For healthy potatoes - Bayer CropScience

ment. This can only occur if the recommended
(and registered) rate is applied
accurately. Careful calibration, maintenance
and operation of the seed-treatment
equipment are essential for achieving this;
but other factors also play a major role,
including the physico-chemical properties
of the product; and the technical purity of
the seed lot. The same parameters also
determine how evenly the seed-treatment
product is applied across the individual
seeds. It is often possible to trace back a
particular distribution pattern of a product
to a particular combination of personnel
and equipment. Graphical representation
of the measured coverage of hundreds of
individual seeds shows that a certain proportion
of seeds always receives either significantly
more, or significantly less than
the target amount. This means that under
practical conditions, every seed lot
inevitably contains a certain number of
over- or under-treated seeds. Even though
the safety margin that has been incorporated
into a product’s recommended application
rate means that problems rarely
arise in a crop grown from unevenlytreated
seed, the consequences of intentional
under-treating of seeds are often
underestimated.
Seed-treatment – an insurance
policy for the farmer
The pressure to continually decrease costs
in cereal production has led to a situation
in which various types of seed-treatment
product are available that differ not only in
terms of price, but also in terms of spectrum-of-action.
This necessitates careful
cost-benefit analysis: using a product containing
a single active substance – and thus
with a limited spectrum-of-action – is
probably appropriate for (apparently) noninfected
or only slightly-infected seeds
lots, although the risk remains difficult to
calculate. These products lack the versatility
of premium products, which tend to
maintain their broad activity even if unforeseen
bad weather occurs, or if the risk
of infection is higher than anticipated. The
potential for efficacy offered by broadspectrum
products under problematic conditions
represents a cost-benefit investment
that is probably unmatched by any
other crop protection measure.
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.
Achieving an optimal seed-treatment
that supports effective cereal cultivation
depends on the use of high-quality products:
these must show a spectrum-of-action
and technical properties that meet the most
demanding modern standards. ■
Distribution of seed-treatment product across 100 seeds with 100% application rate
Number of seeds
Distribution of seed-treatment product across 100 seeds with 80% application rate
Number of seeds
25
20
15
10
5
0
25
20
15
10
5
0
1 2 5 4
5
1 2 5 4
5
9
22
10
6
9
11
22
4
10
35 45 55 65 75 85 95 105 115 125 135 145 155 160
Coverage (%)
7
Fritz Brendler,
Chamber of Agriculture, North Rhine-Westphalia,
Crop protection service Bonn, Germany
6
4 3
2
35 45 55 65 75 85 95 105 115 125 135 145 155 160
Coverage (%)
11
4
7
3
4 3
2
acceptable limits
unacceptable limits
3
acceptable limits
unacceptable limits
1 1
1 1
In the first example, the amount of seed-treatment applied corresponded to 100%
of the recommended application rate. Here, 78% of seeds had a coverage that was
within acceptable limits (the region between 80 and 120 % coverage, blue bars).
In the second example, only 80% of the recommended application rate was applied.
The result: the proportion of seeds receiving coverage within the acceptable limits was
reduced almost by half, to 40%. Coverage was too low for the majority (58%) of seeds.
2/06 COURIER 31