tomatoes up off the soil. Lots of diseases like septoria and blight are soil borne and get transmitted through contact with the soil (even soil particles that splash up on leaves from watering).

Those of us that cage our tomatoes usually remove all the bottom leaves, just so that nothing contacts the soil.

Sat Oct 08, 2011 2:47 pm

^lesson learned.

Fri Oct 14, 2011 10:38 am

rainbowgardener wrote:If you are having disease issues, you would be much better off to stake or cage your tomatoes up off the soil. Lots of diseases like septoria and blight are soil borne and get transmitted through contact with the soil (even soil particles that splash up on leaves from watering).

Those of us that cage our tomatoes usually remove all the bottom leaves, just so that nothing contacts the soil.

Actually none of the common tomato foliage diseases are soil borne naturally as are the many systemic diseases, and I'm referring to:

Early Blight ( A solani), Septoria Leaf Spot, both fungal, and Bacterial Speck and Bacterial Spot.

All new infections with those are by air and embedded in rain droplets.

What can happen is if plants with those diseases shed the spores or bacteria to the soil the next year there can be splashback infection after heavy rains or too much irrigation, as was mentioned above, and thus the lower foliage becomes infected and that spreads upwards on the plants.

So as was also mentioned above, taking off the lower branches can help, but again, all NEW infections are by air and rain and sometimes by irrigation.

But there are some ways of preventing air or rain borne foliage infections as well as splashback infections.

Spraying with a good anti-fungal ASAP when the plants are put out and keeping up on a regular schedule is THE best thing that can be done.

There are no very effective sprays available to the home gardener for the bacterial ones, although you can try a copper based spray. These days some folks are concerned about build up of copper in the soil.

No treatment is 100% effective so turning the soil over deeply at the end of the season, and a tiller doesn't do the job, can help bury those agents so they have a harder time of getting near the top of the soil to cause splashback.

Mulching plants also help to prevent splashback infection as well.

I grew far too many plants and varieties each season to ever think of caging or staking, although when I lioved in certain places I did make my own CRW cages and used them and here where I am now at one place I have used a few cages.

What was easiest for me b'c of the number of plants I was growing was to sprawl them and that worked very well indeed. A farmer friend would turn under my plants in the Fall, plant winter rye, and then in the Spring turn it under again and then plow and disc and smooth off my field.

Doing that I was able to use that field for tomatoes with much less disease problems, for about 20 years without disease buildup. And I had everything else planted in that same field as well, so doing that also proected the eggplants and potatoes which share some diseases with tomatoes, all being on the genus Solanum.

Hope that helps.

Carolyn

Mon Oct 17, 2011 10:46 am

It's nice to see you on this site Carolyn. I've appreciated your posts on other gardening sites over the years and have found your expert advice on tomato questions to be extremely helpful. Both your new audience and, your old fans, will be well served with your contributions to this gardening forum.

Mon Oct 17, 2011 3:51 pm

vermontkingdom wrote:It's nice to see you on this site Carolyn. I've appreciated your posts on other gardening sites over the years and have found your expert advice on tomato questions to be extremely helpful. Both your new audience and, your old fans, will be well served with your contributions to this gardening forum.

Thank you for that b/c my two cat kids give me NO feedback. :lol:

And now it's for me to figure out which person you might be from the NE Kingdom of VT, b'c there are two I know of. You must be the other one. :wink:

Carolyn