EFFECTS OF PHOSPHORUS AND POTASSIUM ON THE GROWTH AND YIELD OF STEM AMARANTH (Amaranthus oleraceus)

Abstract

An experiment was conducted at the Central Farm of Sher-e-Bangla Agricultural University, Dhaka during the period of April to June, 2005 to study the effects of four levels of phosphorus (P20s) viz., control treatment (no phosphorus), P1 (43.2 kg/ha), P2 (48 kg /ha) and P3 (52.8 kg /ha) and four levels of potassium (K20) viz., control treatment (no potassium), K1 (114 kg /ha), K2 (120 kg/ha) and K3 (126kg/ha) on the growth and yield of stem amaranth. The two factor experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. Most of the growth and yield parameters were significantly influenced by both phosphorus and potassium at 45 DAS. The maximum plant height (87.99 cm), plant diameter (2.43 cm), green yield per plant (285.54 g) and green yield per hectare (45.70t) were observed in the treatment of phosphorus applied al 48 kg/ha at 45 DAS. The minimum plant height (78.17 cm), plant diameter (l .50 cm), green yield per plant (187.27 g) and green yield per hectare (30.00t) were obtained from the control treatment at 45 DAS. The maximum plant height (87.49 cm), plant diameter (2.70 cm), green yield per plant (285.00g) and green yield per hectare (45.60t) were found from the plot receiving 120 kg K/ha at 45 DAS, while the control treatment gave the lowest plant height (78.51 cm), plant diameter ( 1.52 cm), green yield per plant (189. I Sg) and green yield per hectare (30.30t). Among the treatment combinations P2K2 ( 48kg P + 120 kg K/ha) gave the highest plant height (92.47cm), plant diameter (3.00 cm}, green yield per plant (326.40g) and green yield per hectare (52.22t) at 45 DAS. The lowest plant height (48.47 cm}, plant diameter ( 1.50 cm), green yield per plant (187.14g) and green yield per hectare (29.94t) were recorded from the control treatment.