EFFECTS OF SUPPLEMENTARY POTASSIUM AND PHOSPHORUS ON PHYSIOLOGICAL DEVELOPMENT AND MINERAL NUTRITION OF CUCUMBER AND PEPPER CULTIVARS GROWN AT HIGH SALINITY (NaCl)

• Published in: Journal of plant nutrition Vol. 24; no. 9; pp. 1457 - 1471
• Main Authors: Kaya, Cengiz, Kirnak, Halil, Higgs, David
• Format: Journal Article
• Language: English
• Published: Philadelphia, NJ Taylor & Francis Group 30-09-2001; Taylor & Francis
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Deficiencies. Phytotoxicity of elements. Salinity; Economic plant physiology; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Mineral nutrition; Nutrition. Photosynthesis. Respiration. Metabolism; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Nutrient solution; Environmental factor; Inorganic element; Mineral fertilization; Dicotyledones; Hydroponic cultivation; Angiospermae; Development; Capsicum annuum; Solanaceae; Supplementation; Macronutrient(mineral); Laboratory study; Experimental physiology; Nutrition; Cucurbitaceae; Phosphorus; Cucumis sativus; Ecophysiology; Sodium chloride; Stress; Salinity; Vegetable crop; Spermatophyta; Soil plant relation; Mineral salt; Potassium; Cultivar
• ISSN: 0190-4167; 1532-4087
• DOI: 10.1081/PLN-100106995

Two cucumber (Cucumis sativus) cultivars, Seraset F
1
and Rabina F
1
, and two pepper (Capsicum annuum) cultivars, California Wonder and Charliston 52, were grown hydroponically for six weeks to investigate the effectiveness of supplementary potassium (K) and phosphorus (P) applied to the root zone of plants grown at high (60 mM) NaCl concentration. Treatments used in this experiment were (i) control: nutrient solution alone, (ii) high salt: nutrient solution plus 60 mM NaCl, and (iii) high salt with supplementary P and K: nutrient solution plus 60 mM NaCl, 1 mM KH
2
PO
4
, and 2 mM K
2
SO
4
. Supplementary 1 mM KH
2
PO
4
and 2 mM K
2
SO
4
was added to nutrient solution for four weeks. Plants grown at high salt produced less dry matter and chlorophyll than those in normal nutrient solution for both cucumber and pepper cultivars. Reductions in both dry matter and chlorophyll concentrations were greater for pepper than cucumber. Supplementary K and P restored dry matter and chlorophyll concentrations for both species to levels similar to the control. Membrane permeability increased with high salt application and these increases were greater for pepper. Supplementary K and P restored membrane permeability in both species to levels similar to the control. Plant daily water use was decreased by high salt but it was restored with supplementary K and P to levels similar to the control. Sodium (Na) concentration in plant tissues increased for both species in the high salt treatment. Concentrations of P and K were in the deficient range in the plants grown at high salt and supplementary K and P application corrected these deficiencies.