A field experiment was conducted in Sher-e-Bangla Agricultural University (SAU), Dhaka, Bangladesh during the period from November, 2017 to March, 2018 in rabi season to observe the effect of biochar on the yield and quality of potato tuber and to find out the optimum dose of biochar along with inorganic fertilizer for achieving the maximum yield of potato. The experiment consist of 9 treatments as Control (no chemical fertilizer and biochar), Recommended Fertilizer Dose; Recommended Fertilizer Dose+Biochar @ 2.5 t ha-1; Recommended Fertilizer Dose+Biochar @ 5.0 t ha-1; Recommended Fertilizer Dose+Biochar @ 7.5 t ha-1; 1/2 of Recommended Fertilizer Dose+Biochar @ 2.5 t ha-1; ½ of Recommended Fertilizer Dose+Biochar @ 5.0 t ha-1; ½ of Recommended Fertilizer Dose + Biochar @ 7.5 t ha-1; Biochar @ 10 t ha-1. The experiment was laid out in a Randomized Complete Block Design with three replications. The tested variety was BARI Alu-7 (Diamant). Data were collected on different yield attributes, growth and quality of potato and postharvest soil analysis. The results indicated that biochar application significantly (p<0.05) increased plant height, weight of tubers, yield of tubers, tuber dry matter content, tuber specific gravity, soil organic carbon. Results suggested that biochar application had significant positive effect on plant and soil.

The experiment was conducted in the farm area of Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka during the period of July to November, 2015 to find out the effect of plant growth regulator-flora on the growth and yield of transplanted aman rice (BR 11-Mukta). The experiment comprised of 8 treatments as- T0: Control condition (No chemical fertilizer, no Flora), T1: Recommended Fertilizer Doses-RFD (120, 20, 80, 16 and 2 kg ha-1 of N, P, K, S and Zn, respectively), T2: RFD+1 time spray of Flora, T3: RFD+2 times spray of Flora, T4: ½ RFD+1 time spray of Flora, T5: ½ RFD+2 times spray of Flora, T6: No chemical fertilizer+1 time spray of Flora and T7: No chemical fertilizer+2 times spray of Flora. Data on different yield contributing characters, yield, and characteristics of post-harvest soil was recorded and significant variation was observed for different treatments. At harvest, the tallest plant (117.60 cm) was recorded from T3, while the shortest plant (88.85 cm) in T0 treatment. The highest number of filled grains panicle-1 (86.27) was recorded in T3, whereas the lowest number (68.53) in T0 treatment. The highest grain yield (5.13 t ha-1) was recorded in T3, while the lowest (2.78 t ha-1) in T0 treatment. The highest total nitrogen (0.632%) was recorded from T3, while the lowest (0.369%) in T0 treatment.