| Autor: |
Taber, Henry G., Lawson, Vince |
| Předmět: |
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| Zdroj: |
Communications in Soil Science & Plant Analysis; 2007, Vol. 38 Issue 5/6, p713-718, 6p, 4 Graphs |
| Abstrakt: |
Tomato petiole sap from potassium (K) rate experiments conducted on prairie loam and river coarse sand soils from 1998 to 2002 was used to measure K concentration via the battery-operated portable Cardy flat membrane electrode meter and inductive coupled plasma (ICP) laboratory instrumentation. In 1998, for undiluted sap levels less than 3000 mg kg-1 the linear Cardy-ICP correlation was r=0.94, but when K was more than 3000 mg kg-1, r was only 0.53. Diluting the sap with water (1:1) improved the linear range to 6000 mg K L-1 (r=0.87, n=190). Petiole sap K, measured by either Cardy or ICP, was highly correlated to whole-leaf K concentration all years, r=0.8 to 0.91. Even through the slope of the regression lines were similar for the years, the intercepts were significantly different (P<0.01). The Cardy electrode can be reliably used for tomato petiole K determination provided the sap is diluted and the usual handling precautions are taken to prevent petiole moisture loss and maintain stability in electrode readings. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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