Afrina Rahman
Department of Agronomy, Bangladesh Agricultural University, Mymensingh - 2202, Bangladesh
Md. Abdus Salam
Department of Agronomy, Bangladesh Agricultural University, Mymensingh - 2202, Bangladesh
Md. Abdul Kader
Department of Agronomy, Bangladesh Agricultural University, Mymensingh - 2202, Bangladesh
Md. Shafiqul Islam
Department of Agronomy, Bangladesh Agricultural University, Mymensingh - 2202, Bangladesh
Suriaya Perveen
Department of Agronomy, Bangladesh Agricultural University, Mymensingh - 2202, BANGLADESH
Boro rice, Crop establishment methods, Growth, Variety, Yield
Agronomy Field Laboratory, Bangladesh Agricultural University (BAU), Mymensingh.
Crop-Soil-Water Management
The research work was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University (BAU), Mymensingh. The experimental field belongs to the non-calcareous dark grey floodplain soil under the Agro- ecological Zone of the Old Brahmaputra Floodplain (AEZ-9) (FAO and UNDP, 1988) located at 24.75° N latitude and 90.50°E longitude at an elevation of 18 m above the sea level. The field was a medium high land with flat and well drained condition with the pH value of the soil ranged from 5.9-6.5. The experiment consists of two factors; factor A: methods of crop establishment viz., dry direct seeding, unpuddle transplanting, AWD (alternate wetting and drying) and puddle transplanting; factor B: rice cultivars viz., BRRI dhan28, BRRI dhan58, BRRI dhan74 and BRRI hybrid dhan3. The experiment was laid out in a split-plot design with three replications where method of crop establishment was assigned to the main plot and rice cultivar was assigned to the sub plots. Thus total number of plot was 48. Each plot size was 4 m × 2.5 m. The distance between block to block was 1.0 m, the distance between replica- tion to replication was 1.5 m and that of plot to plot distance was 0.75 m. A piece of land was selected at Agronomy Field Laboratory, BAU, Mymensingh to raise seedlings. The sprouted seeds were sown in the nursery bed on 22 November 2017 for puddle trans- planting, unpuddle transplanting and AWD methods. The main field was prepared by power tiller with three to four times ploughing and cross ploughing followed by laddering. After laying out the land was fertilized with urea, Muriate of Potash (MoP), triple super phosphate, gypsum and zinc sulphate @ 300- 100-120-60-10 kg ha-1, respectively (FRG, 2012). The entire amounts of TSP, MoP, gypsum and zinc sulphate were applied at the time of final land preparation. Urea was applied in three equal installments at 15, 30 and 45 days after transplanting. The seedlings were uprooted and immediately transferred to the main field for puddle transplanting, unpuddle transplanting and AWD methods and for dry direct seeding method sprouted seeds were sown in the main field manually on 30 December 2017. Seedlings were transplanted at the rate of two seedlings hill-1, maintaining a spacing of 25 cm × 15 cm. Weed was removed when necessary. Irrigation were given in the plots as per treatment specification e.g. dry direct seeding, alternate wetting drying, unpuddle transplanting as well as puddle trans- planting required only 7, 10, 15 and 15 irrigations, respectively. When 80-90% of the panicles turned into golden yellow color, the crop was assessed to attain maturity. The crops of puddle transplanting, unpuddle transplanting and AWD plots were harvested on 1 May 2018 at 160 DAS and dry direct seeding plots on 30 May 2018 at 151 DAS. Five hills (excluding border hills) were selected randomly from each unit plot for recording data. Data were collected on different growth dynamics, such as leaf area index (LAI), total dry matter (TDM) production (g), absolute growth rate (AGR), crop growth rate (CGR), relative growth rate (RGR), net assimi- lation rate (NAR) at different growth stages. The data were recorded for each pot through destructive sampling. For each destructive sample, a hill was uprooted and washed with water. The leaf blades were alienated from the leaf sheath and leaf area was measured by a leaf area meter (LI 3100, Licor, Inc., Lincoln NE, USA). Leaf area index was accordingly calculated from leaf area data. After measurement of leaf area, the plant samples were dried in an electric oven for 72 hour until they reached at
Archives of Agriculture and Environmental Science 5(2): 137-143 (2020)
Journal