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Posted by first_timer1980 (U13970469) on Thursday, 1st July 2010
Realistically how much damage can a black fly infestation do to your crops? Anyone had any experience of this?
Realistically....they can ruin your whole crop if left.
I had a tree in the front garden which for 3 years on the trot was covered in blackfly, I didn't notice them until it was too late, every leaf eventually was desimated by them. In the end I cut it down, now I've learnt they were probably being farmed by ants hence them returning to the same tree each year.
I think this is going to be a bad year for blackfly - and greenfly for that matter!
I already have colonies of blackfly on my runner beans as well as on my broad beans. In have sprayed with dilute washing-up liquid (successfully) and squidged small colonies (yuk!) but I have to be vigilant.
They are colonising the poppies, honeysuckle and roses as well. The general spray works pretty well, but I have to check daily to ensure no further infestation.
I lost a mature honeysuckle once because of aphid infestation. I am much more pro-active these days.
PHJ
I've had colonies of blackfly on my cherry blossom tree twice this year, being farmed by ants. I took off the offending leaves and smeared vasalin around the bottom of the trunk to prevent the ants getting back onto the tree but then noticed the ants were getting back on because my rasberry leaves were touching the trunk just above the vasalin.
Resourceful little critters aren't they.
They kill the plant, then you have no crop!
Realistically, if we were subsistence farmers, we'd get hungry and the blackfly very fat!!
So far our brod beans are not affected, now I've said that they will be covered by tomorrow night!
You may very well be infested within a day, Bookertoo! You look at a leaf one minute - no problems. Next time you look - the dreaded colony has established itself.
I have sowed a dwarf broad bean this year - in the vain hope that it would be less prone to blackfly. Huh!
PHJ
I might grow companion nasturtiums if black fly is a problem because they will be more attracted to them than crops. Whether the professionals would agree, I don't know.
I tried that Paull2 - all it seemed to do was give the darned blackfly more opportunities!
PHJ
You are not wrong regarding the speed at which the blackfly can get established, I'm checking at least daily, if not twice a day - I don't expect to have immune broad beans!!
I've been out there twice today - squidged several colonies in the making.
A bad year for blackfly (or a good one, depending on whether or not you're a gardener or an aphid, I guess )
PHJ
I've had blackfly on my broad beans and it's stopped them in their tracks. I've had some beans off them but not expecting a whole lot more even though the blackfly have now gone (I had loads of ladybirds and also sprayed with soapy water).
I've noticed today that there are some black flies on my cauliflowers but not sure if they're the same thing or not.
Glad it's not only me then. The black fly are terrible this year. I have been constantly checking the plants and squashing any that I find. They are even on things that have never had them before, like the tangerine dream poppies, so it is a bit of a pain.
What sort of soap should I be spraying edibles with?
, in reply to message 13.
Posted by Playingtimeaddedon (U14150224) on Sunday, 4th July 2010
When it comes to gardening, I am not organic. If I have a green/blackfly infestation, I spray with a propriatory brand of pest killer.
I follow the instructions and do not 'add a bit extra just to be sure'!
I spray at sun-down, when bees are not active, and if the pest killer says that I can eat the veg/fruit in 24 hours, I give it at least another 24 before I pick.
If soapy water were a killer, my children would never have made it to be adults.
Companion planting? I have tried many combinations that have been 'guaranteed to work' and have been left with pests on both sets of plants.
If you catch them early and the blackfly have just started colonising a few leaves nip these off.
I use washing up liquid but sparingly, in warm water with a small amount of vegtable oil, too much detergent and oil may kill the remaining leaves on the plant. I did that last year
Black/greenfly breath through their skin, the mixture suffcates them, so you only need to spray were the infestation is.
If you aren't sure about using detergent then there are products from the GC as the last poster said which will kill them.
This is only my second year on the allotment, but,as other people have said, the number of black fly this year is much worse than last. Does anyone know why this is? I live in the south and we have had a very dry summer - is that anything to do with it?
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