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אסיף מאגר המחקר החקלאי
פותח על ידי קלירמאש פתרונות בע"מ -
Phosphorus nutrition and the rhizosphere pH in Leucadendron 'Safari sunset'
Year:
2001
Source of publication :
Acta Horticulturae
Authors :
בן-יעקב, יעקב
;
.
זילבר, אבנר
;
.
מצ'ניק, בוריס
;
.
Volume :
545
Co-Authors:
Silber, A., Institute of Soils, Water and Environmental Sciences, Agricultural Research Organization, Volcani Center, Bet Dagan, 50250, Israel
Mitchnick, B., Department of Ornamental Horticulture, Agricultural Research Organization, Volcani Center, Bet Dagan, 50250, Israel
Ben-Jaacov, J., Department of Ornamental Horticulture, Agricultural Research Organization, Volcani Center, Bet Dagan, 50250, Israel
Facilitators :
From page:
135
To page:
143
(
Total pages:
9
)
Abstract:
The objectives of the three projects described here were to study the responses of Leucadendron 'Safari Sunset' plants to the phosphorus concentration in the irrigation solution, and to the rhizosphere pH. In a screen-house experiment (Exp. I) it was found that increasing the irrigation-P concentration to 20 mg/L significantly increased the leaf-P concentration, and improved the yield of plants grown in pots filled with tuff (volcanic material). The same trend was observed in an open-field experiment (Exp. II). A significant regression was found between the yields of plants grown in tuff-filled holes in a native soil and the irrigation-P concentration. Maximum yield was achieved when the irrigation-P concentration was 13-14 mg/L. An additional relationship was found between the yield and the leaf-P concentration. The P concentration required for maximum yield was calculated to be 3.4 g/kg dry weight. These results indicate that L. 'Safari Sunset' is not susceptible to normal P application. The fertilization management (mainly the amount of NH4 ions added through the irrigation water) affected the rhizosphere pH in this experiment: at high NH4 application the pH declined below pH 5, while at low NH4 application, the pH rose above 7. Impairment of plant growth at low pH may result from H+ toxicity or from the release of high concentrations of Al and Mn from the substrate. At pH above 7, plant growth was restricted by low availability of micronutrient. Despite the use of chelates, leaf-Fe, -Zn and -Mn concentration were lower than those in plants grown at lower pHs, which may indicate that inadequate acquisition of metals limited the development of the low-NH4-fed plants. The conclusion that the rhizosphere pH may be the most important factor affecting the development of L. 'Safari Sunset' plants is supported by the results of an experiment conducted in hydroponics systems: plants grown in aero-hydroponics system (Exp. III) at pH 5.5 developed normally, while those at pH 7.5 did poorly. Root development of plants grown at pH 7.5 was restricted, resulting in inhibited development of root hair, poor branching and root death. Whether pH affects plant development directly through physiological mechanisms that influence root hair formation, or indirectly through nutrient availability mechanisms is not clear.
Note:
Related Files :
Fertilization
NH4:NO3 ratio
Proteaceae
עוד תגיות
תוכן קשור
More details
DOI :
Article number:
Affiliations:
Database:
סקופוס
Publication Type:
מאמר מתוך כינוס
;
.
Language:
אנגלית
Editors' remarks:
ID:
29444
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:46
Scientific Publication
Phosphorus nutrition and the rhizosphere pH in Leucadendron 'Safari sunset'
545
Silber, A., Institute of Soils, Water and Environmental Sciences, Agricultural Research Organization, Volcani Center, Bet Dagan, 50250, Israel
Mitchnick, B., Department of Ornamental Horticulture, Agricultural Research Organization, Volcani Center, Bet Dagan, 50250, Israel
Ben-Jaacov, J., Department of Ornamental Horticulture, Agricultural Research Organization, Volcani Center, Bet Dagan, 50250, Israel
Phosphorus nutrition and the rhizosphere pH in Leucadendron 'Safari sunset'
The objectives of the three projects described here were to study the responses of Leucadendron 'Safari Sunset' plants to the phosphorus concentration in the irrigation solution, and to the rhizosphere pH. In a screen-house experiment (Exp. I) it was found that increasing the irrigation-P concentration to 20 mg/L significantly increased the leaf-P concentration, and improved the yield of plants grown in pots filled with tuff (volcanic material). The same trend was observed in an open-field experiment (Exp. II). A significant regression was found between the yields of plants grown in tuff-filled holes in a native soil and the irrigation-P concentration. Maximum yield was achieved when the irrigation-P concentration was 13-14 mg/L. An additional relationship was found between the yield and the leaf-P concentration. The P concentration required for maximum yield was calculated to be 3.4 g/kg dry weight. These results indicate that L. 'Safari Sunset' is not susceptible to normal P application. The fertilization management (mainly the amount of NH4 ions added through the irrigation water) affected the rhizosphere pH in this experiment: at high NH4 application the pH declined below pH 5, while at low NH4 application, the pH rose above 7. Impairment of plant growth at low pH may result from H+ toxicity or from the release of high concentrations of Al and Mn from the substrate. At pH above 7, plant growth was restricted by low availability of micronutrient. Despite the use of chelates, leaf-Fe, -Zn and -Mn concentration were lower than those in plants grown at lower pHs, which may indicate that inadequate acquisition of metals limited the development of the low-NH4-fed plants. The conclusion that the rhizosphere pH may be the most important factor affecting the development of L. 'Safari Sunset' plants is supported by the results of an experiment conducted in hydroponics systems: plants grown in aero-hydroponics system (Exp. III) at pH 5.5 developed normally, while those at pH 7.5 did poorly. Root development of plants grown at pH 7.5 was restricted, resulting in inhibited development of root hair, poor branching and root death. Whether pH affects plant development directly through physiological mechanisms that influence root hair formation, or indirectly through nutrient availability mechanisms is not clear.
Scientific Publication
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