Phosphorus determination in rice plants containing variable manganese content by the phospho‐molybdo‐vanadate (yellow) and phosphomolybdate (blue) colorimetric methods uri icon

abstract

  • Phosphorus (P) determination by the phosphomolybdate-blue (Mo-blue) and phosphomolybdate-vanadate-yellow (vandate-yellow) color methods using NH4OH to neutralize excessive acidity were unaffected by increasing manganese (Mn) content in standard P solutions and rice plant acid digests. The vanadate-yellow color method using sodum hydroxide (NaOH) to neutralize excessive acidity over estimated P when the Mn content exceeded 0. 16 mug/Mn/mL in the final dilution of standard P solution and 247 mug Mn/g in rice plant tissue. Phosphorus determination by the vanadate-yellow color method using ammonium hydroxide (NH4OH) was linearily related with P estimated by the Mo-blue color and vanadate-yellow color methods using NaOH for acid neutralization. Phosphorus estimated by the vanadate-yellow color method using NH4OH could be calculated from the a regression between both methods of neutralizing the excessive acidity.

publication date

  • 1993
  • 1993