Effects of Potassium and Proline Applications on Growth and Stress Tolerance of Cucumber (Cucumis sativus L.) Seedlings under Salt Stress Conditions
DOI:
https://doi.org/10.24925/turjaf.v14i5.1299-1304.8585Keywords:
Cucumber (Cucumis sativus L.), Potassium, Proline, Salt stress, Stress toleranceAbstract
This study aimed to determine the effects of different doses of potassium (KNO₃) and proline applied to cucumber (Cucumis sativus L.) seedlings under salt stress on morphological development, biomass accumulation, and physiological characteristics. The experiment was conducted in a randomized plot design in the Climate Chamber of Van Yüzüncü Yıl University Gevaş Vocational School, with a total of 480 plants, comprising four replications per treatment and 15 plants per replication. Salt stress was induced using a 100 mM NaCl solution, while potassium and proline treatments were applied foliarly twice a week. Parameters such as plant height, root length, stem diameter, number of leaves, fresh and dry weight, SPAD value, and leaf area were measured and analyzed. The results revealed that salt stress significantly reduced seedling growth and development. However, the combined application of 2000 ppm potassium nitrate and 2 mM proline (KNO3-2+Pr2) notably improved key parameters such as stem diameter (3.26 mm), root length (26.90 cm) and SPAD value (34.70). In addition, the highest leaf area value was observed under the KNO3-1 (1000 ppm KNO₃) treatment (31.34 cm²), On the other hand, the highest dose combination (KNO3-2+Pr2) exhibited limited effects on leaf area and dry weight, highlighting the importance of dosage sensitivity. Overall, the findings demonstrated that salt stress inhibits plant growth, yet potassium and proline treatments can positively influence parameters such as plant height, root length, number of leaves, leaf area, and chlorophyll content (SPAD). These results suggest that potassium and proline have potential to enhance salt stress tolerance and support the growth of cucumber seedlings under saline conditions.
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