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Re: Early Summer bits and bobs - 2017

Posted: Wed Jun 28, 2017 12:39 pm
by Colin2016
What are the conditions to great a blight warning?

Re: Early Summer bits and bobs - 2017

Posted: Wed Jun 28, 2017 12:48 pm
by KG Steve
It needs two consecutive days above 10C and with 6 hours in each of those days with a relative humidity of 90% or above to create a Hutton Criteria (formerly the old Smith periods which we learned about at college many moons ago).

Re: Early Summer bits and bobs - 2017

Posted: Wed Jun 28, 2017 12:58 pm
by Colin2016
Thanks Steve....Is there anything that can be done for to help plants get over it?

Re: Early Summer bits and bobs - 2017

Posted: Wed Jun 28, 2017 1:14 pm
by KG Steve
Hi Colin. Unfortunately as other forum members will tell you, potatoes and tomatoes with blight usually succumb very quickly and the old copper-based fungicides that used to offer some protection are now banned. Choosing blight resistant varieties such as the Sarpo potato range and tomato varieties such as Mountain Magic and Crimson Crush can help, although they are not immune. You need to watch for new developments however and to update to new varieties as they arrive as blight quickly mutates and overcomes resistances that have been bred into our crops.
Tomatoes/potatoes in a greenhouse/polytunnel are usually less at risk since the covering helps protect them from the spores. This usually works for me, although I know plenty of gardeners who have had blight undercover, too!

Re: Early Summer bits and bobs - 2017

Posted: Wed Jun 28, 2017 3:18 pm
by Geoff
The copper based treatments originated in the wine industry hence Bordeaux mixture. I recently saw something about a new vine fungus treatment that has been developed I think in the UK and is supposed to be harmless. I have Googled but failed to find anything to link to. I wondered if you have seen anything in the technical press to suggest it could have other uses?

Re: Early Summer bits and bobs - 2017

Posted: Wed Jun 28, 2017 3:26 pm
by KG Steve
Nothing at the moment Geoff and certainly not for use by we amateurs, but I'll keep my ear to the ground.

Re: Early Summer bits and bobs - 2017

Posted: Wed Jun 28, 2017 3:49 pm
by Pa Snip
Just returned from quick visit to plot to raise my 2 marrow fruit contenders off of the soil.
Whilst there I noticed one of the 2ft tall Gardeners Delight tomato had a complete set of yellow leaves at the top, further inspection revealed the all to nasty indication of blight. The main stem and side shoots had brown blotches some of which were turning to black.

Plant swiftly removed and disposed of off site. Washed hands before handling anything else.

Re: Early Summer bits and bobs - 2017

Posted: Wed Jun 28, 2017 3:55 pm
by KG Steve
Well you have the honour of being the first among us Pa Snip, but not the last!

Re: Early Summer bits and bobs - 2017

Posted: Wed Jun 28, 2017 4:04 pm
by Pa Snip
Thanks Steve,

Given a choice I would have passed up that honour. Now its keep an eye on the spuds and rest of toms

Re: Early Summer bits and bobs - 2017

Posted: Wed Jun 28, 2017 4:46 pm
by robo
I had it last year in all my tomatoes this year I bought seeds that had been advertised as blight free but I have grown three other varieties as well I'm hoping I'm blight free this year

Re: Early Summer bits and bobs - 2017

Posted: Wed Jun 28, 2017 7:12 pm
by Primrose
Pa, that,s strange. We're only a few miles down the road from you but no blight warning received here. That's strange. I wouldn't think climatic conditions were that different over such a small area.

Re: Early Summer bits and bobs - 2017

Posted: Wed Jun 28, 2017 8:23 pm
by Westi
Not got one yet down here!
Fingers crossed I can get through the week as no point spraying as it would wash off as the rain has been consistent without a fine break of more than 20 minutes! Not complaining - plot needs the rain.

Re: Early Summer bits and bobs - 2017

Posted: Wed Jun 28, 2017 8:28 pm
by peter
When and why did it change from a Smith to a Hutton?

Re: Early Summer bits and bobs - 2017

Posted: Wed Jun 28, 2017 8:54 pm
by Westi
Hi Peter!
I thought the same & did some research, posted the "research" on here! (well somewhere on here)! Named after the university/person that did more research into the conditions that led to the big blight in Ireland, but so far I've not been impressed & I know I may well eat those words, but found the other alerts did come with the expected results, not as much warning but there was a window of opportunity that was just enough & now I feel I am being conned to spray without the the certainty that it will occur!

Could I be controversial & ask who sponsors Blight Watch? OK! Naughty! Fortunately have a bit of a supply of copper spray but won't last long if I spray at every alert now days!

Re: Early Summer bits and bobs - 2017

Posted: Wed Jun 28, 2017 9:27 pm
by Pa Snip
Primrose wrote:Pa, that,s strange. We're only a few miles down the road from you but no blight warning received here. That's strange. I wouldn't think climatic conditions were that different over such a small area.


I find the whole set-up strange.

I don't believe the problem relates to just today as a couple of days ago I did notice slight changes in the stems but not such as gave cause to think blight at that stage.

As for the fact we are located closely and yet you got no warning today, we have remarked upon differences in weather in the past. It is quite baffling