LaMotte AST Series Professional Soil Test Outfits - Manual (Page 39)

PLANT TISSUE PROCEDURE
Follow the test procedures for nitrate nitrogen, phosphorus and
potassium, using tissue extract instead of soil extract. Results should be
used in a comparative manner, which can be used with the lists below to
determine relative concentrations. The most meaningful test results will
be obtained by comparing healthy plants to problem plants.
Guidelines for Interpreting Plant Tissue Tests
Test Factor Test Reaction
Relative Amount Of
Nutrient In Plant Tissue
Nitrate Nitrogen Dark Pink Color Abundant
Light Pink Color Adequate
Colorless No Reserve/Probably Deficient
Phosphorus Deep Blue Color Adequate
Light Blue Color Adequate
Yellow to Colorless Low to Deficient
Potassium Heavy Precipitate Adequate to Abundant
Medium Precipitate Low to Deficient
Trace Precipitate Deficient
No Precipitate Very Deficient
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