LAND CRESS - Barbarea Vulgaris - Kills Grubs Fast ?? Safe??

BuiDoi

The botanist said... it attracts the badies, better than anything..
When the grubs start to eat, they die real dead..

Dr. Google suggests that Barbarea Vulgaris is actually "Winter Cress"... but
the common 'tater said his gran used Land Cress and she had NO grubs on cabbages etc.

So is it Barbarea Vulgaris
and is it Winter Cress or LAND Cress

and is there any issue with AP, fish etc. etc.
..
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Bodgy

Gardening Australia just mentioned this in an episode.
It was definitely Land Cress (Barbarea Vulgaris) that was mentioned by a PhD student as a biological control.
I'm off to google it now, thanks for bringing it to my attention or I might have missed the reference on the tv.

Matthew

I have Land Cress planted here in a growbed about to flower ,and it has a few holes in it, been there for a couple of years .
I also have cauliflower 3 beds down riddled with diamond back moths.... :dontknow:

Don't go thinkin' it's a cure all, life is not that simple :support:

Ryan seems to have great success with sacrificial crops....to my mind you would just be breeding up numbers of pest :dontknow:

coachchris

I was thinking the same thing with the sacrificial crops. What happens after they eat all the sacrificial crops and are still hungry? Do you remove & bag up? keep more sacrificials going? That whole theory is foreign to me. In landscaping, if you told a customer, the plants that were all chewed up were supposed to be there, you would be unemployed.

BuiDoi

Indeed, that is where we heard the comments..
The problem is the vast opinion on what CRESS they are talking about...
I contacted the author and he confirmed the details and where to buy the correct plant.. all ordered... very cheap..
Again the claim is that this plant actually KILLS the grubs.. and if that is true it has to be good as a sacrificial...
Cross fingers..

It does seem to be both safe for AP and for consumption...
One article had suggested that it poisoned the area of the root zone... but I am thinking that was not the same CRESS...

thanks guys..
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Snags

I just ordered some seeds.
It does attract them and then kills them.

Quote:

Most Barbarea vulgaris genotypes are naturally resistant to some insect species that are otherwise specialized on the crucifer family.
In the case of diamondback moth (Plutella xylostella) and the flea beetle Phyllotreta nemorum, the resistance is caused by saponins.
Glucosinolates such as glucobarbarin and glucobrassicin are used as a cue for egg-laying by female cabbage white butterflies such as Pieris rapae.
Indeed, the larvae of this butterfly thrive well on this plant.
Diamond back moth females are also stimulated by these chemicals, but the larvae die due to the content of saponins which are apparently not sensed by the moths.
This phenomenon has been tested for biological insect control: B. vulgaris plants are placed in a field and attract much of the diamondback moth egg load.
As the larvae die shortly after hatching, this kind of insect control has been named "dead-end trap cropping"

http://en.wikipedia.org/wiki/Barbarea_vulgaris
So it doesnt kill cabbage moths just attracts them but does kill the diamond back.
The difference in caterpillars is a few big ones for cabbage moth or millions of little ones for diamond back.
The little ones decimate everything the big ones are a problem when they eat the heart out of a plant but generally a few big holes is liveable.

mattyoga

Where did you get your landcress from Matthew? Wanted to try some.

Its important to remember that killing all the 'bad guys' will mean no food for the 'good guys' and hence no 'good guys', which will then result in the potential for lots of 'bad guys'

BuiDoi

..
[url]theseedcollection.com.au[/url]

Quote:

Its important to remember that killing all the 'bad guys' will mean no food for the 'good guys' and hence no 'good guys', which will then result in the potential for lots of 'bad guys'

not sure that killing GRUBS will do anything detrimental to the goodies

..
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mattyoga

Thanks for the link -

The parasitoids feed on the grubs (eg cabbage white) so taking them all away will effect the population, though there does become a point where some control is required or else the whole crop is lost - though if things are that bad I think exclusion is a better approach - unless you want to spray Dipel routinely.

http://www.backyardaquaponics.com/cabba ... butterfly/

Matthew

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Water cress flowering. Holy radish leaves behind it. Land Cress in the background

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Land Cress about to flower.That will make it easier to I.D
Holy radish right next to it. Pulled the cauliflowers fed to the chooks, riddled with D.B.M

mattyoga wrote:

Where did you get your landcress from Matthew? Wanted to try some. '

The Big B of course...when the big B comes to town all the little nurseries packed up. In our "B" there is a section with 4" (sorry Stuart) pots with herbs, heirloom stuff and aquatic bits and bobs next to the usual punnets. I'm sure they are laid out much the same...
Fairly spicy, like water cress X wild rocket on 'roids

Matthew

Snags wrote:

Indeed, the larvae of this butterfly thrive well on this plant.

Umm...yep

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