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Plant Part: Youngest mature leaf
Sampling Procedure: Collect leaves from at least 20 to 25 plants. Starting from the middle of the whorl, work outward to select a leaf to sample. Select the youngest, fully-expanded leaf .
| Analysis | Tissue Concentration Guidelines | ||||||||
| Low/Marginal Range | Sufficiency Range | Excessive, toxic? | |||||||
| Nitrogen, % N | 3.90 | - | 4.30 | 4.30 | - | 5.50 | |||
| Phosphorus, %P | 0.37 | - | 0.45 | 0.45 | - | 1.10 | |||
| Potassium, % K | 1.00 | - | 1.50 | 1.50 | - | 4.00 | |||
| Calcium, % Ca | 0.40 | - | 0.50 | 0.50 | - | 1.50 | |||
| Magnesium, % Mg | 0.20 | - | 0.25 | 0.25 | - | 1.00 | |||
| Sulfur, % S | 0.20 | - | 0.25 | 0.25 | - | 0.80 | |||
| Zinc, ppm Zn | 7 | - | 10 | 10 | - | 50 | |||
| Iron, ppm Fe | 30 | - | 50 | 50 | - | 250 | 500 | - | 800 |
| Manganese, ppm Mn | 15 | - | 25 | 25 | - | 250 | |||
| Copper ppm Cu | 3 | - | 5 | 5 | - | 20 | |||
| Boron, ppm B | 20 | - | 30 | 30 | - | 100 | |||
| Nitrogen-to-sulfur ratio (N:S) | 5 | - | 8 | 8 | - | 15 | |||
| Sodium, % Na | - | - | |||||||
| Chloride, % Cl | - | - | |||||||
