International Journal of Agriculture and Crop Sciences.
Available online at www.ijagcs.com
IJACS/2013/5-2/109-114
ISSN 2227-670X ©2013 IJACS Journal
The determination of plant density on dry matter
accumulation, grain yield and yield components of
four maize hybrids
Mehdi sadeghi
Department of Agronomy, Dezful Branch, Islamic Azad University, Dezful, Iran
Corresponding author email: [email protected]
ABSTRACT: The effects of plant density on dry matter accumulation, grain yield and yield components of
four maize hybrids were evaluated. The experimental design was split plot format based on a randomized
complete block with three replications. The study was conducted of Islamic Azad University of Dezful
(Iran) farming research station in 2010. The main factors were 4 levels of hybrids (Ks.c704, Ks.c700, K78
and K47) and plant densities 7, 8, 9 and 10 plants m-2 were used as sub-plot. The result showed with the
increasing plant density of the whole hybrids increased amount of redistribution of dry matter. Because of
increasing plant density were shade leaves high up on leaves and accelerate aging and was reduced its
current photosynthesis. The maximum redistribution was obtained in hybrid KSC704 and 10 plant density.
Results showed that the hybrid, density and their interactive on grain yield, total dry matter, 1000 seed
weight and harvest index were significant. However, the number of rows per ear was not affected
significantly by the plant density. Hybrid of Ks.c704 had the highest grain yield (8450 kg ha-1) due to
greater leaf area index and its delayed durability compared to other hybrids. Highest grain yield for the
same hybrid was obtained at plant density of 8 plants m-2. Both Ks.c700 and Ks.c704 hybrids at plant
density of 8 plants m-2 reached their maximum grain yield and increased density in the grain yield and
yield components. Therefore, the combination of KS.c704 hybrid at plant density of 8 plants m-2 was the
best option to achieve the highest grain yield.
Keywords: Grain yield, Plant density, Redistribution, Yield component.
INTRODUCTION
Grain weight one of the yield components of the maize plant was genetically influenced characteristics of
number of grains per ear, grain competition, grain filling period, grain filling rate, rate of dry matter accumulation
and environmental conditions before and after the anthesis (Lopez, et al,2008). Stress conditions such as high density
can be due to decreased photosynthesis due to leaf shading on each other and increased storage dry materials
(Dwyer,et al.,1991). Ehdaei et al., (2006) reported that high density has accelerated aging leaves and reduced
photosynthesis rate and in turn stimulates the redistribution of dry materials stored in the grain (Ehdaie, et al. 2006).
Schuler and Vestage (1994) stated that the potential of the plant in accumulated amount of dry matter in
vegetative organs necessarily mean high Potential not redistribute this material and factors such as the capacity of
grain one of the key importance in redistributing material from vegetative organs to grain (Schussler and Westage,
1994).
The response of maize hybrids (zea mays L.) to plant population is different. Increased plant density
results in higher grain yield per unit area (Sangio, et al., 2002). Tokatilids (2004) reported that improving grain yield due
to increased plant population was achieved on a narrow spectrum (Tokatlidis and Koutroubas, 2004). Grain yield results
from the increased pollen-to-silking interval and the fallowing barrenness reduced at higher plant population
(Borras, et al., 2003). Higher grain yield produced due to higher plant density (Fulton. 1970 and Hokalipour, 2010). Griesh
(2001) reported that plant population densities from 5 to 5.6 plants m-2 were considered optimal (Grish and Yakut,
2001). However Rahmati (2009) reported that the optimal density for acquiring higher corn grain yield was 7.5 plants
m-2 (Rahmati, 2009). Other researches (Danial, 2003) indicated that optimal plant density ranged from 5 to 8 plants m-
Intl J Agri Crop Sci. Vol., 5 (2), 109-114, 2013
2
(Danial, 2003). Greater plant densities result in lower yields due to of competition for water, light and nutrients
between plants (Sarlangue, 2007). Response of Maize to plant density in row is more than row space. More densities
lead to low rates of seed production as a result of competition for light and humidity (Turget, 2005).
Maize grain yield per unit area shows a curvilinear response to plant population. For each production system, there
is a population that optimizes the use of available resource, allowing the expression of maximum attainable grain
yield in that environment (Cox, 2001). The ideal plant number per area will depend on several factors, such as water
availability, soil fertility, hybrid maturity group and row spacing (Hashemidezfuli and Herbert. 1992). Tollenear, et al,
(1999) reported that the late maturity hybrids are less sensitive to plant density (Tollenear, et al, 1999).The higher
height of plant at grain filling, the lower sensitivity to plant density (Berzsenyi and Dang., 2006). Timl et al, (2001) stated
that hybrids with high grain filling period of more leaf area and leaf area index were correlated with grain yield (Timl
et al, 2001).
The objectives of this study were to evaluate the impact of different plant densities of maize hybrids on dry matter
accumulation, yield and yield components.
MATERIALS AND METHODS
A field excrement was conducted at Dezful Research Farm of Azad University Khozestan, Iran (32º22 N
latitude, 48º32 E) in 2008 growing season. Soil pH was 7.5 and soil texture was clay loamy. This research was
arranged as split –plot design based on randomized complete block design with three replications. Main plots were
assigned to hybrids of corn (Ks.c704, Ks.c700, K47 and k78) and subplots to plant population densities (7, 8. 9 and
10 plants m-2). Prior to seed sowing 100 kg ha-1 phosphorus in form of super phosphate triple and 250 kg ha-1
nitrogen in form of urea were broadcasted and incorporated into the soil. Fifty percent of urea was used at sowing
time and residual was applied as top dress at 4-6 leafy stage.
Corn seeds were disinfected and sown by hand on July 10. Irrigation was performed after sowing. Plots
were kept free of weeds, insects and diseases. The plots were 8 meter long and consisted of eight rows, 0.75 m
apart. The space between blocks was 2 m and between each plot was 1 m was apart.
Samples consisted of a 2 m2 area of center of row of each plot after leaving two rows in the border areas
were hand harvested at physiological maturity stage. The six ears were separated in order to determine the seed
yield and yield components. Random samples were taken from each plot to determine seed and straw moisture,
seed yield, total dry matter and seed dry matter. These samples were Oven dried at 72ºC for 48 hours (19). Three
ears were harvested at each sampling, and 10 seeds from each ear were separated and each separately dried at
72 °C for 48. Physiological maturity and final harvest at the end of the yield with yield components were calculated
(Borras, et al., 2003).
In order to measure the redistribution of dry matter of appearance time Tassel each week, three plants
were harvested and determinates the dry weight relations were calculated amount and efficiency of redistribution
(Ehdaie, et al. 2006 and Lopez, et al, 2008).
Amount of redistribution (g.m-2) = Maximum dry matter in reproductive — Dry weight at physiological
maturity
The Portion redistribution (%) = the amount redistribution/ Grain yield ×100
The Efficient redistribution= the amount redistribution/ Maximum dry weight of reproductive ×100
The data was analyzed using the SAS (9, 1) software. When F-test was significant at P<0.05 level, Duncan’s
multiple range test was used to separate the means.
RESULT AND DISCUSSION
Amount redistribution of total dry matter
The effects of hybrid, plant density and their interactive effects on amount redistribution total dry matter
were significant (Table 1). Mean of comparison of total dry matter showed that Ks.c704 and Ks.c700 hybrids had
the highest redistribution of total dry matter of plants 156.6 and 153.2 g m-2 respectively and the lowest total dry
matter 130.1 and 107.1g m-2 for k47 and k78 hybrids respectively (Table 2). Genetic differences between hybrids
such as leaf area index, plant height and maturity could lead to differences in the amount of dry matter
redistribution. It seems to be higher dry matter production and grain yield in hybrids more than 704 leading part in
the redistribution (Austin, 1980). The researchers reported that high photosynthetic capacity in Ks.c704 hybrids could
lead to an increased rate of late was their remobilization (Schussler and Westage, 1994).The lowest and highest of
amount redistribution total dry mater were obtained at 7 and 10 plants m-2 127.9 and 144.5 g m-2 respectively
(Table 2). The interactive effects plant density and hybrids showed that all hybrids at plant density of 10 plants m-2
110
Intl J Agri Crop Sci. Vol., 5 (2), 109-114, 2013
had the highest amount redistribution (Table 3). Plant density increased light interception into the plant canopy was
lower and thus causing environmental stress that the increased in the redistribution of dry matter. Reported that
increasing redistribution of dry matter under high density was observed in many crop. (Austin,1980 and Ehdaie, et al.
2006) Results of other researchers showed that with increasing plant density increased redistribution of dry matter
and there was a significant positive correlation (Dwyer,et al.,1991).
Portion redistribution of total dry matter
The effects of hybrid, plant density and their interactive effects on Portion redistribution total dry matter
were significant (Table 1). Mean of comparison of Portion redistribution showed that Ks.c704 and k47 hybrids had
the highest Portion redistribution of total dry matter of plants 17.7 and 17.5 percentages respectively and the lowest
Portion redistribution of total dry matter 17.2 and 15.2 percentage for Ks.c700 and k78 hybrids respectively (Table
2). The results showed that interactive effects in the plant density of 10 plants m-2 in SC704 had the highest
Portion redistribution, but the hybrids k78 in the density of 8 plants m-2, had the lowest Portion redistribution (Table
3). Reported that the redistribution Portion dry matter increased under environmental stress (Ehdaie, et al. 2006 and
Schussler and Westage, 1994).
Efficient redistribution of total dry matter
The effects of hybrid, plant density and their interactive effects on efficient redistribution total dry matter
were significant (Table 1). Mean of comparison of efficient redistribution total dry matter showed that Ks.c704 and
Ks.c700 hybrids had the highest efficient redistribution of total dry matter of plants 14 and 13.9 g m-2 respectively
and the lowest efficient redistribution total dry matter 11.5 and 10.5 g m-2 for k47 and k78 hybrids respectively
(Table 2). The lowest and highest of efficient redistribution total dry mater were obtained at 7 and 10 plants m-2
11.7 and 13.2 g m-2 respectively (Table 2). The interactive effects plant density and hybrids showed that all hybrids
at plant density of 10 plants m-2 had the highest efficient redistribution (Table 3). Other researcher reported that
increasing the density of a substance produced by photosynthesis and other physiological sink was limited and
therefore increased the allocation and redistribution of assimilates (Austin, 1980, Ehdaie, et al. 2006 and Schussler and
Westage, 1994).
Crop yield
The effects of hybrid, plant density and interactive affects their on grain yield were significant. Hybrid
Ks.c704 had the highest grain yield (865.2 g m-2) than other hybrids (Table 1 and 2). Timl, (2001) showed a
significant positive correlation between LAI with grain yield for hybrid S.c704 compared to other hybrids (Timl et al,
-2
-2
-2
-2
2001). Plant density 8 plants m (795.2 g m ), the highest grain yield and plant density of 7 plant .m (741.3 g m )
-2
of had the lowest yield (Table 2). Increase in plant density of 8 plants m appropriate plant density and optimum
use of space nutrition is without competition in plant canopy. The other Studies showed that Ks.c704 hybrid of grain
yield was higher. The highest levels of grain yield in plant density were 8 plants m-2. Due to the plant density of
grain yield components like number of rows, number of grains per ear and grain weight than other higher plant
density (Rahmati, 2009 and Hokalipour, 2010) .Gozubenli, et al, (2004) experimenting on various plant densities observed
corn grain yield increased with increasing plant density to 9 plants per m-2 and higher densities of the competition
for resources between plants decreased (Gozubenli, 2004). The interaction effects between hybrid and plant density
on yield was significant. Mean comparisons revealed that the hybrid and plant density of 8 plants m-2 with the
Ks.c704 hybrid (913.5 g m-2) had the highest grain yield. The Ks.c700 hybrid is also the highest yield compared to
the same density of 8 plants m-2(901.2 g m-2). While the two other hybrids means, k78 and k47 highest grain yield
at the highest density of 10 plants m-2 (Table 3). The reason for this is that the two hybrids (k78 and k47) a height
of less than two hybrids (Ks.c704 and Ks.c700) and also they were early maturity, and therefore the hybrids to
achieve high grain yield potential will require more plant density. Similar researches with increasing plant density 8
to 9 plant .m-2 increased grain yield (Echarte, 2000, Schussler and Westage, 1994, Tollenear, 1999 and Tokatlidis 2001).
The effect of hybrid on the number of rows per ear was not significant. This subject coordinated to the
genetic characteristics and showed genetic similarity in hybrids (Table1). Hashemidezfuli et al, (1992) indicated
that number of rows in ear was mainly genetically affected and the environment will be less affected. They also
showed no significant effect on the trait number of rows per ear (Hashemidezfuli and Herbert. 1992). The effect of plant
density on the number of rows per ear was not significantly but related to the maximum plant density of 8 plants m-2
(14.64) inverse plant density of 10 plants m-2 (14.52), respectively. Hashemidezfuli, et al, (1992) showed that the
plant density of the number of rows per ear no significant effect on the trait and the genetic trait is more to the
environment interaction effect plant density and hybrid on the number of rows per ear trait was not
significant(Hashemidezfuli et al.,1992). Other research reported that the number of row in ear on interaction effects plant
111
Intl J Agri Crop Sci. Vol., 5 (2), 109-114, 2013
density and hybrid was not significant (Tokatlidis, 2011). Boarrs (2003) showed that higher plant density reduced
number of rows per ear in whole hybrids their experiment (Borras, et al., 2003). Similarly Echart (2000) reported that
reduced number of rows per ear with plant density to 14 plant m-2 (Echarte, 2000).
Our results showed that effect hybrid and the interactive effect of hybrid and plant density of number of
seed in row in number of seed in row was significant (Table 1). Hybrids of Ks.c704 and Ks.c700 had the highest
(26.4 and 25.7) number of seeds in the row and k78 (23.2) had the lowest number of seed per row (Table 2). The
plant density effects on number of seed row showed that the plant density of 8 (28.8) and 10 plants m-2 (23.4) were
highest and lowest respectively (Table 2). Echart (2000) stated that increased plant density reduced the number of
seed in rows (Echarte, 2000). Expressed that increasing plant density up to 9.5 plants m-2, seed number of ear and
seed number per row should be lower than the number of rows per ear and 1000 grain weight. Turget (2005) and
Sarlango (2007) suggested that increasing plant density reduced the number of seeds in rows, and this caused a
significant decrease in yield (Sarlangue, 2007 and Turget, 2005). Our result showed that the maximum number of rows of
the Ks.c704 was plant density of 8 plants m-2 (27.4) and the lowest hybrid of the k78 was at the plant density of 10
plants m-2 (24.2). This suggested that the plant density was greater influence than the optimal number of seeds per
row (Table3). Other researches reported the increasing density from 4 to 8 plants m-2 reduced the number of seed
rows per ear and reduce the number of rows of seed slowly(Sarlangue, 2007 and Turget, 2005).
Results showed that the effects of hybrid, density and the interactive effects were significant on the 1000
weight seed (Table1). The Ks.c704 and Ks.c700 hybrids had highest (310 and 299 g) and k78 hybrid had the
lowest (259 g) 1000 weight seed (Table2). The late maturity hybrid due to greater opportunities for growth and dry
matter accumulation in the grain and the durability of the LAI of the seed weight than early maturity hybrids (Table
2). The most direct effect on grain yield had 1000 weight seed and it can be reason highest grain yield in the Ks.c
704 and Ks.c 700 hybrids be compared to other hybrids. Rahmati (2009) showed that the Ks.c 704 hybrid had
greater seed weight compared to other hybrids (Rahmati, 2009). Cox, et al,(2001) demonstrated that the hybrid with
late maturity with increasing growing period, seed weight was higher than other hybrids and hence higher yield
(Cox, 2001). The highest and lowest 1000 seed weight were obtained of plant density of 8 and 10 plants m-2 (288 and
261 g) respectively. This can be due to competition among plants for resources environmental that with increasing
plant density, seed weight was also reduced (Table 2). The results showed that interactive effects in the plant
density of 8 plants m-2 in SC704 and Ks.c700 had the highest yield, but the hybrids k47 and k78 in the highest
density of 10 plants m-2, had the highest yield. Because height of plant of two hybrids (k47 and k78) was smaller
than hybrid (Ks.c704 and Ks.c700) the greater plant density to achieve maximum yield (Table 3). Turget (2005)
reported that early maturity hybrids with increasing plant density compare to lately maturity had the lowest
1000seed weight (Turget, 2005).
The effects of hybrid, plant density and their interactive effects on total dry matter were significant (Table 1). Mean
of comparison of total dry matter showed that Ks.c704 and Ks.c700 hybrids had the highest total dry weight of
plants 2015.5 and 1975.3 g m-2 respectively and the lowest total dry matter 1862.7 and 1910.2g m-2 for k47 and
k78 hybrids respectively (Table 2). Its seems that the longer growth periods was responsible for the higher total dry
matter of these two hybrids. The lowest and highest of total dry mater were obtained at 7 and 10 plants m-2 1810.4
and 2033.3 g m-2 respectively (Table 2). The interactive effects plant density and hybrids showed that all hybrids at
plant density of 10 plants m-2 (Table 3). Cox et al (2001) indicated a positive correlation between yield and dry
matter accumulation in different maize hybrids (Cox, 2001). Sarlango (2007) and Turget (2005) reported that
maximum dry matter was obtained at density of 7.9 plants m-2 (Sarlangue, 2007 and Turget, 2005).
Hybrid and plant density effects on harvest index were significant (Table 1). The Ks.c704 hybrid had
highest harvest index (42.9%) and other hybrids of Ks.c700, k47 and k78 were (42.2, 39.5 and 38.9, respectively).
A positive correlation between economic grain yield and biological yield suggests that high index reflects the yield
of each hybrid could be higher than the hybrid in the grain yield obtained from Ks.c704 hybrid. This can be due to a
larger leaf area index and more leaf area durable as well as factors that increase the harvest index. The lowest
harvest index (36.8%) was obtained at high plant density of 10 plants .m-2 and harvest index was higher (41.2%)
for plant density of 8 plants m-2. Reduction in plant density, higher harvest index, resulting from increased plant dry
matter can be attributed to a negative relationship between biological yield and harvest index (Table 2). Interactive
effects of harvest index were significant (Table 1). The Ks.c704 hybrid and the plant density of 8 plants m-2 had the
highest of harvest index. This can be due to a larger leaf area, leaf area index and yield strength compared to the
optimal plant density, the same 8 plants per m-2 can take advantage of all the environmental and economic yield
benefits to be closer to its grain yield potential. The two hybrid k47 and k78 due to short plant height and more
early maturity in its highest plant density is the same as 10 plants per m-2 have been able to reach the highest
harvest index and grain yield. These results confirm the notion that the more early maturity hybrids, leaf area and
plant height is reduced to achieve higher yield, should be plant densities. Tollenear (2002) reported that the
112
Intl J Agri Crop Sci. Vol., 5 (2), 109-114, 2013
increase in maize grain yield due to biological yield of most of the increase (Tollenear, 2002). Boarrs (2003), Turget
(2005), Sarlango(2007) and Rahmati (2009) stated that lower harvest index with increased plant density for maize
hybrids. Our results reported clearly indicated that the hybrid ksc704 with plant density 8 plants m-2 had the highest
yield (Borras, et al., 2003, Rahmati, 2009, Sarlangue, 2007 and Turget, 2005).
Table1. The effects of hybrids and different plant density on some ergonomic trait of maize hybrid
S.O.V
df
Amount
redistribution
Replicatio
n
2
139.2
Hybrid(H)
3
1344.9
Eroor1
6
.011
Density(D)
9
12709.7
H× D
3
66.48
Eroor2
(%CV)
24
-
608.5
4.71
ns
*
*
*
Portion
redistributi
on
Efficient
redistributi
on
290.29
623.6
11.26**
10.1**
0.511
32.90**
0.411
80.47**
9.625**
4.86**
604.46
5.12
12.66
7.31
Total
Dry
Matter
Grain
Yield
66.3
ns
493.1
309404.1
**
395.8
*
2.8
84215.9
*
*
8641.2
215.7
5.85
**
487.5
8.31
ns
*
*
698.1
*
63725.3
**
26859.8
498.5
Seed
Weigh
t
55.6
Numb
er of
Seed
in Row
3.7
*
ns
74.5
3.91
Numb
er of
Seed
in Ear
0.32
*
35.8
3.17
*
4.2
5.57
5.2
48.3
695.5
0.451
**
3.87
8.11
7.48
**
n
13.5
0.221
9.71
9.5
6.22
ns
82.1
**
0.775
422.8
s
Harvest
Index
2.9
13.9
ns
0.056
*
ns
n
s
3.89
27.6
ns
0.911
**
1000Se
ed
Weight
**
**
8.38
**
0.843
*
0.481
8.86
*, **Significant at the 0.05 and 0.01 probability levels, respectively.
Table2. comparison of mean effect plant density on some agronomic traits of maize hybrids
Amount
redistribution
-2
(g m )
Treatment
Hybrid
Ks.c704
Ks.c700
K78
K47
plant Density
2
(plant. m- )
7
8
9
10
portion
redistribution
(%)
a
17.7
ab
17.2
b
15.2
a
17.5
d
16.5
b
16.4
b
16.5
a
17.9
156.6
b
153.2
d
107.1
c
130.1
127.9
c
134.3
b
140.3
a
144.5
Efficient
redistribution
(%)
Seed
Weight
(mg)
Grain
Yield
(kg ha
1
)
Number
of Row
in Ear
Number
of Seed
in Row
a
14.0
a
13.9
b
10.3
b
11.5
a
28.3
b
22.0
c
20.0
c
21b
a
8450.2
b
8141.0
d
7021.0
c
7352.0
a
14.9
a
14.8
a
14.2
a
14.4
a
26.4
a
25.7
c
23.6
b
24.5
b
11.7
c
12.2
b
12.7
a
13.2
d
18.6
a
20.8
a
21.0
a
22.0
b
7213.0
a
7752.0
b
7426.0
c
7328.0
d
14.5
a
14.6
a
14.5
a
14.4
a
28.4
a
28.6
b
22.9
b
22.8
Total
Dry
Matter
-2
(g m )
Harvest
Index
(%)
a
1995.6
a
1945.3
c
1812.6
b
1866.1
a
1775.4
b
1889.9
ab
1941.3
a
1985.9
1000
Seed
Weight
(g)
a
43.3
a
41.8
c
38.7
b
39.3
a
305.0
b
294.0
c
254.0
c
262.0
a
c
40.6
a
41. 0
b
37.3
b
36.6
a
273.0
a
285.0
b
270.0
c
256.0
b
For given means within each column followed by the same letter are not significantly (p<0.05)
Table3.Interaction effects of plant density on some agronomic traits of hybrids corn
Hybrid
Ks.c704
Ks.c700
K78
K46
Plant
Density
(plant
2
m- )
7
8
9
10
Amount
redistribution
-2
(g m )
7
8
9
10
142.5
bc
150.6
ab
158.7
a
161.1
7
8
9
10
7
8
9
10
120.7
d
125.8
cd
134.1
c
139.7
portion
redistribution
(%)
Efficient
redistribution
(%)
Grain
Yield
-1
(kg ha )
bc
17.2
cd
16.8
bc
17.7
a
19.2
c
13.2
bc
13.8
b
14.2
a
14.8
c
16.5
cd
16.4
c
17.1
b
18.7
cd
13.2
bc
13.6
b
14.2
a
14.7
100.2
f
104.8
ef
109.1
e
114.3
f
14.7
e
14.9
ef
14.8
d
16.4
f
9.5
g
10.1
f
10.5
ef
10.9
7005.0
d
7349.0
dc
7582.0
dc
7849.0
de
17.5
bc
17.6
bc
17.4
b
17.7
bc
10.7
e
11.3
de
11.8
d
12.2
ef
7195.0
cd
7455.0
cd
7975.0
bc
8206.0
148.4
b
156.2
ab
159.3
a
162.7
Number
of Row
in Ear
Number
of Seed
in Row
c
8713.0
a
9135.0
bc
9061.0
b
8975.0
c
14.8
a
14.9
a
14.5
a
14.4
a
27.3
a
27.4
ab
27.2
b
27.1
c
8464.0
ab
9012.0
b
8835.0
c
8625.0
bc
14.6
a
14.6
a
14.5
a
14.4
a
27.1
ab
27.2
bc
26.9
bc
26.3
e
14.1
a
14.1
a
14.2
a
14.2
a
24.1
cd
24.2
cd
24.3
cd
24.5
d
14.1
a
14.2
a
14.2
a
14.3
a
24.2
cd
24.3
cd
24.5
c
24.7
h
ab
Total
Dry
Matter
-2
(g m )
c
2080.7
b
2116.2
ab
2175.3
a
2205.6
b
2061.6
b
2104.2
ab
2127.3
ab
2140.3
e
1893.2
d
1967.6
bc
2019.1
bc
2048.1
d
1925.1
d
1994.7
bc
2038.2
bc
2089.4
Harvest
Index
(%)
ab
41.8
a
43.1
b
41.5
bc
40.6
c
40.3
a
42.8
b
41.4
bc
40.0
e
36.2
c
37.2
c
36.9
bc
37.9
d
36.7
c
36.8
bc
38.7
bc
38.9
1000
Seed
Weight
(g)
ab
303.0
a
308.0
b
298.0
b
293.0
bc
299.0
ab
307.0
bc
290.0
bc
283.0
b
d
238.0
d
248.0
cd
262.0
c
268.0
c
250.0
cd
258.0
c
270.0
bc
276.0
e
cd
For given means within each column followed by the same letter are not significantly (p<0.05)
113
Intl J Agri Crop Sci. Vol., 5 (2), 109-114, 2013
REFERENCE
Austin RB, Morgan CL, Ford MA, Blackwell RD. 1980. Contributions to grain yields from pre-anthesis assimilation in tall and dwarf barley
phenotype in two contrasting seasons. Ann. Botany.45:309-319.
Berzsenyi Z, Dang QL. 2006. Effect of crop production factors on the yield and yield stability of maize (zea maize L.) hybrids. Acta Agron Hung,
54: 413-424.
Borras L, Maddonni GA, Otegui ME. 2003. Leaf Senescence in maize hybrids: plant population, row spacing and kernel set effects. Field crops
Research, 82: 13-26.
Cox WJ. 2001. Whole plant physiological and yield response of maize to plant density. Agronomy Journal, 88: 483-496.
Danial W, Paszkiewies SH. 2003. Plant population for maximum corn yield potential product in formation. Agronomy Journal, 8: 45-51.
Dwyer LM, Tolleanaar M, Stewart DW. 1991. Changes in plant density dependence of leaf photosynthesis of maize (Zea mays L.) Hybrids,
1985 to 1989. Can. J. Plant Sci. 71:1-11.
Echarte LS, Luque FH, Andrade VO, Sandras A, Cirilo M, Otegui E, Vega CRC. 2000. Response of maize kernel number to plant density in
Argentinean hybrids released between 1965 and 1993. Field crops Research, 68: 1-8.
Ehdaie B, Alloush GA, Madore MA, Wanies JG. 2006. Genotypic variation for stem reserves and mobilization in wheat. I: post anthesis changes
in internode dry matter. Crop. Sci. 46:735-746.
Fulton JM.1970. Relationship among soil moisture stress plant population, row spacing and yield of corn. Canadian Journal Plant Science,
50:31-38.
Gozubenli NW, Harrison MP, Dobbs RR. 2004. Corn response to twin and narrow rows. Agronomy Journal, 86: 359- 366.
Grish MH, Yakout GM. 2001. Effect of plant population density and nitrogen fertilization on yield and yield component of some white and yellow
maize hybrids under drip irrigation system in sandy soil. In Proceeding of the International Conference on Plant Nutrition-Food Security
and Sustainability of Agro-ecosystems, Madrid.Spain.pp:810-811.
Hashemidezfuli A, Herbert SJ. 1992. Intensifying plant density response of corn with artificial shade. Agronomy Journal, 84,547-551.
Hokalipour S, Seyedsharifi R, Somarin SJ, Hasanzadeh M, Janagard MS, Mahmoodabad RZ. 2010. World Applied Science Journal 8(9):115721162.
Lopez M, Bereny A, Hall AJ, Trapani N.2008. Contribution of pre-anthesis photo assimilates to grain yield: Its relationship with yield in
Argentnian sunflower cultivars released between 1930 to 1995. Filed Crop. Res. 105:88-96.
Maddonni GA, Chelle M, Drouet JL, Andrieu B. 2001. light interception of contrasting leaf azimuth canopies under square and rectangular plant
spatial distributions: simulations and crop measurements. Field crops Research: 70, 1-13.
Maddonni GA, Otegui ME, Cirilo AG. 2001. Plant population density, row spacing and hybrid effects on maize canopy architecture and light
attenuation. Field crops Research, 71:183-193.
Rahmati H. 2009. Effect of plant density and nitrogen rates on yield and nitrogen efficiency of grain corn. World Applied Science Journal,
7(8):958-961.
Sangio L, Gracietti MA, Rampazzo C, Bianchetti P. 2002. Response of brazilian maize hybrids from different ears to changes in plant
population. Field crops Research, 79:39-51.
Sangoi L. 2000. Understanding plant density effects on maize growth and development: an important issue maximizes grain yield. Field crops
Research, V. 21(1): 159-168.
Sarlangue T, Andrade FH, Calvino PA, Purcell LC. 2007. Why do maize hybrids respond differently to variation in plant density? Agronomy
Journal, 99: 984-991.
Schussler JR, Westage ME.1994. Increasing assimilate reserves doesn’t prevent kernel abortion at low water potential in maize. . Crop. Sci. 34:
1569-1576.
Timl AD, Setter A, Brian S, Konian J. 2001. Loss of kernel set due to water deficit and shade in maize: Carbohydrate supplies. Abscisic asid,
and Cytokinin. Crop. Science, 41: 1530-1540.
Tokatlidis IS, Has A, melidis V, Has I, mylonas I, evgenidis G, Copandean A, Ninou E, Fasoula VA. 2011. Maize hybrids less dependent on high
plant densities improve resource use efficiency in rained and irrigated conditions. Field crops Research, 120: 345-351.
Tokatlidis IS, Koutroubas SD. 2004. Areview study of maize hybrids dependence on high plant populations and its implications on crop yield
stability. Field crops Reserch, 88: 103-114.
Tokatlidis IS. 2001. The effect of improved potential yield per plant on crop yield potential and optimum plant density in maize hybrids. Journal
AgricultureScience,137: 299-305.
Tollenear M, Lee EA. 2002. Yield potential, yield stability and stress tolerance in maize. Field crops Reserch, 75: 161-169.
Tollenear M. 1999. Response of dry matter of corn accumulation in photosynthesis. Crop. Science, 19: 1275- 1279.
Turget I, Duman A, Bligili U, Acikgoz E. 2005. Alternate row spacing and plant density effects and dry matter yield of corn hybrids. Agronomy
and Crop Science, 191:146-151.
114