The experiment was conducted at Patuakhali Science and Technology University (PSTU), Dumki, Patuakhali during the period from July 2012 to December 2012 to investigate the performance of some modern rice varieties and seedling number hill–1 under tidal ecosystem of Bangladesh.
Experimental materials
The seeds of six modern Aman rice varieties were used as planting materials.
3.2.1 Variety, source of collection and treatments
The seeds of rice varieties were collected from the Farmers of the different villages of Patuakhali, Bangladesh Rice Research Institute (BRRI), Joydebpur, Gazipur–1701 and Bangladesh Institute of Nuclear Agriculture (BINA), Mymensingh. Treatments were as follows:
Factor A: Variety (V)
V1 : BR 11
V2 : BR 23
V3 : BRRI dhan40
V4 : BRRI dhan44
V5 : BINA dhan7
V6 : BRRI dhan52
Factor B: Seedling number hill–1
S1 : 3 seedlings hill–1
S2 : 5 seedlings hill–1
S3 : 7 seedlings hill–1
So, the treatments combinations are as follows
V1× S1 : BR 11 × 3 seedlings hill–1
V1× S2 : BR 11 × 5 seedlings hill–1
V1× S3 : BR 11 × 7 seedlings hill–1
V2× S1 : BR 23 × 3 seedlings hill–1
V2× S2 : BR 23 × 5 seedlings hill–1
V2× S3 : BR 23 × 7 seedlings hill–1
V3× S1 : BRRI dhan40 × 3 seedlings hill–1
V3× S2 : BRRI dhan40 × 5 seedlings hill–1
V3× S3 : BRRI dhan40 × 7 seedlings hill–1
V4× S1 : BRRI dhan44 × 3 seedlings hill–1
V4× S2 : BRRI dhan44 × 5 seedlings hill–1
V4× S3 : BRRI dhan44 × 7 seedlings hill–1
V5× S1 : BINA dhan7 × 3 seedlings hill–1
V5× S2 : BINA dhan7 × 5 seedlings hill–1
V5× S3 : BINA dhan7 × 7 seedlings hill–1
V6× S1 : BRRI dhan52 × 3 seedlings hill–1
V6× S2 : BRRI dhan52 × 5 seedlings hill–1
V6× S3 : BRRI dhan52 × 7 seedlings hill–1
Parameters studied
- Seedling height and dry matter before transplanting
- Plant height (cm)
- Number of total tillers hill–1
- Number of effective tiller hill–1
- Number of non effective tiller hill–1
- Number of grain panicle–1
- Number of sterile spikelets panicle–1
- Length of panicle (cm)
- 1000 seed weight (g)
- Grain yield (t ha–1)
Straw yield (t ha–1)
Measurement of morpho–physiological parameters
Seedling height (cm) and dry matter before transplanting
Seedling height was recorded before transplanting from ten randomly selected plants from each variety. The seedling height was considered from ground level to the tip of the leaf by a measuring scale and converted into cm. The sampled plants were oven dryied at 70 0C until the constant weight was obtained for recording dry weight.
Plant height (cm)
The effective plant height was considered from ground level to the tip of the leaf at vegetative phase and panicle at harvest stage. Plant height data was measured by a meter scale and converted into cm.
Number of effective tillers hill–1
The panicles which had at least one grain was considered as effective tiller. The number of effective tillers of 5 hills was recorded and expressed as effective tillers number hill–1.
Number of non–effective tillers hill–1
The tiller having no panicle was regarded as ineffective tiller. The number of ineffective tillers 5 hills–1 was recorded and was expressed as non–effective tiller number hill–1.
Number of spikelets hill–1
Spikelet was considered to be filled if any kernel was present there in. Number of spikelet was recorded from randomly selected 5 hills and converted into spikelets hill–1.
Number of spikelets panicle–1
Recorded spikelets hill–1 was converted into spikelets panicle–1 by the following formula: total spikelets hill–1 / number of total panicle hill–1
Number of sterile spikelets hill–1
Sterile spikelets means the absence of any kernel inside in and such spikelets present on each hill were counted from the randomly selected 5 hill.
Number of sterile spikelets panicle–1
Recording sterile grains hill–1 data converted into sterile grains panicle–1 by the following formula: total sterile grains hill–1 / number of total panicle hill–1
Panicle length (cm)
Panicle length was measured from the basal node of the rachis to the apex of each panicle from the randomly selected 5 hills.
1000–grain weight (g)
One thousand cleaned dried seeds were counted randomly from each sample and weighed by using a digital electric balance at the stage the grain retained 12% moisture and the mean weight were expressed in gram.
Grain yield (t ha–1)
Grain yield was determined from the whole plot and expressed as t ha–1 on 12% moisture basis. Grain moisture content was measured by using a digital moisture tester.
Straw yield (t ha–1)
Straw yield was determined from the whole plot. After threshing, the sub–sample was oven dried to a constant weight and finally converted to t ha–1.