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Old 04-10-2009, 04:33 PM posted to uk.rec.gardening
Sacha[_4_] Sacha[_4_] is offline
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Default biological controls

On 2009-10-04 12:42:24 +0100, K said:

Sacha writes
On 2009-10-02 16:07:15 +0100, K said:

Sacha writes
Kay, I asked Ray about this and he'd had identical experiences many
years ago when using a compost which contained something that killed
off vine weevil but unfortunately, it also killed off the predators. He
can't remember the name atm but I'll post it if and when he does! For
quite a long time the makers denied this but in the end, so many people
remarked upon it that they had to admit it should not be used where
biological control predators were being used. So he wonders if you've
been using something similar.
I haven't changed my compost between .3 years ago when I got good
control and the last three years. I use New Horizon.


And it does have anything added to it to control vine weevil -
something Green, IIRC. It's one of those names that just will not stay
in my head!

No mention in the data sheet of added pest control. Are you sure that
it does? If so, I'll have to ask the manufacturer about it. I'm
inclined to think not, else I wouldn't have had success with the
predator in better years.


No, I made a typo there. I meant to say "does it", not "it does". Sorry!



However, the pesticides get onto e.g. plastic pots and that holds a
residue for rather a long time. I have at the back of my mind some
experiment or other that Ray carried out - or found out about - I'll
try to remember to ask him about it.


Again, that's something I'd expect to happen every year, but it is
worth investigating.


I'll get him onto it when he comes in from the RAIN!


In sunny Leeds - perish the thought. ;-) i.e. Probably!
I still have a few predators - the odd cocoon type thing here and
there, so slow breeding seems the most likely.


Of course, once the predators have eaten all the nasties, they, too,
will die off so you may have to start again next year.


That's not a problem that I've had in the last three years ;-)


I almost wish you had. ;-)
--
Sacha
www.hillhousenursery.com
Shrubs & perennials. Tender & exotics.
South Devon