David in Normandy wrote in news:4defd3c0$0
:

The Palmolive brand washing up liquid was effective against the black
fly on the broad beans, one or two are appearing again now though so
time for a respray.

How about white fly? Some of young brassica plants are looking poorly
and investigation shows some of them have white fly underneath the
leaves. Will washing up liquid be effective against them too?

David,
Last year I had a huge whitefly infestation with all of my brassicas.
I think it was because I noticed them too late and could not keep on top of
them. I took remedial action by using a car vacuum cleaner. ALL of the
brass. suffered and were not really worth harvesting, but the vac worked a
bit
This year I have used a systemic bug killer on all brass. when planted, at
2" tall.(I grew all from seed). They look good now, but after spraying
looked sick with yellow leaves. We will see what happens after the second
dose. It says on the label to use every 4-6 weeks.
I HATE using chemicals but I aren't watching my garden turning into a haven
for unwanted, disease carrying flying insects again.

If you are interested the product I have is a Bayer Garden product called
"Provado Ultimate Bug Killer Concentrate2"

BTW if you nip the tops out on the broad bean plants after some pods have
set the blackfly will be gone and also will encourage new pods.

I hope this helps, David

Baz