Wettable Powders/Wettable Soluble Powders, WP or WSP's as they are called
are usually good for a couple of days after mixing, before there begins a
breakdown in the container. that is not to say that it becomes unusable but
it does become less affective, and sometimes the chemical reaction in the
bottle causes the material to breakdown into other byproducts because of the
natural process of decomposition and is thus less effective.

always remember to shake well for at least 30-45 seconds before using it
after it has sat for more then a day
if you have it in a bottle more then a month just throw it out and remix
another batch as it is probably worthless

remember that orthene is naturally systemic and will travel through the
plant and is active for much longer than one might think, since the plants
are not as actively growing right now as in the spring it might take a
little longer to see the results but not to worry orthene works very well

you also might want to think about a DUNK treatment, mix up a five gallon
bucket and use packing tape to tape the top of your pots so the media does
not float out of the pot and then submerge the entire plant and leave it
there for at least five minutes as this will assure complete coverage of
roots, plant, and media this should stop all mealy problems dead. and since
orthene is systemic it will continue to control piercing/sucking bugs for a
good long time as the material moves through the green part of the plant

Jim
"Gatesjones" wrote in message
...
Hi All,

I have been trying Orthene 97 on a mealy infestation. My question is,
once I mix up a batch, how long is it effective if it is not used right
away?

Steve