The experiment was conducted at the Research Field under the Department of Agricultural Botany, Patuakhali Science and Technology University (PSTU), Dumki, Patuakhali during the period from July 2013 to December 2013 to judgment out the most productive genotypes on the aspect of morpho–physiological, yield and yield attributing traits of T. Aman Aromatic rice genotypes.The seeds of five T Aman Aromatic rice genotypes were used as planting materials which were collected from various sources such as the Farmers of the different villages of Patuakhali, Branch office of Bangladesh Rice Research Institute (BRRI), Barisal and Bangladesh Rice Research Institute (BRRI), Joydebpur, Gazipur–1701. The selected five Aromatic T. Aman rice genotypes are
V1: Kataribhog
V2: Radhunipagal
V3: Kalizira
V4: Shakhorkhana
V5:
The experiment consisted of five rice varieties and was laid out in Randomized Completely Block Design (RCBD) with three replications. The size of plot was 4.0 × 2.5 m where block to block and plot to plot distance was 1.0 and 0.5 m, respectively. Row to row and plant to plant distance were also 20 and 20 cm, respectively, in each plot. So, the total plots were 15 (varieties 5 × replication 3).
Measurement of yield and yield contributing characters
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 total tillers per hill
Number of total tillers hill–1 were recorded from the following calculation
Number of total tillers= number of effective tillers + non effective tillers
Number of effective tillers per hill
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
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.
Leaf area index (LAI)
The leaf area of one hill was measured by an automatic leaf area meter. Leaf area of the rest five hills were calculated from the leaf dry weight of respective hills multiplying with the ratio of the leaf area of measured hills and its dry weight. Then the leaf area was expressed as average of five. Finally leaf area index (LAI) was calculated as follows–
Where, LA = leaf area (cm2), P = ground area (20 cm × 15 cm = 300 cm2 plant–1)
Total dry matter (TDM) weight
The plant parts such as leaves, stems, roots and panicles were detached and were kept separately in oven at 82O C for 72 hours. The oven dried samples were weighed for dry matter production. The total dry matter production was calculated from the summation of dry matter produced by leaves, stem, roots, panicles and weight of grain per plants in gram at different days after transplanting.
Crop growth rate (CGR)
The CGR value of crops were calculated for the period of 60–75 DAT and 75–90 DAT. Rate of dry matter production per unit of time per unit of ground area was calculated with the following formula:
Panicle length (cm)
Panicle length was measured by a meter scale from the basal node of the rachis to the apex of each panicle from the randomly selected 5 hills and their average was recorded and converted into cm.
Number of total grains per panicle
Number of total grains panicle–1 were recorded by the following formula
Number of total grains= Number of filled grains + number of unfilled grains
Number of filled grains per panicle
Filled grain was considered to be filled if any kernel was present there in. Number of filled grain was recorded from randomly selected 5 hills and converted into filled grains panicle–1.
Number of unfilled grain panicle
Number of unfilled grains panicle–1 means the absence of any kernel inside in and such grains present on each hill were counted from the randomly selected 5 hill.
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.
Biological yield (t ha–1)
Biological yield is the sum of grain and straw yield which was recorded into kg plot–1 and finally converted into t ha–1. The biological yield was calculated by using the following formula:
Biological yield= Grain yield + straw yield
Harvest index (%)
Harvest index is the ratio of the economic yield to the total biological yield of a crop. The harvest index was calculated by using the following formula:
Harvest index (%) =
Where, Economic yield = Grain yield
Biological yield = Grain yield + Straw yield
Statistical analyses
Data recorded for morpho–physiological, yield and yield contributing characters were compiled and tabulated in proper form for statistical analyses. Analysis of variance was done following the Randomized Complete Block Design with the help of MSTAT–C package programme developed by Russel (1986). The mean differences among the treatments were evaluated with DMRT test (Gomez and Gomez, 1984).
Chiniguri