Re: Peronospora in Salvia splendens

["Robert R. Dockery" <grnthumb@sisko.se.wp.cc.nc.us>]

Hi,
Regarding your problem with Downy Mildew as it is known by its common name
in the USA...
...from your brief note announcing the problem, I can only assume that you
are growing in a greenhouse situation.  Please correct if wrong.
Downy Mildew (Peronospora antirhinum) attacks the leaves primarily on the
UNDERSIDE of the leaves.  So be sure your spray program is coating the
underside of all foliage.  Also, sulfur is a natural fungicide and can be
mixed with water to make a slurry (a water + sulfur) mix that can still
move through a sprayer.
Also, try to insure your air circulation in the greenhouse (again assuming
this is the situation) is good.  Addition of simple box, window fans to
move the air--particularly at night--helps you to keep control.  Insure
that your plants are not too tight (its tough growing bedding plants
without crowding, I know).
Try watering early in the morning so that any excess moisture can
evaporate.  
During rainy weather, try to keep the foliage as dry as possible.

These tactics are what I would try, hope you have success finding a
working combination for your situation.

-Robert R. Dockery
Horticulture Technology
Western Piedmont Community College
Morganton, NC
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On Tue, 1 Sep 1998, Hans Hermann Hesse wrote:

> Hello,
> I am  growing bedding plants and this winter we had  a lot of rain and it
> is very difficult to maintain  humidity  low .  In my Salvia splendens 
> crop I get  trouble with Peronospora and  ther is  nothing what helps to
> spray. Somebody  can help me with a hint ?
> Any further information  please mail to  Hans Hermann Hesse
> ursula@visao.com.br
>