Re: CULT: Borer, spraying, and the sun



>And I would say from experience that if you use liquid dishsoap as a sticker
>and spray a very warm day or in very strong sun you risk burning your irises
>badly and while they will recover, they will be sad plants and sad looking
>plants for a good while. This also holds for spraying them with insecticidal
>soaps.
>
>Anyone know if pyrethins have any effect against larvae of anything? Or the
>soaps, for that matter?

I've had bad results with insecticidal soaps burning plants both in the
garden and in the greenhouse. I don't use them anymore because they seem
also to be relatively ineffectual against such things as whitefly and
mealybugs, which is what I wanted them to kill.

Pyrethrins natural and synthetic are contact poisons, as are insecticidal
soaps.  Pyrethrins have a very short (few days at most) life in the
environment, so are relatively safe.  I don't know of any adverse effects
on humans.  Raid relies mostly on pyrethrins.  I've found their garden
formulation to be good for aphids and whitefly.

Bill Shear
Department of Biology
Hampden-Sydney College
Hampden-Sydney VA 23943
(804)223-6172
FAX (804)223-6374
email<bills@hsc.edu>




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