Growth, yield components and yield of hybrid rice
Results and Discussion
1). It appeared that hybrid rice required high rate of
nitrogen application for better growth of the crop as
Growth attributes
reflected by its tillering and plant height. An increase
Plant height at all the growth stages and tillering
in plant height and tiller number in rice due to N
increased steadily due to increasing level of nitrogen
application have also been reported by a number of
application during the study. The result showed that
workers earlier and recently by Navin kumar et al .
the height of the rice plant increased progressively
(1996), Padmavathi (1997) and Peng et al. (2006).
up to 80 days after transplanting (DAT) when it
Time of homo-brassinolide (HBR) spraying had
attained about 97.3 - 107.2 cm height. The tallest
significant influence on plant height and tiller
plantsandhighestnumberoftillersm -2 wererecorded
production. Increasing number of homo-brassinolide
in crop receiving 240 kg N (N 240 ), but was comparable
spraying steadily increased plant height at all the
to those of its immediate lower (N 180 ) level (180 kg
growth stages and number of tillers m -2 (Table 1). The
N ha -1 ). Both the above nitrogen levels produced
tallest plants and highest number of tillers m -2 were
significantlytallerplantsandgreaternumberoftillers
produced at thrice spraying of homo-brassinolide
m -2 than those recorded at lower nitrogen level (N 0 ).
at active tillering (AT) + panicle initiation (PI) +
At low nitrogen (N 0 ) level produced the dwarf most
flowering (FL) stages and were significantly greater
plants at all the growth stages and lowest number of
than what obtained at only spraying at active tillering
tillers m -2 among all other nitrogen treatments (Table
(AT) stage. The dwarf most plants at different stages
Table 1. Plant height (cm) and tillers m -2 of hybrid rice at different growth stages as influenced by nitrogen and time of
homo-brassinolide application
Plant height (cm) Tillers m -2
Treatment
20DAT
40DAT
60DAT
80DAT
60 DAT
Nitrogen levels(kg/ha)
N 0 *
54.58
73.11
86.66
97.30
379.4
N 60
61.86
77.03
95.89
102.09
397.5
N 120
63.59
77.54
96.61
103.32
412.7
N 180
65.80
80.49
99.49
105.69
453.0
N 240
67.40
82.60
100.72
107.24
476.6
SEm( ± )
1.17
0.89
0.97
0.99
8.5
CD(P=0.05)
3.39
2.58
2.81
2.87
24.6
Time of homo-brassinolide application
AT
63.41
78.92
95.36
102.00
389.1
AT+PI
60.96
76.21
94.63
103.19
424.1
AT+PI+FL
63.56
79.34
97.63
104.19
458.3
SEm(±)
0.90
0.69
0.75
0.77
6.6
CD(P=0.05)
NS
2.00
2.17
NS
19.1
*N 0 = 0 kg N/ha (control), N 60 = 60 kg N/ha, N 120
= 120 kg N/ha, N 180
= 180 kg N/ha, N 240
= 240 kg N/ha); AT = Active tillering,
AT+PI= Active tillering + Panicle initiation and AT+PI+FL= Active tillering + Panicle initiation + Flowering).
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