EFFECT OF WEEDING AND UREA SUPER GRANULE APPLICATION ON THE GROWTH AND YIELD OF BORO RICE CV. BRRI dhan45

Abstract

An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during the period from December 2008 to May 2009 with a view to find out the effect of weeding and Urea Super Granules (USG) fertilizer on the yield and yield characters of Boro rice BRRI dhan45. There were two sets of treatments; a) three weedings viz., no weeding, one weeding and two weeding and b) five levels of USG viz., control (no USG), one, two, three and four pellet (s) of USG per 4 hills, respectively. The experiment was laid out in a randomized complete block design with three replications. Grain and straw yields were the highest (4.00 and 5.78 t ha-1 , respectively) in two weedings. The lowest grain yield of 3.44 t ha-1 was obtained from no weeding. Level of USG significantly influenced all the plant characters, except; plant height, panicle length and weight of 1000-grain. Grain and straw yields were found the highest (4.44 and 5.89 t ha-1 , respectively) from the level of 4 pellets of USG per 4 hills. The interaction effect of weeding and level of USG had significant influence on all the crop characters under study, except plant height, panicle length and weight of 1000-grain. The finding of the study suggested that two weedings in combination with 4 pellets of USG per 4 hills gave the highest grain yield of 4.90 t ha-1 of the boro rice variety BRRI dhan45.

Full text

Bangladesh J. Nuclear Agric. 30: 67-74, 2014
EFFECT OF WEEDING AND UREA SUPER GRANULE
APPLICATION ON THE GROWTH AND YIELD OF
BORO RICE CV. BRRI dhan45
M. E. Hossain1, M. A. Ullah2, A. R. Gazi3, M. A. Kader4
Abstract
An experiment was conducted at the Agronomy Field Laboratory, Bangladesh
Agricultural University, Mymensingh during the period from December 2008 to May
2009 with a view to find out the effect of weeding and Urea Super Granules (USG)
fertilizer on the yield and yield characters of Boro rice BRRI dhan45. There were two
sets of treatments; a) three weedings viz., no weeding, one weeding and two weeding
and b) five levels of USG viz., control (no USG), one, two, three and four pellet (s)
of USG per 4 hills, respectively. The experiment was laid out in a randomized
complete block design with three replications. Grain and straw yields were the
highest (4.00 and 5.78 t ha-1, respectively) in two weedings. The lowest grain yield of
3.44 t ha-1 was obtained from no weeding. Level of USG significantly influenced all
the plant characters, except; plant height, panicle length and weight of 1000-grain.
Grain and straw yields were found the highest (4.44 and 5.89 t ha-1, respectively)
from the level of 4 pellets of USG per 4 hills. The interaction effect of weeding and
level of USG had significant influence on all the crop characters under study, except
plant height, panicle length and weight of 1000-grain. The finding of the study
suggested that two weedings in combination with 4 pellets of USG per 4 hills gave
the highest grain yield of 4.90 t ha-1 of the boro rice variety BRRI dhan45.
Key words: Boro rice (BRRI dhan45), Urea Super Granule (USG), Weeding.
Introduction
Rice (Oryza sativa L.) is the major food crop of Bangladesh. The area and
production of rice in Bangladesh are about 10.37 million hectares and 25.16 million
tons, respectively with an average yield of only 2.43 t ha-1. Among the groups,
transplanted Aman (T. Aman) rice covers about 50.92% of total rice area and
contributes to 39.03% of total rice production in the country (Anonymous, 2009). The
possibility of horizontal expansion of rice production area has come to a standstill
(Hamid, 1991).
1Soil Science Division, Bangladesh Institute of Nuclear Agriculture, BAU Campus, Mymensingh-2202, Bangladesh
2Plant Breeding Division, Bangladesh Institute of Nuclear Agriculture, BAU Campus, Mymensingh-2202, Bangladesh
3TCP Division, Bangladesh Institute of Nuclear Agriculture, BAU Campus, Mymensingh-2202, Bangladesh
4Department of Agronomy, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh

Effect of weeding and urea super granule on boro rice
68
Weeds compete with rice plants severely for space, nutrients, air, water and
light; and adversely affect plant height, leaf architecture, tillering habit, shading
ability, growth pattern and crop duration (Miah et al., 1990). The rice crops infested
heavily with weeds can reduce the grain yields by 68-100% for direct seedbed Aus
rice, 16-48% for Aman rice and 22% for modern Boro rice (Anonymous, 1998).
According to Smith and Shaw (1999), weed depresses the normal yield of grains
panicle-1 and grain weight. Yield loss depends upon some variables like magnitude of
weed infestation, type of weed species and duration of weed associated with crop
(Moody, 1998).
Nitrogen use efficiency for rice crop ranges between 25 and 35%, and seldom
exceeds 50% (Singh and Yadav, 1985). The condition of wet land soil promotes N
losses through ammonia volatilization, leaching and surface runoff when it is applied
as prilled form in the soil surface. Urea super granules (USG) is a fertilizer that can be
applied in the rice root zone at 8-10 cm depth of soil (reduced zone of rice soil) which
can save 30% nitrogen compared to prilled urea (Savant et al., 1991). According to
Crasswell and De Datta (1980), broadcast application of urea on the surface soil causes
losses up to 50% but deep placement of USG in point may result in negligible loss. The
savings of applied N reached 70 and 35 kg ha-1 when applied USG as N fertilizer during
the Boro and Aman seasons, respectively (Bowen et al., 2005). Therefore, the aim of the
study was to find suitable weed management practices and USG application on the
growth and yield of boro rice.
Materials and Methods
The experiment was conducted at the Agronomy Field laboratory, Bangladesh
Agricultural University, Mymensingh during the period from December 2008 to May
2009. The experimental area belongs to Sonatala soil series under Old Brahmaputra
Flood plain (AEZ-9). The experimental field belongs to Non-calcareous Dark Grey
Floodplain Soil. The field was a medium high land of silty loam soils having pH around
6.5. Two sets of treatments were imposed as; Factor A: weeding – 3: no weeding (W0),
one weeding (W1) and two weedings (W2) and Factor B: level of urea super granules
(USG) – 5: control (No pellet of USG) ≈ 0 kg N ha-1 (N0), one pellet of USG (1.8 g) per
4 hills ≈ 30 kg N ha-1 (N1), two pellets of USG (3.6 g) per 4 hills ≈ 60 kg N ha-1 (N2),
three pellets of USG (5.4 g) per 4 hills ≈ 90 kg N ha-1 (N3) and four pellets of USG
(7.2g) per 4 hills ≈ 120 kg N ha-1 (N4). The experiment was laid out in a randomized
complete block design with three replications. Total number of unit plots were 45 (3 × 5
× 3). Spaces between blocks and unit plots were 1 m and 0.5 m, respectively. The size of
unit plot was 10 m2 (4.0 m × 2.5 m). The seeds started sprouting after 48 hours and

Hossain et al. /Bangladesh J. Nuclear Agric. 30: 67-74, 2014
69
became suitable for sowing in 72 hours. The nursery bed was made wet by application
of water one day ahead of uprooting the seedlings. Thirty-one days old seedlings were
uprooted carefully without causing any mechanical injury to the root. The seedlings
were then transplanted on first January 2009 in the well puddled plots.
The plots were fertilized with 100, 75, 60 and 10 kg ha-1 of triple super
phosphate, muriate of potash, gypsum and zinc sulphate, respectively at the time of final
land preparation (Anonymous, 2004). As per experimental specification one, two, three
or four pellet (s) of USG were placed manually at a depth of 6-8 cm at the centre of four
hills of two adjacent rows at five days after transplanting.
Three seedlings were transplanted in each hill with a spacing of 25 cm × 15 cm.
Seedlings in some hills died off and those were replaced by gap filling after one week of
transplanting with seedlings from the same source. Weeding was done as per treatment.
During weeding, different weed species grown in the experimental filed were identified.
A constant level of standing water up to 5 cm was kept in early growth stage in the
experimental field to enhance tillering and the water level was increased to some extent
to discourage late tillering. The field was finally drained out before 15 days of harvest to
enhance maturity. No remarkable infestation of insect or infection of disease was noticed
in the field. Therefore, no plant protection measure was taken.
Five hills (excluding border hills) from each plot were randomly selected,
uprooted and properly tagged before harvesting for recording of necessary data. The
crop was harvested at full maturity when 90% of the grains turned golden yellow in
colour. Grains were sun dried to a moisture content of about 14% and then weighed.
Straw was also sun dried and weighed. Yields of both grain and straw were converted to
t ha-1. The following data were recorded: Plant height (cm), number of effective tillers
hill-1, panicle length (cm), number of grains panicle-1, 1000-grain weight (g), grain yield
(t ha-1), straw yield (t ha-1), biological yield (t ha-1) and harvest index (%). Data on
individual plant parameters were recorded from five randomly selected hills of each plot
and those on grain yield, straw yield, biological yield and harvest index were recorded
from the whole plot at harvest. The collected data were analyzed using the analysis of
variance (ANOVA) technique and the significance of the mean differences were
adjudged by Duncan’s Multiple Range Test (Gomez and Gomez, 1984).

Effect of weeding and urea super granule on boro rice
70
Results and Discussion
Effect of weeding
The effect of weeding on plant height (cm), panicle length (cm) and weight of
1000-grain did not show any significant difference (Table 1). On the other hand,
number of effective tillers hill-1, number of grains panicle-1, grain yield (t ha-1), straw
yield (t ha-1), biological yield (t ha-1) and harvest index (%) showed significant
difference (Table 1).
Pplant height (75.37 cm), number of effective tillers hill-1 (18.05), panicle
length (19.29 cm), number of grains panicle-1 (62.7), weight of 1000-grain (27.72g),
grain yield (4.00 t ha-1), straw yield (5.78 t ha-1), biological yield (9.77 t ha-1) and
harvest index (43.09%) obtained from two weedings showed insignificant difference
(Table 1)
Effect of USG levels
The highest plant height (75.47cm) was obtained from application of 1 pellets of
USG per 4 hills. Number of effective tillers hill-1 (17.16), panicle length (19.63 cm),
number of grains panicle-1 (61.98), weight of 1000-grain (27.86 g), grain yield (4.44
t ha-1), straw yield (5.89 t ha-1) and biological yield (10.33 t ha-1) was obtained from
the application of 4 pellets of USG per 4 hills. In case of 4 pellets of USG per 4 hills,
number of effective tillers hill-1 was obtained 16.97 cm. Harvest index of 43.03%,
42.19% and 42.24% were recorded in 4, 3 and 2 pellets of USG per 4 hills, respectively.
Table 1. Effect of weeding on yield and plant characters of Boro rice cv. BRRI dhan45
Weeding
Plant
height
(cm)
Effective
tillers hill-1
(no.)
Panicle
length
(cm)
Grains
Panicle-1
(no.)
1000
grain wt.
(g)
Grain
yield
(t ha-1)
Straw
Yield
(t ha-1)
Biological
yield
(t ha-1)
Harvest
index
(%)
W0
73.29
12.46c
19.29
46.42c
27.72
3.44b
4.74b
8.18b
41.81b
W1
74.31
13.83b
19.25
53.91b
27.42
3.48b
4.60b
8.08b
43.09a
W2
75.37
18.05a
19.39
62.74a
27.61
4.00a
5.78a
9.77a
40.79b
S

1.06
0.20
0.16
0.50
0.22
0.04
0.05
0.06
0.40
CV (%)
4.41
5.14
4.14
5.65
3.15
5.77
7.47
5.67
4.53
Weeding: W0 = No weeding (Control), W1 = One weeding, W2 = Two weeding
In a column, means followed by common letter(s) do not differ significantly at 5% level by DMRT.

Hossain et al. /Bangladesh J. Nuclear Agric. 30: 67-74, 2014
71
The lowest plant height (72.85cm) was obtained by the application of 3 pellets
of USG per 4 hills. Number of effective tillers hill-1 (13.66cm), panicle length (19.03
cm) and number of grains panicle-1 (43.51) was obtained from the application of 1, 2
and no pellets of USG per 4 hills. In case of 2 pellets of USG per 4 hills, weight of
1000-grain (27.24g) was obtained. Grain yield (2.84 t ha-1), straw yield (4.04 t ha-1),
biological yield (6.87 t ha-1), harvest index (40.74%) was obtained from application
of no pellets of USG per 4 hills (Table 2).
Table 2. Effect of USG levels on yield and plant characters of Boro rice cv. BRRI dhan45
USG
Levels
Plant
height
(cm)
Effective
tillers
hill-1
(no.)
Panicle
length
(cm)
Grains
panicle-1
(no.)
1000
grain
wt.
(g)
Grain
yield
(t ha-1)
Straw
yield
(t ha-1)
Biological
yield
(t ha-1)
Harvest
index
(%)
N0
74.85
11.46d
19.63
43.51d
27.86
2.84e
4.04d
6.87e
41.28b
N1
75.47
13.66c
19.57
48.22c
27.67
3.31d
4.84c
8.15d
40.74b
N2
73.96
14.66b
19.03
56.34b
27.24
3.64c
5.01c
8.66c
42.24ab
N3
72.85
16.97a
19.10
61.76a
27.55
3.95b
5.43b
9.38b
42.19ab
N4
74.48
17.16a
19.22
61.98a
27.60
4.44a
5.89a
10.33a
43.03a
S

1.37
0.26
0.21
0.65
0.29
0.05
0.07
0.08
0.52
CV (%)
4.41
5.14
4.14
5.65
10.01
5.77
7.47
5.67
4.53
Levels of USG: N0= No USG (Control), N1= 1.8 g hill-1, N2=3.6 g hill-1, N3=5.4 g hill-1, N4=7.20 g hill-1
In a column, means followed by common letter(s) do not differ significantly at 5% level by DMRT.
Interaction effect of USG and weeding
Plant height, panicle length, 1000-grain weight did not differ significantly due
to the interaction between levels of USG and weeding but number of effective tillers
hill-1, number of grains panicle-1, grain yield (t ha-1), straw yield (t ha-1), biological
yield (t ha-1) and harvest index (%) differed significantly (Table 3).
In case of plant height, the tallest plant (77.29 cm) was obtained in the
interaction between two weedings and one pellet of USG per 4 hills and the lowest
(69.86 cm) was obtained in the interaction between two weedings and three pellets of
USG per 4 hills (Table 3). In case of effective tiller hill-1, the highest number of
effective tiller hill-1 (21.14) was obtained from the interaction between two weedings
at 15 and 30 DAT and four pellets of USG per 4 hills, which was statistically identical
with two weedings and three pellets of USG per 4 hills. The lowest number of
effective tiller hill-1 (10. 47) was obtained from no weeding and no application of
USG. The interaction did not show any significant effect on panicle length (Table 3).

Effect of weeding and urea super granule on boro rice
72
Table 3. Interaction effect of weeding and level of USG on yield and plant characters of Boro
rice cv. BRRI dhan45
Treatments
Plant
height
(cm)
Effective
tillers hill-1
(no.)
Panicle
length
(cm)
Grains
Panicle-1
(no.)
1000
grain wt.
(g)
Grain
yield
(t ha-1)
Straw
yield
(t ha-1)
Biological
yield
(t ha-1)
Harvest
index
(%)
W0N0
73.43
10.47e
19.24
37.35i
27.95
2.63h
4.09g
6.72h
39.11d
W0N1
74.89
12.96d
19.65
42.74h
27.34
3.13g
4.66f
7.79fg
40.22bcd
W0N2
73.37
11.33e
18.75
48.54g
27.07
3.41ef
4.63f
8.04f
42.42abc
W0N3
69.86
13.83d
19.10
53.70de
28.63
3.81cd
5.05e
8.86e
42.98ab
W0N4
74.89
13.72d
19.69
49.78fg
27.61
4.20b
5.28de
9.48cd
44.31a
W1N0
76.65
10.57e
19.76
41.14h
27.82
2.55h
3.38h
5.93i
42.94ab
W1N1
74.24
12.75d
19.11
48.03g
28.34
3.19fg
4.37fg
7.56g
42.29abc
W1N2
74.50
13.26d
18.85
56.35d
27.22
3.62de
4.55f
8.17f
44.31a
W1N3
72.93
16.13c
19.39
61.71c
26.55
3.85cd
5.11e
8.96e
42.93ab
W1N4
73.22
16.63c
19.13
62.33c
27.20
4.21b
5.58cd
9.79c
42.99ab
W2N0
74.45
13.53d
19.90
52.03ef
27.82
3.33fg
4.63f
7.96fg
41.81a-d
W2N1
77.29
15.27c
19.96
53.88de
27.32
3.62de
5.49d
9.11de
39.71cd
W2N2
74.00
19.37b
19.48
64.11c
27.43
3.90c
5.85bc
9.75c
39.99bcd
W2N3
75.75
20.93a
18.82
69.86b
27.47
4.20b
6.12b
10.32b
40.66bcd
W2N4
75.35
21.14a
18.82
73.83a
28.00
4.90a
6.83a
11.73a
41.80a-d
S

2.37
0.46
0.36
1.12
0.50
0.09
0.11
0.14
0.90
CV (%)
4.41
5.14
4.14
5.65
10.01
5.77
7.47
5.67
4.53
Weeding: W0 = No weeding (Control), W1 = One weeding, W2 = Two weedings
Levels of USG: N0 = No USG (Control), N1 = 1.8 g hill-1, N2 = 3.6 g hill-1, N3 = 5.4 g hill-1, N4=7.20 g hill-1
In a column, means followed by common letter(s) do not differ significantly at 5% level by DMRT.
The highest grains panicle-1 (73.83) was found in the interaction between two
weedings and 4 pellets of USG per 4 hills. The lowest number of grains panicle-1
(37.35) was found in the interaction between no weeding and no USG application
(Table 3). In case of straw yield, the highest straw yield (6.83 t ha-1) was found in the
interaction between two weedings and 4 pellets of USG per 4 hills. The lowest straw
yield (4.09 t ha-1) was obtained from the interaction between no weeding and no USG
application (Table 3). In case of grain yield, it was observed that the highest grain
yield (4.90 t ha-1) was obtained from two weedings which was followed by the grain
yield under the interaction of two weedings at 15 and 30 DAT and 4 pellets of USG
per 4 hills. The lowest grain yield (2.55 t ha-1) was obtained from the interaction
between no weeding and no USG application (Table 3). In case of biological yield, it
was observed that the highest biological yield (11.73 t ha-1) was obtained from the
interaction between two weedings and 4 pellets of USG per 4 hills. The lowest

Hossain et al. /Bangladesh J. Nuclear Agric. 30: 67-74, 2014
73
biological yield (6.72 t ha-1) was obtained from the interaction between no weeding
and no USG application (Table 3). In case of harvest index, it was observed that the
highest harvest index (43.31%) was obtained from the interaction between no weeding
and 4 pellets of USG per 4 hills which was statistically similar to the interaction
between one weeding and 2 pellets of USG per 4 hills. The lowest harvest index
(39.11%) was obtained from the interaction between no weeding and no USG
application (Table 3).
Conclusion
From the experimental results, it elucidated that two weedings and application
of four pellets of USG per 4 hills performed the best in respect of grain yield of the
boro rice variety BRRI dhan45. Hence, two weedings and 4 pellets of USG weighting
7.2 g of each pellet by placing them in the center of four hills of two adjacent rows
with the spacing of 25 cm × 15 cm could be suggested for higher yield of Boro rice
variety BRRI dhan45.
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