Agriculture Reference
In-Depth Information
In late winter but at least 30 days before anticipated bud swell, apply a
second Bordeaux spray or a spray of lime sulfur. Follow the directions
on the label for the amount of lime sulfur to apply. Just as the buds are
swellinginspring,uptothetimeafewgreenshoottipsarevisible,apply
a spray of dormant crop oil. Again, follow the directions on the label for
application rates. The oil smothers overwintering adult pests and egg
masses.
Plant-Derived Oils
Jojoba oil, rosemary oil, and other plant-derived oils are sometimes touted as
organic fungicides, but they have yet to establish themselves as being valu-
able for crop production. Few, if any, commercial products that contain these
materials are approved for organic use.
Cinnamaldehyde
Derived from the bark of trees in the genus
Cinnamomum
, cinnamaldehyde
has proven useful as a fungicide in organic crop production. Its primary use
is as an application to root systems, and its value in organic orchard produc-
tion is questionable at this time.
Bicarbonates
Bicarbonates, both potassium and sodium, have shown some effectiveness in
controlling certain plant diseases, most particularly powdery mildew. Com-
mercial, organically acceptable products are available.
