blight watch 2012

[farmer jon]

anybody reported any sightings of potato blight yet ? up here in north of england the forecast is for 3 days heavy rain with relative humidity dangerously high in the nineties at times. if the wind drops & temp holds up at night then it is looking ominous. I have good growth on mains & seconds so will give a spray tonight to be safe. canopies are closed over the drills so need the breeze to keep the air moving. would advise anybody to ensure their potatoes are clear of weeds to help with the air flow.

[Kleftiwallah]

I think I might have a bit more than a touch of blight. North Wiltshire.
If it isn't raining too much tomorrow the few affected are coming up. Pentland Javelin.

Cheers, Tony.

[peter]

A few warnings for my area.

[Colin_M]

Quite a few of my Charlottes have got brown patches on the leaves & overall growth looks like it has slowed down. My Maincrop however look fine & vibrant.

I'm near Bristol.

[Colin Miles]

My Charlottes here in Carmarthenshire looking fine - checked this morning. Also those and other varieties on the nearby allotments. But obviously need to keep an eye on them.

[Geoff]

Perhaps one of the professionals will answer this. I'm also getting these Blightwatch emails based on humidity and temperature statistics but is there really a risk this early in the year? These conditions in a month's time maybe, but now?

[farmer jon]

unfortunately blight can occur anytime from late may onwards. it usually happens when the temp is 10C or above for 48 hours & a relative humidity of over 90% for at least 11 hours each day.this is known as the "smith period ".
we usually associate blight with the hot sticky nights of late july /early august, usually when the wind falls calm after thunderstorms. it is the wetness that is causing the problem so early in the season this year. wish we still had dithane 945 in our arsenal !

[donedigging]

I have also got quiet a few brown spots on the leaves of my earlies...Belana, never grown them before and quiet disappointed with their harvest.
Second crop, Harmony looking good and in flower and growing well

[Geoff]

Thanks for those words of comfort Jon. Watching the Countryfile forecast last night this week looks like a Smith period. I suppose I shouldn't admit to having some Dithane in stock.

[Chantal]

Can I ask if there is more than one strain of blight?

Last year my plot neighbour and I had some tomato blight, but not much. Sounds insane as usually one blighted tomato can wipe out the whole crop in days, but this was very odd.

We found maybe 50 tomatoes (in total) mixed in with healthy tomatoes on his plot and I had only a dozen or so out of thousands. We are both certain this was blight, we've seen it often enough. Brown lumpy tomatoes etc, but the leaves were largely unaffected except around the dodgy tomatoes and healthy tomatoes were on the same plant.

Anyone got any ideas as last year, having found some blighted ones, I picked the majority of my crop and ripened them indoors. I found the odd brown blighted tomato in them too, but only the odd one or two. I don't want to panic and pick early again if I don't need to!

[realfood]

Yes, there are several strains of blight. some potato varieties which had some resistance to the older strains of blight, can succumb to the latest strains.

[oldherbaceous]

Last years blight was definitely not as bad as the previous two.
As blight is always changing, some years are a lot worse than others.
So hopefully it will be another weak strain this year.

The part i'm not sure about is, early and late blight, is the early version weaker because the smiths period doesn't rear it's ugly head as much?

[Chantal]

Rugby area had another Full Smith Period yesterday, the third this year. Luckily not back to back, so no blight yet, but it's very humid again today

[Chantal]

I spoke too soon. I've just had another message from BlightWatch that we've had our second and consecutive Full Smith Period.

[oldherbaceous]

Dear Chantal, "gosh it seems a long time since i wrote that" all you can do is keep your eyes peeled, and your fingers crossed.