Maize plant biomass at different hybrids, plant populations,
row spacings and soil conditions
Received for publication, March 27, 2014
Accepted, July 20, 2014
VIOREL ION1*, ADRIAN GHEORGHE BĂŞA1, GEORGETA TEMOCICO1,
GEORGETA DICU2, LENUŢA IULIANA EPURE1, DANIEL STATE2
1
University of Agronomic Sciences and Veterinary Medicine of Bucharest, Romania
2
SC Procera Agrochemicals Romania SRL, Romania
*Address correspondence to: University of Agronomic Sciences and Veterinary Medicine of
Bucharest, Faculty of Agriculture, 59 Marasti Blvd, District 1, Bucharest, Romania.
Tel./Fax: +40213 180 466; Email: viorelion@agro-bucuresti.ro
Abstract
Maize (Zea mays L.) is one of the most important crops for biomass production. The plant
biomass depends on growth factors among which the cultivated hybrid, plant population, row spacing
and soil conditions have a significant influence. The objective of this study was to determine the aboveground biomass of the maize plant and its components at different hybrids, row spacings, plant
populations, and soil conditions. For reaching this objective, field experiments were performed in two
locations from South Romania in 2013, at six maize hybrids (Cera 440, Cera 540, Flanker, ES Feria,
PR35T36, Janett) studied under three row spacings (75 cm, 50 cm, and twin-rows of 75/45 cm), three
plant populations (60,000, 70,000, and 80,000 plants per hectare), and two soil conditions (chernozem
and reddish preluvosoil). The determinations were performed in the early dough - dough plant growth
stage. The row spacing of 50 cm determined the highest dry biomass on maize plant. The increasing of
plant population determined a decreasing of dry biomass of the maize plant, as well as a decreasing of
moisture content. On reddish preluvosoil, dry biomass of maize plant registered smaller values than
those on chernozem soil and the whole plant and its components had less moisture content.
Key words: maize, biomass, moisture content, hybrid, plant population, row spacing, soil conditions.
1.
Introduction
Maize (Zea mays L.) is one of the most important crops for biomass production used
both as forage for animals, in particular beef and dairy cattle, and raw material for biogas
producing. Maize forage is an important source of energy for livestock animals (YILMAZ et
al. [1]). Also, maize is one of the most important crops for biomass production as source for
producing biogas (BASA et al. [2]).
Maize is generally cultivated in wide spaced rows (NIK et al. [3]). Reducing row
width to provide a more equidistant planting pattern has the potential to increase maize yield
and shift optimum plant population to a higher value depending on the interactions with
management and environmental factors (SANGOI [4]). An alternative to planting narrow
rows, while maintaining many of the benefits, is twin-rows (SATTERWHITE et al. [5]).
Twin-row planting systems in maize have been proposed as an alternative spatial
arrangement that should theoretically decrease plant-to-plant competition, alleviate crop
crowding stress and improve yields (ROBLES et al. [6]). Twin-row spacing as an alternative
planting practice for maize silage production leads to greater maize silage yields through
greater water use efficiency and faster canopy development (JONES [7]).
Maize hybrid selection and plant density are important management considerations
for successful forage production in dairy and livestock operations (CUSICANQUI & LAUER
[8]). Hybrid, population density and row spacing interact to influence whole-plant yield
(BARON et al. [9]). Plant density has significant effect on biomass yield as biomass yield
increased progressively with successive increase in plant density (AZIZ et al. [10]).
The biomass of maize plant is depending on a sum of growth factors among which the
cultivated hybrid, plant population, row spacing and soil conditions have a significant
influence on the accumulation of the above-ground biomass and its repartition between plant
components.
The objective of this study was to determine the above-ground biomass of the maize
plant and its components at different hybrids, row spacings, plant populations, and soil
conditions. It was also determined the plant moisture content and the percentage of dry
biomass on plant components. The determinations were performed in the early dough - dough
plant growth stage, which is the growth stage for harvesting the plants for producing silage as
forage for animals or raw material for producing biogas.
2.
Materials and Methods
Researches were performed in field experiments in 2013, in two locations from South
Romania, respectively Fundulea (44o28’ North latitude and 26o27’ East longitude) and Moara
Domneasca (44o29’ North latitude and 26o15’ East longitude).
The soil from Fundulea area is chernozem (cambic chernozem soil), with loam to clay
loam texture, pH between 6.4 and 6.8, and humus content between 2.8 and 3.2%. The soil
from Moara Domneasca area is reddish preluvosoil, with clay loam texture, pH between 6.2
and 6.6, and humus content between 2.2 and 2.8%.
Fundulea area is characterised by the average multiannual temperature of 10.7oC and
average multiannual sum of rainfall of 613.4 mm; in the period September 2012 – August
2013, the average temperature was of 12.0oC, and the sum of rainfall was of 700.6 mm.
Moara Domneasca area is characterised by the average multiannual temperature of 10.8oC
and average multiannual sum of rainfall of 553.6 mm; in the period September 2012 – August
2013, the average temperature was of 12.6oC, and the sum of rainfall was of 288.0 mm.
In the field experiments from Fundulea, six maize hybrids were studied, respectively:
Cera 440 (FAO precocity group 440), Cera 540 (FAO precocity group 540), Flanker (FAO
precocity group 450), ES Feria (FAO precocity group 550), PR35T36 (FAO precocity group
500), and Janett (FAO precocity group 550). The hybrids Cera 440 and Cera 540 are
specialised for grain production, hybrids Flanker and ES Feria are specialised for biomass
production, and hybrids PR35T36 and Janett can be used both for grain and biomass
production. In the field experiments from Moara Domneasca (on reddish preluvosoil), only
five maize hybrids were studied, respectively: Cera 440, Cera 540, Flanker, ES Feria, and
PR35T36.
Each hybrid was studied under three row spacings (75 cm, 50 cm, and twin-rows of
75/45 cm) and three plant populations (60,000, 70,000, and 80,000 plants per hectare).
The field experiments were performed in four replications. The number of variants
was 54 at Fundulea location and 45 at Moara Domneasca location. The sowing was
performed on 17th of April at Fundulea and on 26th of April at Moara Domneasca. Each
variant consisted in four lines with a length of 10 m (the total length for the four replications
was of 40 m). The cultivation technology was a regular one for South Romania, under rainfed
conditions.
In each location and from each variant a number of three maize plants were cut at soil
level and analyzed for determining the fresh biomass (above-ground biomass). The plants
were weighed directly into the field as total weight and weight per plant components,
respectively: leave blades; stalk, leave sheaths, and tassel; ear; husks. The components of one
maize plant for each variant were taken into the laboratory for determining the dry biomass
by oven drying at 80oC for 24 hours. The determinations were performed in the early dough dough plant growth stage, respectively on 5th of August at Fundulea (chernozem soil), and on
8th of August at Moara Domneasca (reddish preluvosoil).
An analysis of variance was performed for the dry biomass of the whole maize plant
and plant components at different row spacings, plant populations and hybrids.
3.
Results and Discussions
Dry biomass of maize plant and its components at different row spacings
(Figure 1). On chernozem soil, compared to the row spacing of 75 cm, the dry biomass of
maize plant components increased at 50 cm and twin-rows of 75/45 cm, the differences being
statistically significant for both variants. The most significant differences were registered for
ear and husks, while the smallest significant differences were registered for stalk, leaf sheaths
and tassel. Whether the dry biomass of maize plant components registered positive
differences statistically significant at 50 cm row spacing and twin-rows of 75/45 cm
compared to 75 cm row spacing, the total dry biomass of plant increased at 50 cm and at
twin-rows of 75/45 cm, but without statistically significant differences. The most important
increase of total dry biomass was registered at 50 cm row spacing.
Compared to the dry biomass on chernozem soil, the dry biomass on reddish
preluvosoil registered smaller values. Compared to values at 75 cm row spacing, the dry
biomass at 50 cm row spacing and twin-rows of 75/45 cm did not register any significant
differences either for plant components or for the whole plant. At 50 cm row spacing, the dry
biomass of the whole plant and the dry biomass of plant components registered very slight
positive differences compared to 75 cm row spacing, while at twin-rows of 75/45 cm the
differences were very slight negative.
Reddish preluvosoil
Chernozem soil
280.6
278.9
280.0
22.1
20.6
134.8
132.2
131.0
82.5
84.7
84.6
LSD 5% = 3.67
LSD 1% = 6.07
LSD 0.1% = 11.35
21.6
50
LSD 5% = 5.18
LSD 1% = 8.57
LSD 0.1% = 16.03
42.3
150
LSD 5% = 8.00
LSD 1% = 13.25
LSD 0.1% = 24.79
41.0
28.4 ***
LSD 5% = 22.57
LSD 1% = 37.35
LSD 0.1% = 69.91
200
42.2
Dry biomass (grams)
170.3 ***
168.3 ***
162.1
250
100
27.2 ***
102.6 *
100.8 *
LSD 5% = 6.44
LSD 1% = 10.66
LSD 0.1% = 19.96
23.9
50
43.1
100
LSD 5% = 10.18
LSD 1% = 16.85
LSD 0.1% = 31.53
88.9
150
LSD 5% = 1.77
LSD 1% = 2.93
LSD 0.1% = 5.49
46.4 **
200
LSD 5% = 35.94
LSD 1% = 59.47
LSD 0.1% = 111.32
350
300
LSD 5% = 29.28
LSD 1% = 48.45
LSD 0.1% = 90.69
250
47.6 **
Dry biomass (grams)
300
349.0
350
400
342.7
LSD 5% = 40.44
LSD 1% = 66.92
LSD 0.1% = 125.25
318.0
400
0
0
Leaf blades
Stalk, leaf sheaths
and tassel
Ear
Husks
Whole plant
Leaf blades
Stalk, leaf sheaths
and tassel
Ear
Husks
75 cm
50 cm
75/45 cm
Whole plant
Plant components
Plant components
75 cm
50 cm
75/45 cm
Figure 1. Dry biomass of maize plant and its components at different row spacings and on different
types of soils from South Romania, in the early dough - dough plant growth stage
Dry biomass of maize plant and its components at different plant populations
(Figure 2). On chernozem soil, compared to 60,000 plants per hectare, the dry biomass of
maize plant components registered negative differences statistically significant once with
increasing of plant populations at 70,000 and 80,000 plants per hectare. The smallest values
were registered at 80,000 plants per hectare. Also, the total dry biomass of the plant
registered negative differences statistically significant once with increasing of plant
populations, the smallest value being registered at 80,000 plants per hectare.
Compared to the dry biomass on chernozem soil, the dry biomass on reddish
preluvosoil registered smaller values and the same tendency, but with negative differences
statistically significant only at 80,000 plants per hectare, both for the dry biomass of plant
components and the whole plant.
The dry biomass of the ear seems to be the most affected by the increasing of plant
population, followed by the biomass of stalk, leaf sheaths and tassel.
The decreasing of dry biomass once with increasing of plant population is explained
by the increased competition among maize plant for growth factors, especially for water,
nutrients and solar radiation.
0
246.8 oo
307.9
284.9
17.1
25.2
LSD 5% = 5.85
LSD 1% = 9.68
LSD 0.1% = 18.12
22.1
116.0 oo
147.0
75.7 o
90.7
85.3
LSD 5% = 17.10
LSD 1% = 28.30
LSD 0.1% = 52.96
38.0 o
50
LSD 5% = 4.86
LSD 1% = 8.04
LSD 0.1% = 15.06
45.0
150
LSD 5% = 10.47
LSD 1% = 17.32
LSD 0.1% = 32.42
135.0
200
100
22.2 ooo
30.9
26.5 oo
250
42.5
Dry biomass (grams)
154.8 oo
88.2 o
107.6
96.5
LSD 5% = 2.40
LSD 1% = 3.98
LSD 0.1% = 7.44
43.5 oo
50
LSD 5% = 3.21
LSD 1% = 5.31
LSD 0.1% = 9.93
49.1
100
LSD 5% = 12.76
LSD 1% = 21.11
LSD 0.1% = 39.51
184.4
200
161.6 o
250
LSD 5% = 33.60
LSD 1% = 55.60
LSD 0.1% = 104.06
350
300
LSD 5% = 17.87
LSD 1% = 29.57
LSD 0.1% = 55.35
44.5 o
Dry biomass (grams)
300
Reddish preluvosoil
400
308.7 oo
350
150
372.0
LSD 5% = 29.97
LSD 1% = 49.60
LSD 0.1% = 92.83
329.0 o
Chernozem soil
400
0
Leaf blades
Stalk, leaf sheaths
and tassel
Ear
Husks
Whole plant
Leaf blades
Stalk, leaf sheaths
and tassel
Ear
Plant components
60000 plants/ha
70000 plants/ha
80000 plants/ha
Husks
Whole plant
Plant components
60000 plants/ha
70000 plants/ha
80000 plants/ha
Figure 2. Dry biomass of maize plant and its components at different plant populations and on
different types of soils from South Romania, in the early dough - dough plant growth stage
Dry biomass of maize plant and its components at different hybrids (Figure 3).
On chernozem soil, compared to the average of the six studied hybrids, the dry biomass of
stalk, leaf sheaths and tassel registered the largest variations, with positive differences
statistically significant for Flanker and ES Feria hybrids, and with negative differences
statistically significant for Cera 440 and Janett hybrids. Also, for leaf blades biomass, the
hybrids Flanker and ES Feria registered positive differences statistically significant, and the
hybrid Cera 440 registered negative differences statistically significant. The dry biomass of
ear and husks did not register any differences statistically significant. The dry biomass of the
whole plant registered positive differences statistically significant only at Flanker hybrid and
negative differences statistically significant at Cera 440 hybrid.
Compared to the dry biomass on chernozem soil, the dry biomass on reddish
preluvosoil registered smaller values. Compared to the average of the five studied hybrids on
reddish preluvosoil, positive differences statistically significant registered only Cera 540
hybrid for leaf blades and ES Feria hybrid for stalk, leaf sheaths and tassel, while negative
differences statistically significant registered only Cera 440 hybrid for stalk, leaf sheaths and
tassel.
The hybrids Flanker and ES Feria are specialised for biomass productions, which is
explaining the high values of dry biomass obtained by these two maize hybrids.
Percentage of dry biomass on maize plant components at different row spacings
(Figure 4). On chernozem soil, the percentage of the dry biomass of leaf blades registered the
highest value at 50 cm row spacing (13.7%), the percentage of the dry biomass of stalk, leaf
sheaths and tassel registered the highest value at 50 cm row spacing and at twin-rows of
75/45 cm (29.4%), the percentage of the dry biomass of ears registered the highest value at
twin-rows of 75 cm (51.2%), and the percentage of the dry biomass of husks registered the
highest value at 50 cm row spacing (8.1%).
On reddish preluvosoil, the percentage of the dry biomass of leaf blades, stalk, leaf
sheaths, and tassel registered the highest value at 75 and 50 cm row spacing (15.1% for leaf
blades and respectively 30.1% for stalk, leaf sheaths, and tassel). The percentage of the dry
biomass of ears registered the highest value at twin-rows of 75/45 cm (48.0%), and for husks
the highest value was registered at 75 cm row spacing (7.9%).
250
LSD 5% = 2.44
LSD 1% = 3.47
LSD 0.1% = 5.02
LSD 5% = 2.81
LSD 1% = 3.99
LSD 0.1% = 5.78
22.7
19.1
21.9
20.9
22.6
50
LSD 5% = 8.84
LSD 1% = 12.57
LSD 0.1% = 18.20
132.6
124.9
133.8
130.8
141.2
150
100
0
LSD 5% = 12.45
LSD 1% = 17.69
LSD 0.1% = 25.62
200
72.0 o
87.6
84.2
92.9 *
82.9
Dry biomass (grams)
LSD 5% = 4.78
LSD 1% = 6.70
LSD 0.1% = 9.46
28.7
25.5
29.4
25.1
22.3
28.2
50
83.0 ooo
100.0
110.0 ***
104.9 **
92.3 o
94.5
100
LSD 5% = 2.37
LSD 1% = 3.33
LSD 0.1% = 4.71
157.9
156.2
173.9
171.1
175.3
167.1
LSD 5% = 4.24
LSD 1% = 5.95
LSD 0.1% = 8.40
200
150
300
LSD 5% = 16.35
LSD 1% = 22.95
LSD 0.1% = 32.40
250
42.1 oo
48.4 *
48.9 *
44.8
44.7
45.3
Dry biomass (grams)
300
LSD 5% = 20.94
LSD 1% = 29.76
LSD 0.1% = 43.10
350
39.6
44.9 *
42.4
40.0
42.2
350
Reddish preluvosoil
400
266.9
276.6
282.3
284.5
288.9
LSD 5% = 17.59
LSD 1% = 24.69
LSD 0.1% = 34.85
311.6 oo
330.2
362.3**
345.8
334.5
335.1
Chernozem soil
400
0
Leaf blades
Stalk, leaf sheaths
and tassel
Ear
Husks
Whole plant
Leaf blades
Stalk, leaf sheaths
and tassel
Ear
Husks
Plant components
Cera 440
CERA 540
Flanker
ES Feria
Janett
Whole plant
Plant components
PR35T36
Cera 440
CERA 540
Flanker
ES Feria
PR35T36
Figure 3. Dry biomass of maize plant components at different maize hybrids and on different types of
soils from South Romania, in the early dough - dough plant growth stage
Reddish preluvosoil
Chernozem soil
100
100
7.9 %
8.1 %
90
90
80
80
70
51.2 %
49.1 %
48.8 %
60
50
40
30
27.7 %
29.4 %
29.4 %
20
10
13.6 %
13.7 %
13.6 %
Dry biomass (% of whole plant)
Dry biomass (% of whole plant)
7.5 %
70
7.9 %
7.6 %
7.2 %
46.9 %
47.1 %
48.0 %
30.1 %
30.1 %
29.9 %
15.1 %
15.1 %
14.9 %
75 cm
50 cm
60
50
40
30
20
10
0
0
75 cm
50 cm
75/45 cm
Distance between rows
Leaf blades
Stalk, leaf sheaths and tassel
Ear
Husks
75/45 cm
Distance between rows
Leaf blades
Stalk, leaf sheaths and tassel
Ear
Husks
Figure 4. Percentage of dry biomass on maize plant components at different row spacings and on
different types of soils from South Romania, in the early dough - dough plant growth stage
Percentage of dry biomass on maize plant components at different plant
populations (Figure 5). On chernozem soil, the percentage of the dry biomass of leaf blades
registered the highest value at 80,000 plants per hectare (14.1%), the percentage of the dry
biomass of stalk, leaf sheaths and tassel registered the highest value at 70,000 plants per
hectare (29.2%), the percentage of the dry biomass of ears registered the highest value at
80,000 plants per hectare (50.3%), and the percentage of the dry biomass of husks registered
the highest value at 60.000 plants per hectare (8.3%).
On reddish preluvosoil, the percentage of the dry biomass of leaf blades, stalk, leaf
sheaths and tassel registered the highest value at 80,000 plants per hectare (15.5% for leaf
blades and respectively 30.8% for stalk, leaf sheaths and tassel), while the percentage of the
dry biomass of ear and husks registered the highest value at 60,000 plants per hectare (47.8%
for ear and respectively 8.2% for husks).
Increasing of plant population determined an increasing of the percentage of the dry
biomass of vegetative components of the maize plant (leaf blades, leaf sheaths, and stalk)
both on chernozem soil and reddish preluvosoil. Concerning the percentage of the dry
biomass of ear, the increasing of plant population determined different effects according to
soil conditions. Thus, on chernozem soil the increasing of plant population determined a
decrease of the percentage of the dry biomass of ear at 70,000 plants per hectare and an
increase of the percentage of the dry biomass of ear at 80,000 plants per hectare. On reddish
preluvosoil, the increasing of plant population determined a decrease of the percentage of the
dry biomass of ear. Both on chernozem soil and reddish preluvosoil the increasing of plant
population determined a decrease of the percentage of the dry biomass of husks.
Chernozem soil
Reddish preluvosoil
100
8.3 %
100
7.2 %
8.0 %
80
70
49.5 %
50.3 %
49.2 %
60
50
40
30
28.9 %
28.4 %
29.2 %
20
10
7.7 %
6.8 %
47.8 %
47.4 %
46.8 %
29.4 %
29.9 %
30.8 %
14.7 %
14.9 %
15.5 %
60000 plants/hectare
70000 plants/hectare
80000 plants/hectare
90
13.3 %
14.1 %
13.6 %
Dry biomass (% of whole plant)
Dry biomass (% of whole plant)
90
8.2 %
80
70
60
50
40
30
20
10
0
0
60000 plants/ha
70000 plants/ha
80000 plants/ha
Plant population
Plant population
Leaf blades
Stalk, leaf sheaths and tassel
Ear
Husks
Leaf blades
Stalk, leaf sheaths and tassel
Ear
Husks
Figure 5. Percentage of dry biomass on maize plant components at different plant populations and on
different types of soils from South Romania, in the early dough - dough plant growth stage
Percentage of dry biomass on maize plant components at different hybrids
(Figure 6). On chernozem soil, the percentage of the dry biomass of leaf blades exceeded
14% only at Cera 540 hybrid (14.7%). The percentage of the dry biomass of stalk, leaf
sheaths, and tassel exceeded 30% at hybrids Cera 540 (30.1%), Flanker (30.2%) and ES Feria
(30.3%). The percentage of the dry biomass of ear exceeded 50% at hybrids PR35T36
(50.0%), Cera 440 (50.7%) and Janett (52.1%). The percentage of the dry biomass of husks
exceeded 8% at hybrids Flanker (8.0%), PR35T36 (8.3%) and Cera 440 (9.2%).
On reddish preluvosoil, the percentage of the dry biomass of leaf blades exceeded
14% at all the five studied hybrids. The percentage of the dry biomass of stalk, leaf sheaths,
and tassel exceeded 30% at hybrids Cera 540 (32.0%) and ES Feria (32.8%). The percentage
of the dry biomass of ear did not exceed 50% at any of the studied hybrids. The percentage of
the dry biomass of husks exceeded 8% only at hybrid Cera 440 (8.5%).
Moisture content of the maize plant and its components at different row spacings
(Figure 7). On chernozem soil, compared to the values obtained at 75 cm row spacing, at
50 cm row spacing the moisture content of the vegetative components of the maize plant (leaf
blades, leaf sheaths, and stalk) decreased, while the moisture content of the ear and husks
increased, as well as the moisture content of the whole plant. At twin-rows of 75/45 cm, the
moisture content of the leaf blades, leaf sheaths, stalk, tassel and husks decreased, as well as
the moisture content of the whole plant, but the moisture content of the ear increased.
On reddish preluvosoil, compared to the values obtained at 75 cm row spacing, at
50 cm row spacing the moisture content of all the plant components as well as of the whole
plant decreased, and the values decreased even more in the conditions of twin-rows of
75/45 cm.
Chernozem soil
Reddish preluvosoil
100
7.7 %
100
6.7 %
7.2 %
8.0 %
90
90
80
80
70
47.5 %
50.7 %
49.5 %
48.2 %
52.1 %
50.0 %
60
50
40
30
30.1 %
26.6 %
30.2 %
30.3 %
28.1 %
27.7 %
20
10
14.7 %
13.5 %
13.6 %
44.8 %
70
49.7 %
7.6 %
7.2 %
47.5 %
45.8 5
29.8 %
32.8 %
28.6 %
14.8 %
7.7 %
48.9 %
60
50
40
32.0 %
30
27.0 %
20
10
13.6 %
13.5 %
13.0 %
6.8 %
8.5 %
8.3 %
Dry biomass (% of whole plant)
Dry biomass (% of whole plant)
9.2 %
0
14.9 %
16.4 %
15.1 %
14.1 %
Cera 440
CERA 540
Flanker
ES Feria
0
Cera 440
CERA 540
Flanker
ES Feria
Janett
PR35T36
Maize hybrid
Leaf blades
Stalk, leaf sheaths and tassel
Ear
PR35T36
Maize hybrid
Husks
Leaf blades
Stalk, leaf sheaths and tassel
Ear
Husks
Figure 6. Percentage of dry biomass on maize plant components at different maize hybrids and on
different types of soils from South Romania, in the early dough - dough plant growth stage
Chernozem soil
40
30
62.3
65.5
63.6
63.1
67.7
50.9
50.4
50
63.6
73.6
75.8
66.1
60.0
60
49.3
50
62.7
70
Moisture content (%)
70.7
80
69.2
70.4
77.5
52.5
51.6
60
51.4
Moisture content (%)
70
75.3
77.1
70.2
74.0
73.5
79.4
90
80
81.1
90
80.6
100
74.3
Reddish preluvosoil
100
40
30
20
20
10
10
0
0
Leaf blades
Stalk, leaf sheaths
and tassel
Ear
Husks
Whole plant
Leaf blades
Stalk, leaf sheaths
and tassel
Ear
Husks
75 cm
50 cm
75/45 cm
Whole plant
Plant components
Plant components
75 cm
50 cm
75/45 cm
Figure 7. Moisture content of the maize plant components at different row spacings and on different
types of soils from South Romania, in the early dough - dough plant growth stage
Moisture content of the maize plant and its components at different plant
populations (Figure 8). On chernozem soil, the increasing of plant population decreased the
values of moisture content at all the plant components, including the whole plant.
On reddish preluvosoil, the increasing of plant population decreased the values of
moisture content at all the plant components except the ear moisture content, which increased
with the increasing of plant population. Regarding the moisture content of the whole plant, it
decreased with the increasing of plant population.
Moisture content of the maize plant and its components at different hybrids
(Figure 9). On chernozem soil, the smallest values for moisture content of all the plant
components as well as for the whole plant were registered at Flanker hybrid. The highest
values of the moisture content were obtain for the vegetative components of the maize plant
(leaf blades, leaf sheaths, and stalk) at hybrid Cera 440 hybrid, for the husks at Janett hybrid,
and for the ear and the whole plant at ES Feria hybrid.
On reddish preluvosoil, the smallest values for moisture content of leaf blades and
husks, as well as of the whole plant were obtained at PR35T36 hybrid, while the smallest
values for moisture content of stalk, leaf sheaths, tassel, and ear were obtained at Flanker
hybrid. The highest values for moisture content of leaf blades were obtained at Cera 440
hybrid, for moisture content of stalk, leaf sheaths, and tassel were obtained at Cera 540, while
for ear, husks as well as for the whole plant were obtained at ES Feria hybrid.
Chernozem soil
40
30
61.9
65.0
64.4
61.5
68.2
50.4
64.7
72.6
75.9
40
30
20
20
10
10
0
65.5
50
50.3
60
49.8
50
58.4
Moisture content (%)
70
65.0
80
69.2
71.0
50.3
52.6
60
52.5
Moisture content (%)
70
70.0
75.8
78.0
76.1
80.3
70.9
72.8
80.9
90
80
79.9
90
74.0
100
75.1
Reddish preluvosoil
100
0
Leaf blades
Stalk, leaf sheaths
and tassel
Ear
Husks
Whole plant
Leaf blades
Stalk, leaf sheaths
and tassel
Ear
Husks
Plant components
60000 plants/ha
70000 plants/ha
Whole plant
Plant components
60000 plants/ha
80000 plants/ha
70000 plants/ha
80000 plants/ha
Figure 8. Moisture content of the maize plant components at different plant populations and on
different types of soils from South Romania, in the early dough - dough plant growth stage
40
30
50
Husks
Whole plant
40
30
20
20
10
10
0
65.4
63.0
61.2
64.6
60.5
60
63.2
65.5
61.7
66.9
61.5
50
70
48.9
52.3
46.2
56.6
46.9
60
80
Moisture content (%)
49.8
52.9
48.1
58.1
52.6
49.5
Moisture content (%)
70
70.3
71.6
67.7
72.4
70.6
67.8
77.8
78.7
72.1
78.1
80.3
72.9
81.3
81.0
78.5
81.5
81.1
78.7
90
80
73.8
73.3
71.4
72.2
72.9
71.9
90
67.2
65.6
63.5
68.2
59.5
Reddish preluvosoil
100
74.4
75.6
73.5
75.4
74.0
Chernozem soil
100
0
Leaf blades
Stalk, leaf sheaths
and tassel
Ear
Husks
Whole plant
Leaf blades
Stalk, leaf sheaths
and tassel
Ear
Plant components
Cera 440
CERA 540
Flanker
ES Feria
Janett
PR35T36
Plant components
Cera 440
CERA 540
Flanker
ES Feria
PR35T36
Figure 9. Moisture content of the maize plant components at different maize hybrids and on different
types of soils from South Romania, in the early dough - dough plant growth stage
Dry biomass and moisture content of the maize plant and its components on
different types of soils, as average values (Figure 10). As average values for all the studied
hybrid and in all experimental conditions, respectively at different row spacings and at
different plant populations, the dry biomass of the whole plant was of 336.6 g on chernozem
soil and of 279.8 g on reddish preluvosoil.
The moisture content of the whole plant, as well as of the all plant components is
smaller on reddish preluvosoil than on chernozem. Thus, the moisture content of the whole
plant on chernozem was of 70.1% while on reddish preluvosoil was of 63.8%.
On the two soil conditions, the moisture content of plant components varied between
63.0 and 72.6% for leaf blades, between 74.6 and 80.3% for stalk, leaf sheaths and tassel,
between 50.2 and 51.8% for ear, and between 64.8 and 70.1% for husks.
97.4
26.5
Ear
70.1
64.8
51.8
40
30
20
Leaf blades
Stalk, leaf sheaths
and tassel
50.2
50
0
0
Leaf blades
63.8
80.3
72.6
63.0
60
10
21.4
45.7
41.8
100
83.9
150
70
Moisture content (%)
166.9
200
132.7
250
50
80
74.6
336.6
300
Dry biomass (grams)
90
279.8
350
76.6
100
400
Husks
Stalk, leaf sheaths
and tassel
Whole plant
Ear
Husks
Plant components
Plant components
Plant biomass on chernozem soil
Plant biomass on reddish preluvosoil
Whole plant
Biomass moisture content on chernozem soil
Biomass moisture content on reddish preluvosoil
(a)
(b)
Figure 10. Dry biomass (a) and moisture content (b) of maize plant components on different types of
soils from South Romania, as average values in early dough - dough plant growth stage
Percentage of dry biomass on maize plant components at different types of soils,
as average values (Figure 11). As average values for all the studied hybrids and in all
experimental conditions, respectively at different row spacings and at different plant
populations, compared to values obtained on chernozem soil, on reddish preluvosoil the
percentage of dry biomass of leaf blades, leaf sheaths, stalk, and tassel increased, while the
percentage of dry biomass of ear and husk decreased.
On the two soil conditions, the percentage of dry biomass varied between 13.6 and
15.0% for leaf blades, between 28.8 and 30.0% for stalk, leaf sheaths and tassel, between
47.3 and 49.7% for ear, and between 7.6 and 7.8% for husks.
Reddish preluvosoil
Chernozem soil
Husks
7.8 %
Ear
49.7 %
Husks
7.6 %
Leaf
blades
13.6 %
Stalk, leaf
sheaths
and tassel
28.8 %
Ear
47.3 %
Leaf
blades
15.0 %
Stalk, leaf
sheaths
and tassel
30.0 %
Figure 11. Percentage of dry biomass on maize plant components on different types of soils from
South Romania, as average values in the early dough - dough plant growth stage
4.
Conclusions
The row spacing of 50 cm determined the highest dry biomass on maize plant.
The increasing of plant population determined a decreasing of dry biomass of the
maize plant, as well as a decreasing of moisture content.
Compared to the dry biomass of maize plant on chernozem soil, the dry biomass on
reddish preluvosoil registered smaller values, these being also the effect of less amount of
rainfall registered in the area with reddish preluvosoil. Also, on reddish preluvosoil all plant
components as well as the whole plant registered a less moisture content.
The specialised hybrids for biomass productions (Flanker and ES Feria) produced the
highest values of dry biomass on plant.
Compared to the values obtained on chernozem soil, on reddish preluvosoil which
was associated with less favourable growing conditions the percentage of the dry biomass of
vegetative components of the maize plant (leaf blades, leaf sheaths, and stalk) increased,
while the percentage of the dry biomass of ear and husks decreased. Also, an increasing of
plant population determined an increasing of the percentage of the dry biomass of vegetative
components of the maize plant (leaf blades, leaf sheaths, and stalk) both on chernozem soil
and reddish preluvosoil.
The average percentage of the dry biomass of the ear from total plant was of 49.7 on
chernozem soil, and it was of 47.3% on reddish preluvosoil.
Both on chernozem soil and reddish preluvosoil, the most moisture plant components
were the stalk, leaf sheaths, and tassel, while the less moisture plant components were the
ears.
5.
Acknowledgements
The researches carried out for the elaboration of the present paper were financed by
Romanian Program “Partnerships for Priority Domains”, project PN-II-PT-PCCA-2011-3.21778 “OPTImization of BIOMass and Approach to Water conservation” (OPTIBIOMA-W),
Contract no. 45/2012.
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