Spinach quality: Reduction of oxalate content in leaves through different phosphorus levels in the nutrient solution. Effect on growth parameters

摘要

The objective of this study was to compare the effect of different phosphorus levels in the nutrient solution (0, 1 and 3 me l(-1)) on spinach oxalate content and its effect on growth parameters. Fresh and dry weight, dry matter percentage, leaf number, petiole length, absolute growth rate, colour and oxalic acid content in leaves were measured. The highest fresh weight was found in the treatment without additional phosphorus in the nutrient solution at harvest. Dry weight increased from transplanting to harvest in an inverse manner with additional phosphorus in the nutrient solution. Phosphorus level had a significant effect on plant architecture. Spinach grown without additional phosphorous was more compact and had more leaves at harvest. In addition, an inverse relationship between leaf number and length of petioles was observed. At harvest the highest level of oxalic acid content was in treatment with additional phosphorus in the nutrient solution.