Agriculture Reference
In-Depth Information
Main reason for this, primarily, were unfavorable weather conditions (drought stress and
high air temperatures) during two years of research. This is the main reason for great yield
variability among years. The highest mean root yield was 83.67 t ha
-1
in 2010, where during
the vegetation the largest amount of rainfall was registered. The smallest mean root yield was
achieved in 2012 and was about 51.15 t ha
-1
, in that year the amount of rainfall was below
long term average with unfavourable water distribution and higher mean air temperatures.
Achieved mean root yield in the favourable year (2010) was about 63.58% higher than the
mean root yield in the less favourable year (2012).
This data tells about very strong influence of weather conditions on sugar beets root
yield. An significant impact on the root yield had the protection of leaf disease caused by
C.
beticola
Sacc. On the treatment without fungicide application (variant 1), in research average,
the lowest root yield of 61.21 t ha
-1
was achieved. The yield reduction of beets on this
treatment, because of leaf damages in regard to the treatment with repeated fungicide
applications (variant 3), where was mostly little damages at the end of vegetation, was in
average about 15.92 t ha
-1
or 20.64%. Already one fungicide application (variant 2) reduced
leaf damages, so the yield reduction on variant 1 compared to variant 2 was about 8.70 t ha
-1
or 12.45%. These data show that by such agro-climatical conditions one fungicide application
is not enough. This is especially valid for humid years like 2010 where on treatments with
one application the root yield was lower by 13.86 t ha
-1
or 14.05% compared to treatments
with three applications. In the remaining two years the difference between variant 2 and
variant 3 was much smaller (about 4 t ha
-1
or by 6-7%). The differences in root yield and
between studied hybrids are significant. In research average, the highest root yield (78 t ha
-1
)
was achieved with the following hybrids: Boomerang, Colonia KWS and Sandor. At the same
time in the climatic favourable year 2010 with good protection against
C. beticola
Sacc. these
hybrids achieved high root yields - over 100 t ha
-1
. The lowest root yields on treatments
without fungicide application, in an three-years average, were achieved with hybrid Belinda
which is declared to be sensitive to
C. beticola
(55.77 t ha
-1
), but also with tolerant hybrids to
C. beticola
like Elvis (50.61 t ha
-1
), Gazeta (54.07 t ha-1) and Giraf (55.68 t ha
-1
).
Sugar Content
The average sugar content in sugar beets during all years of research and for all hybrids
was low and amounted only 14.88% (Table 3). Weather conditions had significantly affected
on sugar content in roots. The highest sugar content of 15.52% was achieved in 2012, in
which the lowest, only 13.93%, was achieved in 2010. During the research highest sugar
content average was achieved by hybrid Colonia KWS and amounted 15.40%. In the same
range, with no significant differences in sugar content, were two more hybrids (Asketa i
Boomerang). The lowest sugar content average during the research was achieved by hybrids
Sandor and Giraf.
Fungicide application significantly affected on sugar content. Lowest mean sugar content
of about 13.92% was achieved on treatments without fungicide application and highest mean
sugar content of about 15.53% was achieved on treatments with three fungicide applications.
With just one fungicide application against disease caused by
Cercospora beticola
Sacc. the
sugar content was, compared to the control, significantly increased, in average by 1.27%. The
largest increase was in humid 2010 and the average for all hybrids amounted 1.47%.
