Sunday, June 22

Blighted

If you read Martyn's blog you will already know that we have been hit by the dreaded blight. Not us personally of course but our potatoes.
It was bound to happen I suppose given the weather conditions.

Blight is a fungal disease that affects potatoes and tomatoes. It is spread by microscopic spores that thrive in dull humid conditions. Blight is more likely to raise its ugly head during Smith periods. This is where the minimum air temperature was 10 degrees centigrade and for 11 hours there has been a relative humidity of 90%. If there is a Smith period for two consecutive days then blight spores can invade. As you can see above the first symptom is the appearance of greyish patches on the leaves. From this point the infections can spread down the stems totally destroying the top growth  before moving into any tubers that have formed.

Blight is one reason why we don't grow maincrop potatoes and stopped trying to grow tomatoes outdoors. Usually if blight is going to strike on our plot it is in July and August which means early varieties of potato have managed to produce a crop before being struck down, however this year unusually blight has arrived on the scene early.

The potatoes to be affected so far are the ones that we planted earliest. Below on the left are two rows (Rocket and Casablanca) grown through weed control fabric and 'earthed up' with straw. On the right are five rows (Rocket, Casablanca, Nicola and two rows of Winston) which have been grown and earthed up as usual. These two beds are about 60cm (2 feet) apart.
The potatoes grown through the fabric have so far had fewer affected leaves but this could be a coincidence or because there are fewer rows growing close together giving better air circulation rather than because of the fabric.

To try and cut down the spread of the disease I have removed as much of the affected plants material as I can. In the case of the potatoes under weed control fabric (above photos below) this was just affected leaves whereas in the case of the potatoes in the other bed some tops had to be cut down completely.
I'm also hoping the fact that we have had a couple of dry days may also have helped and that even if we can't save these potatoes that those grown elsewhere on the plot will be unaffected. The greenhouse has been kept firmly closed to try and protect the tomatoes. The removed plant material had been bagged to be disposed of away from the plot

As some of the Winston potatoes had no foliage left we decided to dig up a plant to see if it had produced a crop. 

So was there anything to harvest?


It hadn't produced a huge crop but left us with some hope of some sort of harvest.



31 comments:

  1. Oh no ! I planted our Tomatoes in the garden yesterday. Maybe I should have left them in the Greenhouse. This is not good news. Thanks for the warning Sue

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    1. I don't think the risk is as high in a garden as on an allotment, Marion. The problem is so many potential victims in close proximity.

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  2. Let's hope the dry weather is here for a while and that it slows down its spread. This shows how it pays to be vigilant, it can't be easy keeping an eye on everything when your plot's as big as yours is so you did well to spot it.

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    1. We usually have a wander round and look everything over each time we arrive on the plot. Jo

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  3. How frustrating for you. Hope you get enough of a harvest to make all the work worth while.

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  4. Gardening is a constant battle against the elements and various pests and pestilences! I'm writing today about the contaminated manure situation...

    I hope you manage to rescue a decent proportion of your crop.

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    1. Isn't it just, Mark. With the odds stacked so much against us - it's a wonder that we manage to successfully grow anything

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  5. I hope the rest of your plants stay disease free long enough to harvest. It is a really frustrating disease as it spreads so quickly.

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    1. It is a frustrating disease, Daphne which we seem to get far too often. Last year the dry conditions meant we avoided it but obviously the spores survived just watring for their chance to pounce.

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  6. Sorry to hear that. I hope the disease does not progress.

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    1. It's still getter worse on the bed with the five rows, Alain.

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  7. Oh Sue that is such bad news for you, I briefly thought about blight the last week. I hope you get a usable harvest.

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    1. I thought about it too, Jo when the weather was so muggy - ideal for blight

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  8. This year I'm testing ecological spray on my tomatoes, I'm using a solution of calcium acetate and a solution of thymol. So far, so good, I hope it will protect my plants. Two years ago blight destroyed my tomatoes, but then I didn't even know what hit us, well I didn't even know that we were hit, I thought tomatoes were just sick or had deficiencies, I didn't know about blight.

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    1. What's more, these two sprays can be easily made at home.

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    2. Look forward to hearing how your spray performs Dewberry

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  9. AnonymousJune 22, 2014

    I feel for you Sue, I have had it in years past. When I was involved in commercial growing we used to get a warning from NAAS (DEFRA now) who tracked its progress across the country. When it was received it was all systems go with the Copper Sulphate spray!

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    1. We usually subscribe to Blightwatch, Rick but then their is little available to amateur gardens as a way of protecting crops from blight.

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  10. Shame about the blight, hope it isn't too bad, and hope it doesn't spread.

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    1. One bed is looking fairly sorry for itself Kelli but I am continuing to remove any affected plant material just to try to contain things.

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  11. Your blight has come early - what a shame - hope you manage to harvest before the tubers become affected.

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    1. The earliest we have ever known it, Elaine :(

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  12. How blommin' annoying after all your hard work! I've never had blight....fingers crossed. I hope your swift action and some sunshine has nipped it in the bud!xxx

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    1. Just hope it stays confined to the beds it has attacked, Snowbird as at least they have been planted up the longest so may have a crop of sorts

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  13. I am so sorry Sue, I have experienced the effects of blight before on tomatoes and it is the most devastating loss I have ever experienced in the garden. That was before I started growing potatoes. I hope you caught it in time and your tubers are not affected.

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  14. I have an allotment in Pontefract and have just discovered potatoe blight. I can't believe how early this blight attack is! Half my plot is dedicated to potatoes and tomatoes so this could be a very bad year.

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    1. It's incredibly early this year ,Craig. We started growing beg some 20+ years ago and never known it be this early. We were spoiled last year and nearly tempted to try outdoor tomatoes again.

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  15. Goodness, I am so behind in blog reading ... only just discovered this.

    And there I was thinking I'd been unlucky getting hit at the beginning of July and you were caught nearly two weeks ago.

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    1. So far at least it seems not to be spreading too far, Jayne - why did I say that?

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