Growth, yield components and yield of hybrid rice

Table 3. Effect of nitrogen level and time of homo-brassinolide application on dry matter accumulation (DMA) at different

stages of hybrid rice

DMA (gm -2 )

Treatments

20 DAT

40DAT

60DAT

80DAT

Nitrogen level (kg/ha)

N0*

109.3

198.9

366.2

497.0

N60

117.9

240.1

508.6

802.1

N120

133.7

267.8

559.7

843.8

N180

145.3

307.8

663.7

948.9

N240

153.6

346.2

757.1

1044.9

SEm(±)

2.5

4.6

5.3

3.9

CD(P=0.05)

7.2

13.3

15.3

11.3

Time of homo-brassinolides application

AT

129.9

255.6

499.0

754.6

AT+PI

131.3

279.5

578.1

833.4

AT+PI+FL

134.8

281.4

636.0

894.0

SEm(±)

1.9

3.6

4.1

3.1

CD(P=0.05)

NS

10.4

11.8

8.9

components like number of panicles m -2 , panicle

The results are in conformity with the findings of

length, number of spikelets and filled grains

Hu et al. , (2007) and Huang et al . (2008). Spraying

panicle -1 , percentage of filled grain and test weight

of homo-brassinolide showed significant effect on

increased steadily up to the application N ₁₈₀ and

all the yield components of hybrid rice. Spraying of

were comparable to N ₂₄₀ (Table 4). Both N ₁₈₀ and N 240

homo-brassinolide at AT+PI+FL and AT+PI recorded

recorded significantly higher number of panicles m -2 ,

significantly higher number of panicles m -2 , longer

longer panicle length, greater number of spikelets

panicle length, greater number of spikelets and filled

and filled grains panicle -1 , higher percentage of filled

grains panicle -1 , higher percentage of filled grain

grain and greater test weight than what obtained at

and greater test weight than what obtained at only

lower nitrogen levels (N ₁₂₀ , N ₆₀ and N 0 ). The crop at

one application of spraying of homo-brassinolide at

low nitrogen level (N ₀ ) produced the lowest values

active tillering stage. The crop at single application

of all the yield components, but was comparable to

of homo-brassinolide produced the lowest values

those obtained at N ₁₂₀ and N ₆₀ in most of the cases

of all the yield components. Similar type of results

during the study. The tropical rice hybrids are panicle

were reported by Sakamoto et al . (2006) and Bera and

size and require adequate nutrition like nitrogen

Pramanik (2012).

for producing higher number of large size panicles

(Buresh et al. , 2005). Application of lower dose of

Crop productivity

nitrogen (N ₆₀ and N ₀ ) did not mitigate the nutrient

The nitrogen level exerted significant effect on grain

need of the crop particularly during its reproductive

yield, straw yield and harvest index (HI) of hybrid

period resulting in lower number of spikelets and

rice. The highest grain yield (6116 kg ha -1 ) was

filled grains panicle -1 with low test weight due

produced in crop receiving N nitrogen level (180

180

to its adverse affect on grain filling of hybrid rice.

kg N ha -1 ); whereas, the highest straw yield (8170kg

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