MIM Akhand
Agronomy Division, BRRI, Gazipur
BC Roy
BRRI, Gazipur
JC Biswas
Agronomy Division, BRRI, Gazipur
N Parvin
RFS Division, BRRI, Gazipur
S Paul
FMPHT Division, BRRI, Gazipur
Urea solution spray, Growth stage, Rice yield, N dose
Bangladesh Rice Research Institute Farm, Gazipur
Crop-Soil-Water Management
We executed one observation and two replicated experiments at BRRI, during boro and aman seasons of 2009 to 2012 to address the objective of this study. One observational trial was done in same season with urea solution spraying and urea top dressed following conventional method. The treatments were: Urea at 266 kg ha-1 (BRRI recommended) as top dress in three splits, spraying 1.5% urea solution at 15, 30, 45 and 60 days after transplanting (DAT), top dressed 177 kg urea ha-1 in 2 splits at 15 and 30 DAT along with 2 split of urea solution spraying (1.5%) at 45 and 60 DAT, spraying 4.5 % urea solution at 15, 30, 45 and 60 DAT, top dressed 177 kg urea ha-1 in 2 splits at 15 and 30 DAT along with 2 splits of urea solution spraying (4.5%) at 45 and 60 DAT, top dressed 196 kg urea ha-1 in 4 splits at 15, 30, 45 and 60 DAT (same amount of urea as in 4.5% solution), top dressed 65 kg urea ha-1 in 4 splits at 15, 30, 45 and 60 DAT (same amount of urea as in 1.5% solution), 100 kg urea ha-1 (frequent spraying 1.5% urea solution), 243 kg urea ha- 1 (frequent spraying 4.5% urea solution), LCC based N through spraying and LCC based N through top dress, N- control. In subsequent seasons, trials were conducted with specific urea solution concentration. Lastly replicated field experiment was conducted with urea management both in aman and boro seasons. The N management options imposed were: Urea at 266 kg ha-1 in boro and 175 kg ha-1 in aman top dressed at 20, 30 DAT and at panicle initiation (PI) stage (T1), 2/3rd recommended N top dressed at 20, 30 DAT along with 3.5% urea spraying at PI stage (T2), 2/3rd recommended N, top dressed at 20, 30 DAT along with 3.5% urea spraying at PI and booting stages (T3), 2/3rd recommended N, top dressed at 20, 30 DAT along with 3.5% urea spraying at maximum tillering (MT), PI and booting stages (T4) and, N-control (T5). Urea spray volume was prepared by mixing 3.5 kg urea in 100 L of water as per treatments. This liquid was sprayed by knapsack sprayer at different dates. A blank dose of Phosphorus and Muriate of potash were applied at 13-42 kg PK ha-1 in aman and 23-47 kg PK ha-1 in boro seasons, respectively. The treatments were distributed in RCB design with 3 replications. In aman season, 2010, thirty two days’ old seedlings of BRRI dhan49 were transplanted at 20 x 20 cm spacing on 2 August. In the following year was repeated with same aged of seeding was planted on 25 July, at 20 x 20 cm spacing. The trial was also repeated in boro season, 2011, planted with forty days-old seedlings of BRRI dhan45 on 8 January. Similarly, this trial was again repeated in the following boro season in 2012. Forty three days-old seedlings of BRRI dhan29 was planted on 19 January, at 20 x 20 cm spacing. Insects and weeds were controlled as and when necessary. Data on panicle number, grains panicle-1, sterility (%), grain yield and straw yield were recorded during harvesting. The collected data were analyzed following by MSTAT program and means were compared by DMRT at 5% level of probability.
Eco-friendly Agril. J. 6(09): 188- 192, 2013 (September); ISSN 1999-7957
Journal