Topic: Catastrophic Potato Problem

[ceres]

Hi garjan
It would be great to get your agriculture department's take on this.  Certainly don't want to falsely accuse our Dutch friends and start an international incident!  Just thinking out loud and wondering about commercial spraying in Kent, much closer to home and from the right direction.

Occasionally there is a mention on weather forecasts here that dust is being deposited in this area from North Africa and you can indeed see it on cars parked outside.  So I suppose if heavy dust particles can come all that way who knows what else comes from near and far?

[Melbourne12]

This is a very interesting thread.  One thing that I do know is that hormonal weedkillers don’t harm humans, so your crops will be safe to eat.  Their action is confined to plant hormones.

The rumours that such herbicides are harmful seem to have originated in the military use of defoliants, which were contaminated with dioxins.  It was the dioxins that did the damage.

I’d also thought that these weedkillers decayed very quickly in soil.  Most do, but apparently not all.  Several can last for months, and one, Clopyralid, is VERY persistent.  This is informative: http://cahenews.wsu.edu/clopyralid.htm

I’d be very surprised if the problems reported on this thread turned out to be airborne, though.  Looking up the profiles, our allotment must be within a mile of Trevor_D’s.  We suffered no such problems with potatoes, tomatoes, peas or beans last year.  And in spite of the periods of easterly wind that theoretically could have brought contamination from the Netherlands or northern France, we’ve seen no problems this year either.  Indeed our peas and broad beans are looking particularly healthy!

[innocenti]

Several fellow plot holders here in Norwich are experiencing a similar problem, we also suspect it is manure that is to blame. So far only plots that used manure from the same source are affected.
 :-\

[beanie3]

Hi innocenti - can i ask where/whom you got your manure from - i am in the Norwich area.....

This is blooming awful - everyones hard work down the drain........

[ceres]

Thanks Melbourne, more pieces of the jigsaw.  I've spent some time googling tonight and found all the stuff on dioxins, Agent Orange, the Seveso incident.  Scary stuff but thankfully far removed from modern hormone weedkillers.  It's good to know that they aren't harmful to crops and we can eat the produce safely, assuming we can produce any that is!  That's one of our burning questions answered.

It now appears our damage is only to those plots that had manure and from googling it seems that contamination of of manure in this way is not that uncommon.  The fields that produce the straw that goes on the stable floor are sprayed with this stuff to take out broad-leaved weeds.  It's just a bit concerning that the straw is then harvested, stored, used, partially composted yet the weedkiller is still so active.  I've found that there are two main types of weedkiller used in the UK but haven't yet discovered how long each remains in the soil.  That's our other burning question, IF we can find out which weedkiller we're dealing with.

I haven't heard back from DEFRA yet.

Suzanne, did a ph test today, still a perfect 7!  Thanks, it was worth checking though, the manure could have been contaminated with who knows what.

Amazin, I took the nematode paper today and compared the trichodorus example, but we don't appear to have the thickening of the roots which actually look under-developed.  Good call though, thanks for remembering and passing it on.

innocenti, I'm really sorry to hear you've got it too.  I wouldn't wish this on anyone.

beanie, fingers crossed your manure comes from soewhere else.  Keep a close eye on your potatoes and tomatoes.

I'm taking Trevor's advice and going out tomorrow to buy a pressure sprayer and get going with the bordeaux mix and my worm leachate.


 

[saddad]

Hi Innocenti... welcome to the site, if you have posted elsewhere I've missed it  :-[

[Melbourne12]

...  I've found that there are two main types of weedkiller used in the UK but haven't yet discovered how long each remains in the soil.  That's our other burning question, IF we can find out which weedkiller we're dealing with.

....

Do you know which ones they are? The trade names will do.  Then we can see if we can find the data sheets for persistence.

[ceres]

Hi melbourne
The 2 main ones seem to be:

2,4-D (2,4-dichlorophenoxy acetic acid)
MCPA (2-methyl-4-chlorophenoxyacetic acid)

I've also found references to mecoprop, dichlorprop, triclopyr and dicamba.
 

[Garjan]

Hi all

My OH works for the department of agriculture and he said the following after reading your posts:
1. There is spraying of pesticides by plane only in the Flevopolder, an area in the centre of the Netherlands. There are no complaints of airborne contamination in other parts of the country.
2. There is no spraying of fertiliser. All fertiliser is injected in the soil.
3. They know the British media mentioned a strange smell coming from the Netherlands. As it was just a rumour, the department will not react. It is impossible to make an official statement every time a rumour is spread. Complaints about possible damage to health, food quality or other dangerous things have a higher priority.
4. If the smell did indeed originated in the Netherland, it was probably coming from (petrochemical) industries near Rotterdam. That sounds much more dangerous then it is: the nose can smell gasoline before any instrument can measure it. I dare say that the smell alone does not indicate any level of risk to people or other living beings. If there had been a health hazard, the alarm systems in the Rotterdam area would have warned us in time for evacuation.

So, this is not the offical take, but it makes thing a bit more clear.

The use of weedkillers that still work after being eaten, digested and composted is something that worries me very much.
On another level: how come Brussels prohibits the use of organic and homemade weedkillers and pesticides (Rhubarb), but allows these longterm working ones? Probably a classic: follow the money!

Good luck with the treatment and saving of your crops, ceres.

Garjan

[djbrenton]

2,4D persists for between 20 and 200 days. Of course there's no data on the degradation of dioxins through digestion.

[ceres]

Thanks garjan, that's interesting.  Thanks for checking.  If it had been airborne, you would have expected surrounding areas in the Netherlands to also have been affected first.  I used to work in the oil industry and know how smelly petrochemical plants can be - comfrey tea doesn't come close!  I'm with you on the EC rules though.  It's mad.  I was reading some stuff about soft soap spray for aphids last night and an article by Bob Flowerdew said it's breaking the law to make your own mixture the way people used to using household products (Lux flakes, Stergene etc.).  Yet here's a weedkiller that must have been sprayed months and months ago and is still killing plants.  The world has gone crazy or maybe just the EC.

djbrenton, thanks for that.  If it's 2,4-D it's certainly more than 20 days now.  I got my manure last December, some people affected were even earlier than that.  The manure wasn't fresh at that point, so it had been stored for some weeks.  Would the straw that was used in the stables have been last year's harvest in which case the weekiller would have been applied some time last summer?  Which seems to be approaching more than 200 days.  We really need to speak to the farmer who, as of yesterday, hadn't replied to our messages.

[Melbourne12]

2,4-D

The half life in soil is <7 days http://extoxnet.orst.edu/pips/24-D.htm

It's actually approved for use on potatoes in Canada!

MCPA

This is a bit more persistent, but not dramatically so. http://extoxnet.orst.edu/pips/MCPA.htm suggests a half life of up to one month.

But it's interesting that MCPA is said to have "little affinity for soil", and its persistence is said to increase sharply in the presence of organic matter.  So it's possible (I'm guessing) that straw containing MCPA residues mixed with manure might keep the MCPA locked in for considerable periods.

Mecoprop

http://pmep.cce.cornell.edu/profiles/extoxnet/haloxyfop-methylparathion/mecoprop-ext.html

Low persistence

Dicamba

This is a bit scary- suggests a persistence of a year and a half in some conditions! http://pmep.cce.cornell.edu/profiles/extoxnet/carbaryl-dicrotophos/dicamba-ext.html

http://extoxnet.orst.edu/pips/dicamba.htm says "moderately persistent"

Dichlorprop is the same as 2,4-D

Triclopyr

http://extoxnet.orst.edu/pips/triclopy.htm

Moderately persistent, so could be a candidate.  Also apparently used in formulations with the dreaded Clopyralid which DOES contaminate compost.  But it isn't clear to me whether Clopyralid is still allowed in the UK.

[Sinbad7]

This is a really interesting thread although I am really sorry for all those affected but would it then be safe to assume that this is only from straw based manure?

There has always been a discussion on which manure is best, wood chips versus straw based.  I ask as we have wood chipped base manure delivered to our site from The Royal Gardens but sometimes in the delivery there is straw which is from the Queen's own horses not often do we get this and there is never that much in the whole delivery, so does anyone know if the wood chips now used widely in stables is treated with any harmful chemicals?

Maybe this would be worth looking into.

Sinbad

[Robert_Brenchley]

Does Royal Poo smell any sweeter or boost your plants better?

[Sinbad7]

LOL, I don't think sweeter but it sure makes the plants grow ;D

[Rhubarb Thrasher]

with all these problems with the provenance of your manure, I think you should only accept Royal Poo if it's been personally passed by the Queen

[Sinbad7]

 ;D ;D ;D

[ceres]

Wow, thanks melbourne.  that's great info for when we find out what was used.

Re Clopyralid, I found this:

http://www.theyworkforyou.com/wrans/?id=2007-06-11b.227.0&s=section%3Awrans+speaker%3A13301#g227.1

Written answers
Monday, 11 June 2007
House of Lords
Chemicals: Gardening

Lord Lucas (Conservative) | Hansard source

asked Her Majesty's Government:

Which formulations that include clopyralid are licensed for (a) garden use and (b) for use by contractors on municipal or institutional grasslands; and how they intend to alleviate any problems this chemical might cause for the composting of green waste by local authorities.

Lord Rooker (Minister of State (Sustainable Farming and Food), Department for Environment, Food and Rural Affairs; Labour) | Hansard source

There are six pesticide products containing clopyralid licensed for garden use:

Verdone extra (M13113);Verdone extra (M10635);Verdone extra ready-to-use (M11758);Verdone extra spot weeder (M10834);Vitax lawnclear 2 (M13508); Vitax lawnclear 2 ready-to-use (M13509); and

five pesticide products licensed for institutional grasslands:

Blaster (M10571);Blaster (M13267); Esteem (M12555);Greenor (Ml 0909); and

Spearhead (M09941).

Because compost contaminated with clopyralid may harm some ornamental and vegetable crops, the labels of pesticide products containing it have a warning to avoid using any plant materials treated with the products for composting or mulching. Therefore, grass treated with clopyralid should not be composted or sent for composting.

[ceres]

Sinbad, while I've been searching around for info on clopyralid I've found recent forestry research papers on the spraying of woodlands with clopyralid.  I imagine commercial woodlands are managed in much the same way as fields so it might be worth checking with your source whether or not there is any spraying.

[ceres]

 ;D Robert and RT!

The irony is our allotments are the Royal Paddocks attached to Hampton Court Palace, we used to pay our rent to the Master of the Horse.