Effects of salinity and additional calcium on rabbiteye blueberry Vaccinium ashei Reade /
| Main Author: | |
|---|---|
| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1991.
|
| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Abstract: | Experiments were conducted to determine the physiological responses of rabbiteye and southern highbush blueberries to 0, 25 and 100 mM Na+ as Na2SO4 and NaCI, with and without added Ca2+ (1, 3 and 10 mM). Blueberries were sensitive to a high level (100 mM) of salinity, which caused growth depression of shoots and roots. Plant growth under 25 mM Na+ treatments was not as severely affected. Root growth was depressed more than shoot growth, regardless of the Na+ species applied. Supplemental Ca2+ did not ameliorate NaCI damage to shoots on any cultivar, possibly because of the inability of Ca2+ to counter the toxic effects of Cl-. Under moderate Na2SO4 treatment (12.5 mM), supplemental Ca2+ successfully ameliorated salinity damage by improving leaf growth. Under high Na2SO4 treatment (50 mM), 1 mM Ca2+ produced optimum leaf growth. High Na+ treatments also led to decreased stomatal conductance, photosynthesis and transpiration. NaCI salinity was more damaging to gas exchange than was Na2S04 salinity, presumably due to the additional effects of Cl-. Calcium supplements were often able to ameliorate the salinity damage, but Ca2+ was more beneficial when applied to plants treated with Na2SO4 than NaCI salinity. Leaf chlorophyll content was not greatly diminished by Na+ or improved by Ca2+. 'Sharpblue' was damaged more by NaCI salinity than was 'Tifblue'. Mineral nutrient concentrations in leaves, roots and stems indicated that a breakdown in the Na+ excluding mechanism was responsible for high leaf Na+ concentrations at 50 mM Na2SO4 and 100 mM NaCI salinity. Sodium chloride application led to higher leaf Na+ concentrations than did Na2SO4 possibly because of Na+ and/or Cl- disruption of metabolism. Calcium applications effectively lowered leaf Na+ concentration only when Na2S04 was the salt source. High Ca2+ also led to higher [22]Na+ uptake into leaves, possibly because of metabolic damage due to Ca2+. Sodium treatments also decreased leaf K+ and Ca2+ concentrations, but had little effect on leaf Fe. Leaf chlorosis in field-grown plants may be due to high bicarbonates. Acidification may aid in improving irrigation water to a quality suitable for blueberry growth if bicarbonates are a cause of concern. |
|---|---|
| Item Description: | Typescript (photocopy). Vita. "Major subject: Horticulture." |
| Physical Description: | xv, 185 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |