| Abstract: | Abstract The influence of method of drying on concentrations of total P, extractable phosphate and two N fractions in petioles from recently matured sugarbeet leaves was studied. Method of drying had no or small effects on total P, total N and nitrate‐N. However, method of drying had a marked effect on the value of extractable phosphate. Concentrations of phosphate‐P extractable with water and 2% acetic acid were least with freeze‐dried material and increased as temperature of oven drying was varied from 70 to 100°C. Extractable phosphate‐P in tissue dried by a particular method was lower when acetic acid was the extractant. Quantity of extract‐able phosphate‐P in oven‐dried material was not influenced by substitution of ascorbic acid for stannous chloride and elimination of the H2O2 oxidation step in the analytical procedure. Leaf position greatly affected concentrations of total P and acetic‐acid soluble phosphate‐P. Both parameters at a given sampling date decreased with increasing age of leaf. |
