Garden & Greenhouse August 2018 Issue | Page 16

garlic extract
plant extracts
Plant Extracts in Pesticides and Fungicides
Most plants have their own built-in mechanisms
to protect themselves from various pathogens or
animals. As scientists gain understanding about the
specifi c compounds created by plants for defense, potential
plant-based pesticides and fungicides are discovered.
Particular compounds in plants, due to their
natural antimicrobial and insecticidal properties, are
now being incorporated into natural pesticides and
fungicides. These plant extracts can be directly used
or the specifi c substances responsible for the antimicrobial
or insecticidal properties can be isolated and
incorporated into pesticides and fungicides.
Aloe Vera Extract
A relatively new extract to exhibit potent antifungal
properties is an extract obtained from aloe
vera. Aloe vera extracts have been found to have
anti-fungal activity against some of the most common
post-harvest pathogens, including penicillium expansum
(blue mold) and botrytis cinerea (bud rot). Aloe
vera extract is also used as a soil amendment to control
moisture. In fact, aloe vera added to a soil which
has been inoculated with benefi cial microorganisms
will protect the microorganisms from extreme conditions.
Prepackaged soils that do not contain aloe
vera extract will not be able to protect the benefi cial
microbes when the soil is stored in hot or cold conditions.
Garlic Extract
Garlic extracts are becoming more and more
popular in organic horticulture. This powerful plant
has a natural fungicidal property and the ability to
destroy bugs on contact. As an insecticide, garlic extracts
work most effectively as a pest insect deterrent.
Because pest insects are adversely affected by garlic,
they will immediately pack up and fi nd another place
to live. Many pesticide companies are combining garlic
extracts with other organic active ingredients to
maximize effectiveness.
Clove Oil
Similar to garlic extracts, clove oil is becoming a
popular additive in many organic pesticides and fungicides.
Eugenol is a compound extracted from clove
which has displayed powerful antimicrobial properties.
Insecticidal products made with clove oil are excellent
contact killers.
Rosemary Extracts
Special compounds found in rosemary extracts
block the octopamine receptors of many pest insect
varieties. Pest insects sprayed with a rosemary extract
solution will experience paralysis and eventually
death. Because octopamine receptors are specifi c
to insects, rosemary-based insecticides show great
promise as a safe alternative to chemical insecticides