Allotment Gardening Advice Help Chat
Growing => Growing in Greenhouses & Polytunnels => Topic started by: buckwheatpie on July 08, 2012, 13:36
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Hi,
Our tomatoes have various problems this year, but there's one which really stands out as very bizarre - the top of the plant has kind of twisted and narrowed, and stopped growing upwards (though the rest of the plant appears ok). It's very hard to deescribe , so I've (hopefully) attached a photo.
The background info: They are all grown in polytunnel, and we open the sides when it gets too hot to work comfortably in there with a jumper on, and shut them in the evening. The soil had composted cow muck added in early May and the plants were planted out in late May. It is mulched with a thick layer of straw (from a conventional farm). They are watered approx. twice a week with drip hose which is laid beneath the mulch. However in places the soil is often very wet as the rainwater gathers around the edge.
Anyone got any thoughts?
Cheers!
Dom in N Yorkshire
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As it is only the one it would not be contaminated horse manure. I would just cut off the top back to the last fruit truss and let any side shoot grow on for a new lead branch.
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Thanks for your reply LilacSandy, unfortunately it's not the only one - i'd say around 15% of the total crop of about 240 plants are showing this wierd twist.
We've used the same muck on loads of other crops without a problem so we don't think it's that, however the straw is definitely suspect - it came from a large industrial farm where all they ever do is spray, spray, spray, so we suspect perhaps haulm shortening chemicals in the wheatstraw are the cause - would be good to hear if anyone else has had such a distinct sympton.
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Which other crops have you used the manure on? The herbicide aminopyralid affects different plants to a differing extent.
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Pretty much all of them! Lettuce, kohlrabi, beetroot, brassica leaf mixes, radishes, spinach, peas, broad beans, chard, courgettes and garlic to name but a few... plus with smaller doses carrots, parsnips, potatoes, all the brassicas, leeks, squashes and sweetcorn...
Admittedly this year has been an absolute disaster for the obvious (sunlight, slugs) reasons, but i haven't yet observed in any of our other crops any of the leaf curling that is apparently typical of aminopyralid toxicity - the only thing like it is in these tomatoes... and the only thing the tomatoes have that none of the other crops have is a straw mulch... (oh and very, very wet feet!)...
however, thank you very much for drawing attention to the possibility - there is certainly a resemblance in our plants to the kind of gesture shown in pictures like this: http://www.thegardenersalmanac.co.uk/Data/Aminopyralid/tomatoes.jpg.
I've been trying to find more evidence that it could be the straw shortener Chlormequat in the straw, since another local farmer told us he had a problem using manure from cows who had been partially fed on chlormequat-contaminated straw, the chlormequat persisted in the cow manure, which was then applied to his polytunnels leading to tomato problems... in any case i'm starting to realise the importance of only using crop residues and manure from known, trusted, organic sources!