Dreaded Tomato Blight
Leggi
Posts: 489
I've seen the beginnings of blight on one of my tomato plants which is planted in the ground, the main stem is quickly turning black. The plant itself isn't heavy with fruit and has just a couple of medium sized toms which are far from being ripe and a few new flowers brought on by the slightly warmer weather over the last few days.
Question is how effective is Bordeaux Mix, and is it really worth it for a plant which has so far produced so little?
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Have you got other tomato plants which are clear so far? If so I'd put a binbag over the affected plant, pull it up, seal it in the bag and get rid of it somewhere, to try not to affect the others. If the stem is already affected I wouldn't hold out much hope for it.
I've got 6 Marmandes and 7 Red Alerts in pots outside - the Marmandes have got a few well developed fruit and a lot of flower, and for the last week I've noticed a few small signs of blight on some leaves. I cut them off immediately, seal them in a plastic bag and they go in the bin. I've moved the plants so that there's more distance between them and check them 3 times a day removing any affected leaves and keep all my fingers crossed. So far so good.
It's so annoying 'cos in goodness knows how many years of gardening, these are the best looking tomato plants I've ever grown - so far, and in such a rotten year too!
The Red Alerts, which are next to the Marmandes, are showing no signs of anything - so far!
It was planted in a large raised bed with one other tomato plant with plenty of room around it and hardly ever (I think pnly twice actually) watered. I thought the one next to it was ok but having just had a look it does appear to have it too, I've pulled up the first one and cut off the infected parts on the second. Will keep a close eye on it as you suggest.
It's so disheartening when you grow things from seeds and care for them for so long to have to pull them before they've produced a single tomato. Poxy blight, but on the plus side I may have a new flower bed to plant up and the 6 or so tomatoes growing in the front garden seem fine.
Thanks for your advice Dove.
Bordeaux Mix can be effective - it depends on whether or not you want to use it. On the plus side, it is accepted, I believe, by the soil association as being organic. But it's still a mix of copper etc that you may prefer to avoid.
Personally, I have used it successfully in the past. At the first sign of blight, I cut out all affected parts, sprayed with Bordeaux and made sure that all the fruit that was subsequently harvested was well washed.
It is called Bordeaux mixture btw because it was first used in the vineyards on Bordeaux. The blue colour was also designed to deter casual grape pickers from stealing the ripening grapes. (Or so I read somewhere - could just be an old wives' tale of course
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Leggi, if the stems are quickly turning black it sounds like it could be Late Blight. If so, there's no saving the plant.
In general, spraying once any fungal disease symptoms are already present is a waste of time and money. It's too late. Spraying has to be preventive, meaning you spray before the spores arrive, starting a couple of weeks after planting out, then weekly or so afterwards, respraying if it rains.
Spraying doesn't guarantee you won't get fungal disease but it gives you a solid defence.
Dove - good luck!
Thanks Italophile
I've just been reading this http://www.harrowinleaf.org.uk/tomatotrials.html
very interesting.
Thanks, I think I may have to start regularly spraying them next year then. This is my fifth year of trying to grow tommies and my fifth year of blight. I've done all I can think of, not watering at all unless the plants wilt, changing the soil they grow in, giving them more room to grow (raised bed went from having 6 plants in it a few years ago to two this year) and trying to grow them in different parts of the garden has lead me to trying some in the front garden this year.
It appears that blight seems to be a problem in my area so I will just have to keep spraying if I ever want a good crop of home grown tomatoes.
This years crop so far - half a cherry tomato.
You're not crossing enough fingers!
This morning two of my Marmandes have black patches on the main stems
As soon as OH is up and has had a cuppa, I'll get him to move them away from the others (I slipped a disc last week 
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Although one of them is the only one with large toms on so far, I think I shall have to bite the bullet and bag and bin them in order to protect the others - oh it's fun this gardening lark, isn't it?
Dove, it is interesting, but a pity they just use the generic term Blight. They really should be identifying the pathogen(s). Anyway, the results are unsurprising. Once the spores are in place and doing their dirty work you can't (so to speak) kill them. Any anti-fungal action must be preventive.
Can you post a couple of photos - stems, foliage, fruit - before they go to Tomato Heaven?