physan, water quality

Wed, 31 May 1995 11:15:00 -0700 (PDT)

>John wrote:

>Which genera/species have you used physan on? I've been thinking
>of using it to combat some fungus growing in a bowl of Utricularia
>gibba ...

John, since I am relatively new to CP's, I've only used it on VFT's, Drosera
capensis and my Nepenthes alata, so I couldn't comment on other genera. A
small dilute amount in the water may help with your utricularias, though it
seems that controlling the water level might be a better way to reduce
fungal growth. The following info. from Mark Crawford was posted on the
orchid list and may be useful:

Physan and RD/20 are just 2 products in a class of products known as
quatenary ammonium chlorides. Greenshield from Whitmire is identical to
Physan and may be available to those of you in California and is sold by
Hummert in St. Louis. Greenshield is LABELED for orchids!! These products
have been around for decades and are similar to disinfectants used in
hospitals. Compared to standard fungicides and bactericides they are
inferior products, however for orchids they work well because they keep
the plants clean. If you have a serious disease problem other products
like Kocide, thiophanate-methyl (benlate substitute),dithane and subdue are
more effective. Has anyone tried Banner fungicide? It works great on leaf
spots. It is registered on trees, shrubs, bedding plants but not orchids."

Are these registered for carnivorous plants? One important function of
physan is keeeping the plants 'clean' , thereby reducing the likelihood of
infection by fungal spores and bacteria. Physan may not help an already
infected plant but it could be a useful component of a prophylactic program.

Thanks for all the hints on feeding Nepenthes. The issue of water quality
for pitchers was raised. What are the maximum levels of dissolved solids,
and highest electrical conductivity that is suitable for tropical (and
other?) pitchers? Has anyone done a water quality analysis? I doubt that
most hobbyists use RO water, unless their water quality is pretty bad to
begin with..