Effects of Proline and Seaweed on Growth Parametres and of Green Onion Cultivation under Greenhouse Conditions

This study was conducted to investigate the effects of proline (PR), an amino acid, andseaweed (SW), which has biostimulant properties, on the growth and development ofgreen onion (Allium cepa L.) plants. The experiment was conducted in an unheated glassgreenhouse at Van Yüzüncü Yıl University using a randomized block experimentaldesign. Key growth parameters including plant height, root length, stem diameter, numberof leaves, total fresh and dry weight, and SPAD value were assessed. The results revealedthat the highest plant height (29.24 cm) was recorded in the PR2+ SW1 (100 ppm proline+ 3 g/L seaweed) treatment, demonstrating a significant synergistic effect compared toindividual applications (p &lt; 0.001). The longest root length was observed in the PR1+SW2 (50 ppm proline + 5 g/L seaweed) treatment (17.02 cm), suggesting enhanced rootdevelopment. The highest stem diameter (5.40 mm) was measured in the SW2 (5 g/Lseaweed) treatment. Regarding biomass accumulation, the PR1+ SW2 treatment resultedin the highest total fresh weight (172.67 g), while the control group had the lowest (144.00g). The highest dry weight (22.91 g) was recorded in the PR2+ SW1 treatment. Forchlorophyll content, the PR2+ SW1 treatment yielded the highest SPAD value (69.53),though the differences were not statistically significant (p = 0.1467). These findingssuggest that proline and seaweed applications can enhance growth and yield in greenonion production, with the PR2+ SW1 combination providing the most favorable results.However, further studies are needed to determine the optimal application rates, assesstheir effectiveness under different environmental conditions, and evaluate their long-termimpact on agricultural production.<br>