On 18/07/08 14:45, mw80 wrote:
Ed;804521 Wrote:
On 17/07/08 14:55, mw80 wrote:-
Hi

I have noticed yellowy patches on many of the leaves of my
brassiccas.
This seems to have especially affected the Greyhound cabbages and my
Swede. Having googled the problem i think it might be the 'Mealy
Cabbage Aphid'.

I am quite dissapointed as spent quite a lot of money on Enviromesh
in
an attempt to stop this sort of thing from happening but these things
are sent to try us!

Has anyone experienced this before and if so do you know of any
remedies that might prevent me from losing everything as i am new to
growing any veg!

Thank you
-

Hiya,

I'm in the exact same position as you. I'm a new vegetable grower and

only got my allotment last March.

But, because there was no fencing around my plot, I bought Enviromesh
to
cover my brassicas to prevent attack from rabbits , birds and
butterflies. And in that respect I am very well pleased. The product
does work and my brassicas look terrific with little damage compared
with those of my neighbours.

And yet , I have also noticed, in recent weeks, some yellowing of some

of the leaves, especially the sprouts. However, I don't know what the

cause of this is or how detrimental this is to the plants.

Have you looked on the underside of the leaves of your plants. Do you
see the aphids?

I will certainly take a look myself tomorrow and see if I can spot
anything and let you know.

Maybe just a squirt of derris (or whatever insecticide you like) is all

that is necessary.

Ed

I am pretty sure they are the Mealy Cabbage Aphid. I first noticed them
on the sprouts but squashed them all! They seem to nest in folded parts
of the outer leaves. I have now noticed them on the Calabrese, Swede
(ravaged) and Greyhound Cabbage.

I have pulled 2 cabbage out completely as they were badly affected and
i was worried that they might spread to the other plants and they would
never have been very edible

The aphids seem to suck all the colour out of the leaf turning it
yellow and dry

I am trying to be as organic as possible and i don't use insecticides
unless it's a last resort.......this might be one of those occasions!




You said you were using Enviromesh? Perhaps the aphids got in whilst
you were planting out or when you removed the mesh to do some weeding?

Now, regarding Enviromesh, tell me this... Is there enough slack in
your mesh cover to allow the calabrese and sprouts to grow to full
height? In my case, there is not, so I will have to construct some kind
of low cage with netting to keep the butterflies and birds off the
crops. But that will let the aphids in, I guess. What about your situation?

Ed