of estimated indicators dealing with planting time period, the first time period of
planting having the covering depth of 9 cm was marked by the largest number of stems
(11.8 pcs.), also the first time period with the covering depth of 12 cm showed a little
lesser number (11,5 stems).
In general, the second time period of planting showed smaller results in terms of
stems' number. For example, the variant having the covering depth of 9 cm amounted
to only 10.4 pcs. Other variants of the second period were marked by an even smaller
number of stems of 8.8 and 9.4 pcs. The highest values in number of stems in the third
time period were noticed in the variant with the rhizomes' covering depth of 9 cm,
while in other variants, there were only 7.9 and 9.0 pcs.
A leaf is one of the main organs of the plant that occupies a lateral position on the
stem and serves for photosynthesis, transpiration and gas exchange. The number of
leaves on the main stem makes it possible to form a photosynthetic apparatus that shall
contribute to the accumulation of biomass. Proceeding from the results of evaluated
indicators, the greatest number of leaves per a stem was noted during the study of the
first planting period at the depth of 9 cm and comprised 14.2 pcs. Other variants of the
covering depth of the first planting period, as well as the variants of the second planting
period, were marked by similar values of leaf number, which in total were about 14.0-
14.5 pcs. The number of leaves in the third time period of planting showed the smallest
number in all variants of the covering depth, compared with the first and the second
time periods, and made up only 12.3-13.3 pcs.
A stem diameter provides for stem's strength and yield formation during the stage
of biomass wilting. The largest diameter value – 11.5 mm – was registered in the first
period with the covering depth of rhizomes 9 cm. The second time period of planting
(for different variants of rhizomes' covering depth) is marked by lower figures, which
can lead to yield's lodging. Also, the stem's strength may be promoted by the indicator
of internodes’ number, which was also noticed during the first period of planting, and
in particular for rhizomes' covering depth of 9 cm and amounted to 7.3 pcs.
Since this is a perennial plant, whose grassy stems are cut annually and the
rhizome remains in the soil, and after a certain period of rest, growth and vegetation is
restored, giving rise to the development of new plants, Giant Miscanthus is able to
grow in one place for quite a long time - up to 20 years, with 15 years of commercial
usage. In the winter, under the influence of low temperatures without snow cover, the
rhizome is damaged especially in the first year of overwintering, which is extremely
dangerous for the further spring's restoration of vegetation.
Thus, according to analyzed biometric parameters of Giant Miscanthus in terms
of planting time period and covering depth's variants, the first time period of planting
with the rhizomes' covering depth of 9 cm is characterized by the highest values of the
biometric indices, which in the future will form biomass productivity.
- 55 -