Kitchen Garden Forum

My greenhouse tomatoes are about 4ft tall, and have 5-6 trusses on them. The lower trusses have set well, and the fruit is growing. The tips of the leader shoot leaves are going brown, and the whole shoot then withers. I have let the side shoots on the top leaf axils develop to replace the leader, but they too are dying back. I had similar problems last year, the next stage was that the top trusses did not set, and the flowers dropped off, breaking off from the knuckle just behind the flower.(this has not happened this year - yet) Anyway, last year they all got blight , so it didn't matter.I'm growing several different varieties including some grafted ones, but they are all similarly affected, Apart from the tops, the plants still look really healthy. I'd be very grateful for any ideas.
Thanks.

Hello Peter.
I wondered when someone would make a posting about this, it has happened to me for the first time this year. Some, but by no means all of mr greenhouse tomato plants have been affected by what you describe. The only thing I can put it down to is excessive heat/sun that most of us experienced a while ago. One of my two greenhouses is partially shade by a Kentish cobnut tree/bush, and the plants do not seem to be as affected as the other more exposed greenhouse. Like you, it does not seem to hve affected the rest of the plant or any fruit on them. Indeed, some of them seem to have made a bit of a recovery.
Regards, Essexboy.

Hi Essexboy
Thanks for your reply. In a way I hope you're right, especially about the recovery bit. My worst affected plants are directly beneath the opening lights, I don't know what significance that has. Perhaps some shading like painting the roof with coolglass, and regular damping down in hot spells would help. Always wise after the event!
Regards Peter.

Hello Peter
Tomato plant growing points are very susceptible to weedkiller damage especially from the systemic types like Roundup. Even if someone has been spraying nearby you could see the effects on your plants as traces of spray drift in the air. The growing tips curl up and may turn yellow but this is not the symptoms you describe. However as your affected plants are below the opening lights could it be spray drift?

John

What are they growing in? I would suspect some of these new fangled bags that are a blend of anything that holds water. Get back to peat!

Hi John,
I would possibly agree with your posting if these Tomatoes were growing outside but it think it quite unlikely in a greenhouse.
My initial thought was that it was caused by sun scorch and having considered it further I am still of that opinion.
JB.

I usually have some plants which show symptons as described. This year a couple of San Marzano and a couple of Euromoney have set bottom trusses but the tops are shrivelling and dying back with little sign of hope of recovery. I am letting low sideshoots develop - in past years these have sometimes taken over quite healthily, sometimes not.
What it is I don't know. I am pretty sure what it isn't [in my case at least].
The tomatoes are in the polytunnel.

It isn't blight - none around at the moment this year.
It isn't weedkiller - I don't use it and in the highly unlikely event of anyone nearby spraying there is no chance of it entering the tunnel above the plants.
It isn't the growing medium - that's border soil and garden compost.

It could be scorch, but I think that is less than likely as surrounding plants are 100% healthy.

I remain puzzled - will try to post some pictures tomorrow.

Hi Alan,
It would be super if you could post some pictures. A picture tells a thousand stories. (well a few stories at least!)
Not all plants react the same to sunshine and in tunnels where the heat is very concentrated and comes down in a kind of blanket, scorching is still my main culprit. Scorching not only burns the tops but destroys the top structure of the plant and then rot sets in. Certainly by allowing side shoots to take over as the leader is one way around the problem. Lets hope that this works because it does it really means that scorch is the problem and that no disease exists.
JB.

This is really interesting. I've used a new super rich compost from B & Q this year and for the first time ever some of my tomatoes have done exactly what you describe. The funny thing is that it seems to affect some varieties and not others even they are all treated the same.

I'm pretty sure it is something in the compost that is either too strong or doesn't suit them. I've been giving the worst affected ones extra water and not feeding to try and flush it out and two of them are sending out normal looking new growth from the top.

They haven't been exposed to herbicides and they can't have been too hot as the majority are normal.

I won't be using that compost again.

Hi Johnboy

Thanks for your continued interest.

Peter, Essexboy, Plumpudding

Do your tomatoes look anything like my pictures below?

These three are an affected San Marzano - three out of eight are showing these signs.







For more pictures go to next post

Hi Plumpudding,
Yes it is very interesting. There are so many variables as regards the cause. May I enquire what this super compost from B&Q is and what is it that makes it so?
JB.

...and this is one of the unaffected plants immediately next to the affected one in the last post.



The final one is an affected plant of Euromoney showing the damage and the perfectly OK bottom truss/es.



Any comments very welcome.

It's not blight, it's not bought compost or manure, it's not weedkiller.

Hello Alan, Actually, mine do not look like the ones in your pictures! The affected leaves/plants have gone a uniform pale grey, not a midewy grey if that makes sense, the variety in my case are Alicante, been growing them for years with no problems like this. as I said before, the rest of the plant and any existing fruit do not seem to be affected.
Regards, Essexboy.

I wonder if Steve or Emma from K.G.Magazine could give us their thoughts on the suject.

Thanks to eveyone who has shown an interest in this.
For now, I'm ruling out compost problems, all my toms are in the same stuff, anly some are affected. Weedkiller damage is possible. My neighbour uses glyphosate under his electric fences, but he's a long way away, I don't think he has sprayed yet, and he uses a coarse spray like a watering can,so there shouldn't be much drift. Scorching is also possible, but why are side shoots coming later affected in a similar way? That surely indicates trouble from within the plant. I'll try to attach a picture of early stage damage.
Peter