Kitchen Garden Forum

There's always something...

http://www.telegraph.co.uk/foodanddrink ... -crop.html

I thought blight was worst that could happen to my poor tomatoes!

Well let's all hope that they don't spread too quickly.

I found this with an image of the moth, and it also attacks aubergines, peppers, potatoes and solinacious weeds, etc

Tuta Absoluta or the South American tomato moth -

http://www.russellipm-agriculture.com/s ... =1&lang=en

maybe grow under enviromesh might protect, like we do for cabbage white
butterfly ? maybe they won't tolerate a hard winter?

Hi Chantal,
The thing that really worries me is the lack of treatments available to the amateur gardener to actually tackle what potentially is a very serious pest.
Will those who are strictly organic take the necessary action even if such a treatment is made available.
To me this is where it all falls apart and why organic and conventional gardeners cannot really ever unite.
JB.

At least there seems to be a pheramone lure ready and waiting, which must be a good thing.

See http://www.tutaabsoluta.com/

Effectiveness of chemical control is limited due to insect's nature of damage as well as its rapid capability of development of insecticide resistant strains.

So chemical controls are relatively ineffective, and arguably do more harm than good.

Sex pheromone trap is using as an early detection tool. Mass trapping and lure and Kill application of pheromone has been found to be effective to control Tuta absoluta.

But good old trapping (which should be OK for organic growers) is effective.

Not a great opportunity to roll out the old anti-organic hobby horse then.

Wondering if the pherome only lures that particular moth or if it traps other harmless pollinating moths too?

http://www.chem-tox.com/pesticides/

Having read the research above, I think pheromes are a much better option than pesticides.
Maybe interplanting and companion planting might make them less attractive
than the usual monoculture which must look like the moths birthday treat, and draw large numbers!

As I have always understood it, pheromones are many and varied and serve various purposes, especially in insects, but they are species specific. There would be little point in a sex pheromone which attracted other species.

Thank you Alan.

Hi Nature's Babe,
I hate to disappoint you but Pheromone traps were introduced in order to give horticulturalists an indication as to the best time to apply insecticides to kill off the the specific pest they needed to target and therefore on their own pheromone traps only do less than half of the job and certainly are of scant use when trying to eradicate anything.
This pest needs to be eradicated without any pussy-footing!
JB.

Johnboy wrote:Hi Nature's Babe,
I hate to disappoint you but Pheromone traps were introduced in order to give horticulturalists an indication as to the best time to apply insecticides to kill off the the specific pest they needed to target and therefore on their own pheromone traps only do less than half of the job and certainly are of scant use when trying to eradicate anything.
This pest needs to be eradicated without any pussy-footing!
JB.

Unfortunately Tuta absoluta has been shown to develop or even have resistance to many chemical controls, so eradication "without any pussy-footing" may be easier said than done.

An interesting research paper from Brazil on Tuta absoluta in Argentinna...

http://www.scielo.br/scielo.php?pid=S15 ... ci_arttext

I don't think it will be too serious a problem in a non-commercial greenhouse. It says it is introduced from on fruits or plants brought in, so if you grow your own from seed it shouldn't find your plants in the first place.

Also on a small scale you can easily look under the leaves every few days and remove any eggs you see on the underside of leaves, if the moths do spread to our gardens. They can overwinter in the soil if there isn't any vegetation for them to hide in, so I suppose growing in fresh compost would solve that problem. It also says they don't do so well in cool temperatures or in wet weather, so they shouldn't spread very far in Britain.

It did occur to me that a potential source of spreading the insect to domestic growers is the new idea of supplying grafted tomato plants, so I'm sticking to growing my own. I can grow more than enough for my family and friends without needing to pay over the odds for bought plants which may have higher yields but could be a possible source of unwanted pests if the controls aren't so effective.

Hi Tony,
I would suggest to you that the vast majority of contributors to this forum, me included, are not aware of the full extent of the pests and diseases that affect the plant family Solanaceae.
At a very young age it was ingrained into me by my peers that it was imperative that all the waste from this family of plants should be burnt and the waste should never ever be added to compost. At that stage of my life blight was only talked about but never actually experienced. I didn’t actually see a case of blight until the very late 1950’s. Even in those days those who were organic burnt their solanaceae waste as a matter of good gardening practice.
Then came the advent of modern organics when those who really didn’t know much about gardening or growing anything became experts and whatever they wrote became organic gospel. In a frenzied attempt to grow their own organically common sense practice was brushed aside. It is from these frenzied days that our present problems stem. I might add that they were egged on by a continual barrage of scare stories from an organic organization seeking recognition.
I can envisage sometime, not too far into the future, when amateur gardeners will give up growing Potatoes and Tomatoes as a total waste of time and effort. Should this actually become a reality then the blame should be very firmly laid at the door of modern organics.
I hasten to add that I was organic until the late 1970’s when I gave up because it was becoming apparent that clear cut science was being ignored and inappropriate methodology was becoming the norm.
Although organics is a very simple method of growing it is very highly science based but the practitioners and organizations appear to sneer at scientists and prefer to think that their method of growing comes from the visceral.
If the isolated outbreaks of Tuta absoluta are not eradicated then we will have to simply add another very very unwelcome pest to the list.
JB.

Hi Plumpudding,
Your quote.
It did occur to me that a potential source of spreading the insect to domestic growers is the new idea of supplying grafted tomato plants, so I'm sticking to growing my own.

May I suggest you research a little into tomato root stocks and you will soon realise how wrong your thinking is.
JB.

In what way am I wrong in thinking that if the moth is present in commercial greenhouses, and the eggs, larvae can be transported on plant material, then there is the possibility of introducing it into a domestic greenhouse by buying something raised in a commercial environment, if it is the case that the insect is difficult to see if it is inside the leaves or stem and difficult to eradicate with insecticides used at the moment?

Although one article said that their company had just completed tests on something which did appear to control the pest, so I'm sure the commercial growers will be taking all the steps they can to control or eliminate this moth. One of the suggestions as well as insecticides was to cover all the openings with insect mesh to keep it out in the first place.

My thinking is that there is less chance of the problem occuring in an ordinary greenhouse if you don't introduce things from outside. I'm not interested in plants that produce huge quantities of fruit as I get very good yields from the 40 or so varieties I save seed from. I'm not saying that the grafted plants are not a good idea, and if you want to produce more fruit from a few plants in a small greenhouse by all means try them, I was just saying I can grow more than enough for my needs without spending money on grafted plants and running the probably very small risk of introducing foreign nasties.

If I'm missing the point and they raise the plants in a completely sterile environment, or dip them in bleach or something, I'd be interested to hear about it.