stems begin to wilt. In this period, the maturation of biomass occurs. Nutrients from
the leaf-stem mass are transported to the rhizome, where they accumulate, contributing
to overwintering of parent rhizomes.
Duration and transition from one stage to another is the vegetation period, which
(according to observations) is marked by a different number of days.
As is was analyzed, the first time period showed the maximal value of vegetation
period among the variants, namely, for the covering depth of 9 cm, it was somewhat
lesser than 186 days. Also the first time period's variant with the covering depth of 6
cm is illustrative. The vegetation period of the second time period, compared to the
first one, was marked by a smaller number of days, namely, at the rhizomes' covering
depth of 9 cm, it took 183 days, whereas this same time for the depth of 12 cm was
only 169 days. However, such a pattern does not provide sufficient biomass formation.
The vegetation period in the third time period is marked by an even smaller number of
days compared to the first and second time periods, but the largest number of days –
175 – was found for the depth of covering at 9 cm.
As a result of vegetation period's analysis in terms of growth and development
with the highest number of days, there was pointed out a variant with time of planting
in the second decade of April and rhizomes' covering depth of 9 cm.
Biometric and structural parameters depending on time and depth of
rhizomes' covering. All vegetative organs of plants are laid in the form of rhizomes'
buds. At germination, the first appears a root, which directs itself vertically into the
soil, and then comes out the sprout of a plant that grows above the soil's surface. For
some time the sprout uses nutrients of rhizomes, and after the emergence of seedlings,
plants move to their own root nutrition, form leaves and, through photosynthesis, form
organic substances necessary for their growth and development (Table 2).
Table 2 Biometric and structural indices of Giant Miscanthus plants depending
on time of planting and the (average data for 2016-2018)
Time
period of
planting
Rhizomes’
covering
depth, cm
Height of
the main
stem,
cm
Number of
leaves at the
main stem,
pcs.
Number of
stems,
pcs.
Stem
diameter,
mm
Number of
stem
internodes,
pcs.
І
6
242,5
13,1
9,4
11,4
7,2
9
254,8
14,2
11,8
11,5
7,3
12
239,6
14,8
11,5
11,3
7,1
ІІ
6
246,4
13,0
8,8
11,2
6,4
9
251,6
14,0
10,4
11,4
6,6
12
241,3
14,5
9,4
11,1
6,2
ІІІ
6
241,6
12,3
7,9
10,8
6,0
9
237,8
13,0
9,8
11,0
6,1
12
229,3
13,3
9,0
10,7
5,9
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