For healthy potatoes - Bayer CropScience

versely, its weaknesses. For diseases such
as snow mould, the duration of protection
provided by a product can sometimes be a
critical factor.
Beyond controlling pathogen fungi,
seed-treatment has traditionally served to
prevent infestation by pests. Examples
include bird repellency, and the control of
wheat bulb fly. One important area is the
control of aphid species, especially those
that act as vectors of barley yellow dwarf
virus.
The quality of the
formulation underlies the
success of seed-treatment
The quality of a seed-treatment product
is not simply determined by its spectrumof-action.
Other factors are also involved
in determining, for example, the compatibility
of the various components of the
treatment with the crop plant. The formulation
– i.e. the mixture comprising the
product – significantly influences crop
compatibility: water-based products are
Seed treatment should
therefore not only be judged on
the basis of cost. It should also
be considered as an insurance
policy, and this is reflected
in the higher price paid
for treated seed.
generally more favourable here than solvent-based
formulations. However, the
most important determinants of a formulation’s
crop compatibility are the active substances
it contains. Formerly, the triazoles
were often implicated as a source of problems:
they were included in the formulation
to increase the spectrum-of-action; but
the high doses used were often enough to
jeopardize crop compatibility. Nowadays,
the combination of the different compounds
used must be considered together
with the type of formulation. Here it is also
the case that differences in compatibility
among seed-treatment products only tend
to become obvious when the plant is
stressed. Delayed emergence can usually
also be attributable to external factors such
as temperature, soil conditions and other
factors.
There has been a general trend towards
developing new products as water-based
formulations, although not so much with
crop compatibility in mind, but rather with
the intention of improving
the protection of the
user and non-target
organisms in the environment.
These factors (and of
course, the cost of a
product) are important,
but technical quality is
becoming an increasingly
significant determinant
of the competitiveness
of individual
seed-treatment products.
Here, the physico-chemical properties of
the formulation are also a basis for differentiating
between products: they have a
significant influence on how easy it is to
work with the product. Together with the
equipment used, they determine the quality
of the treated seed lots, and are among the
most important criteria for the selection of
a particular product by the operators of a
seed-dressing unit. If a product constitutes
a hazard to operators, or if the poor workability
of a formulation causes technical
problems during the peak work times in
autumn and spring, then it has little chance
of remaining on the market, even if it
shows good biological efficacy and is
cheap. Working methods within seedpreparation
units often mean that universal
treatments are preferred, because they
allow a switch between the different cereal
types without the need for extensive cleaning
of equipment. Switching between
mutually-incompatible water- and solventbased
formulations is a particular problem
– it requires careful cleaning of equipment,
which can mean complicated planning and
can lead to time-pressure.
As we have seen, the quality of a seedtreatment
can be defined using a number
of parameters. But the overriding aim of
this process of optimization is to ensure
that the product gives consistent control of
the pathogen or pest, allowing optimal
seedling emergence and crop establish-
30 COURIER 2/06