On 13/01/2014 11:18, Nick Maclaren wrote:
> In article <KGOAu.1654$2j5...@fx02.am4>,
> Martin Brown <|||newspam|||@
nezumi.demon.co.uk> wrote:
>>
>>> We got no apples this year, because of catastrophic woolly aphid.
>>
>> Crumbs! How did they manage that? Last year was so good for apples that
>> the trees were in danger of fracturing branches with the sheer weight of
>> fruit. You can control but not eliminate woolly aphid on apple trees
>> with a stiff brush dipped in meths (wear eye protection).
>>
>> It is in the cracks that they lurk and keep open wounds on the tree. But
>> even on my parents where woolly aphid is completely out of control I
>> have never known them prevent an established tree from fruiting.
>
> Sorry - my error - it is rosy apple aphid. 90% of the leaf clusters
> and all of the fruit ones were infested, and the former were curled
> up beyond hope.
Oh. Nasty. I think if I had already lost the apple crop I'd have hit it
with something systemic intended for aphids on ornamental roses!
Or systemic and intended for food crops but OK to use on rosaceae.
>
>>> Now, the traditional solution is a tar oil winter wash, but the UK
>>> has banned that for domestic use. There are some organic replacements,
>>> but they don't look at all effective, and I don't want to harm the
>>> plants by using strong disinfectants (e.g. Armillatox or Jeyes'
>>> Fluid) in the absence of advice.
>>>
>>> So what would people recommend?
>>
>> Tar oil winter wash using the modern Jeyes fluid formulation.
>> (will kill anything green it touches - pretty much is a refined version
>> of tar oil but lacking some of the more carcinogenic components).
>
> Thanks, but how do you use it? I.e. what dilution and on what?
Brush or spray the bark with a 1:20 diluted emulsion and be sure to
protect anything green that might get the spray/drips on it (and your
own skin - very definitely a job for scrap clothes on a still day).
It messes up the sprayer and smells awful in the air just like the real
tar oil wash. Eye protection goggles essential however you apply it.
Obviously it would be off license use of Jeyes fluid but you basically
only want to put a very thin layer of it on the outside of the tree to
discourage any eggs overwintering there. You never get 100% kill with
anything based on contact so you need to be vigilant in spring.
Alternatively you could try the organic neem oil mixture which is
supposed to work after a fashion but I have never tried it.
I loose most of my gooseberries to American mildew because I tend to
miss the window for spraying them prophylactically against it.
--
Regards,
Martin Brown