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7 messages
05/09/2012 at 02:26

I have had tomato blight in the greenhouse for the last 2 years.

Can you tell me if and what treatment i should use to avoid it happening again

05/09/2012 at 11:20

My greenhouse tomatoes have blight now and again, but its best to water regularly and feed once a week and always keep the greenhouse ventilated.  The weather this year has been terrible for tomatoes, either too cold and wet or warm and humid!  I always keep the greenhouse door open slightly and with the roof vents this usually keeps the greenhouse air circulated. Hope this is of help Jen2.

05/09/2012 at 11:36
Jen 2 wrote (see)

I have had tomato blight in the greenhouse for the last 2 years.

Can you tell me if and what treatment i should use to avoid it happening again

Unless you want to spray preventively against fungal problems, all you can do is basic housekeeping. As WD says above, ventilation is a fundamental. More the better. Air circulation is a big help against the fungal spores settling on foliage. I've known people to keep an electric fan set on low to keep the air moving.

Beyond that, keep as much space between tom plants as possible - at least 3' hopefully - and try to avoid great wads of foliage developing on plants by judicious removal of branches and leaves. The thicker the foliage, the less the air can circulate.

Never ever wet the foliage. Damp foliage is heaven for fungal spores.

Try to keep a gap of about a foot between the lowest foliage and the soil. Fungal spores can and will fall from the foliage to the soil underneath and they can splash back up again when watering. The gap helps against this.

The problem with greenhouses is that the closed environment can be an incubator for diseases. That's what you have to work against.

05/09/2012 at 12:12

I know this won't be of any help to you Jen, but on last Friday's Gardeners World, even Monty Don had lost most if his Greenhouse crop to blight. It seem's no-one can be spared, even the experts.

05/09/2012 at 13:44

Jen when all around me have had blight the last few years I have not had any, I put it down to everything being in pots on gravel with no soil in the borders.
Each year I use a power washer which will take a soap wash and soap it all over then up the power and wash every bit of glass gravel and pave, an hour well spent.
It is a wall mounted greenhouse on a South facing wall so I put in extra vents and also use a fan when needed, of course I am retired so can be there to do what is needed people working can only take a chance on leaving vents and doors open or a fan on a thermostat, costly probably but better than losing your crop.
The blight is windblown and can strike in hours, once it hits take out the plants and burn or green waste them and you may save some of the other plants, no guarantee although worth a try.

Frank.

05/09/2012 at 15:57

The ventilation is the key. As to removing the plants completely, it depends on which pathogen has struck.

If it's Late Blight, definitely get rid of the plant ASAP. If it's a more common and less destructive pathogen like Early Blight, Septoria Leaf Spot, or even Leaf Mould, one of the very common problems in greenhouses and just about unique to greenhouse toms, you can keep it in check by removing and destroying affected foliage as soon as it appears. These diseases don't ravage plants to anything like the extent that Late Blight will. In fact, with care, most plants will live a normal, productive life.

06/09/2012 at 00:19

thank you every one for your tips on tomato blight in the greenhouse

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