vegetables

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Ask the industry
THERE ARE MANY TERMS IN THE
HORTICULTURAL CROP PROTECTION
MARKET THAT WE ALL USE AND
HEAR FREQUENTLY, BUT MAY
NOT COMPLETELY UNDERSTAND.
SYNGENTA TECHNICAL SERVICES
LEAD SCOTT MATHEW EXPLAINS
SOME OF THE MOST COMMON TERMS
THAT ARE USED ON A REGULAR
BASIS IN THE INDUSTRY.
Mode of action (MOA)
describes the biochemical
processes by which the
fungicide you apply controls the
disease (for example, disrupting
cell wall synthesis).
Target site is the exact location
within the disease where the
crop protection product works,
such as interfering with the
activity of a specific enzyme
within a metabolic pathway.
Protectant/contact fungicides
(see below) work on plant
surfaces where they form a
chemical barrier between the
plant and fungus. There is no
movement of the fungicide
into the plant. Protectant
fungicides must be applied
prior to infection and re-applied
to new growth if conditions
remain favourable for disease
development.
Contact activity
Fungicides that penetrate
plant tissue following the
application (and also function
as a protectant fungicide at the
site of contact) are generally
labelled as systemic fungicides.
This can cause confusion in
the market because many
understand the term ‘systemic’
to mean that the fungicide
applied to one section of the
plant will move around within
the plant to control disease in
other areas. Fungicides labelled
as systemic have very different
degrees of systemic movement.
Translaminar fungicides (see
below) move through the leaf
or plant tissue from the side in
which they are applied, to the
direct opposite side of the leaf
or plant tissue.
Translaminar activity
Xylem mobile fungicides (see
below) move in an upward/
outwards direction from where
they are applied in plants with
water through the xylem – the
water-conducting tissue of the
plant. This movement is also
known as acropetal movement.
Leaf or locally systemic activity
Xyleme mobile
Fully systemic fungicides (see
below) move both upward
through the xylem, and
downward through the phloem,
or the food conducting tissue
of the plant. This movement is
also sometimes described as
basipetal movement. Very few
fungicides and insecticides
registered in Australia are
classed as fully systemic.
Plant systemic activity
Phloem mobile
with Scott Mathew
Please ask your local reseller
or consultant how the crop
protection product you are
applying works either on the
plant surface or within the plant.
For example, is it a protectant/
contact, translaminar, xylem
mobile or a fully systemic
product?
Understanding how the crop
protection product moves
within the plant will help you to
better set up your application
equipment to maximise the
performance of the crop
protection product applied.
i
For more information or
to ask a question, please
contact your local Syngenta
Territory Manager, the
Syngenta Advice Line on
1800 067 108, visit www.
syngenta.com.au or email
Vegetables Australia: info@
ausveg.com.au. Please note
that your questions may be
published.