Provado

[Eric Williams]

Hi all, As Provado is listed as a systemic, is it best to spray/drench plants prior to seeing pests, or wait until some thing is spotted then spray. The thinking behind this is. if there are no pests around would it not be a waste to spray that early. ? Thanks

[lobman]

The trouble is pests are always around , ( unless you grow from seed in the Antartic ) so a couple of treatments a year is money well spent

[gerald]

This is true, prevention is better than cure.

[graham]

But there is one major issue with such regular treatments with the same insecticide and that is the build up of resistant insects. There are plenty of references that describe the effects - I rather like the 'pesticidestewardship.org' name - an interesting concept - however their pages are worth reading:
http://pesticidestewardship.org/resista ... tance.aspx
and the link to 'Take Steps to Avoid Insecticide Resistance'
http://pesticidestewardship.org/resista ... tance.aspx

Now I do appreciate that there are fewer insecticides available to amateurs than there have been in the past but nevertheless if you can follow the advice and really only spray when necessary and then change the class of insecticide that you use it should help you in preventing resistance and after all you really do want 'your' pests to be easily killed...

graham

[iann]

If you spray an orchard just for fun, you're encouraging resistance because you won't eradicate every insect and the survivors can be the start of resistance. If you drench your collection of cacti a couple of times then you're completely eradicating any susceptible pests, which doesn't encourage resistance. Rotating through different pesticide groups would be better but we've been banned from such sensible options. Of course if you're fairly confident that you don't have any mealies (really the only target pest for Provado in a cactus collection) and you haven't introduced any new ones then you don't have to treat. If you're fairly diligent about inspecting your plants then you could wait until you spot something again, then treat everything.

[Eric Williams]

Thanks for all useful replys,I really appreciate it. I will ring the changes re pesticides. I am fortunate in still having some of the older stuff available to me, such as Malathion,Longlast. Plus a few more. As these have been banned for safety reasons I think, I will take great care in their application. Thanks. Ps, I see the odd one or two mealy bug, but WFT is a niusance when flowers are out.

[iann]

Thanks for all useful replys,I really appreciate it. I will ring the changes re pesticides. I am fortunate in still having some of the older stuff available to me, such as Malathion,Longlast. Plus a few more. As these have been banned for safety reasons I think, I will take great care in their application. Thanks. Ps, I see the odd one or two mealy bug, but WFT is a niusance when flowers are out.

I think it is important to point out that Dimethoate, and especially Malathion, are banned for bureaucratic and business reasons rather than on safety grounds. The EU has declared that everything is dangerous unless some company wants to come along and sell it badly enough to pay a whole bunch of money to get it registered. Nobody wants to sell Malathion because it is not patent-protected, hence it has cannot be sold.

The WHO rates Malathion in a less toxic category than Thiacloprid. I don't recommend you drink either of them, although people have over a considerable period of time without harm (oh, the 1950's, what fun!). Dimethoate is considered in the same acute toxicity category as Thiacloprid, so somewhat more toxic than Malathion. In particular Dimethoate is considered more toxic by skin contact. Both are still widely used in Europe (Malathion is still sold as a head lice shampoo), just not available for retail sale as a plant protection product, in fact illegal for non-qualified persons to use or possess.

Malathion and Dimethoate are in the same mode of action group, but it is a different group to Thiacloprid. Malathion is strictly a contact insecticide while Dimethoate is also systemic. They both have a much stronger and more unpleasant odour than Thiacloprid.