An Investigation into the Impact of Varying Fertilizer Doses on the Quality of Lettuce Seedlings

The present study was conducted with the objective of ascertaining the effects of varying doses of chemical fertilizer on the quality of seedlings from different lettuce cultivars (Ice Palace and Maritima). To this end, four doses (0, 0.6, 1.2 and 1.8 dS m-1) of a commercial chemical fertilizer (N-P-K) were applied by adjusting different electrical conductivity (EC) values. The variables measured included seedling height, stem diameter, leaf area, stem dry weight, leaf dry weight, Dickson Quality Index (DQI), leaf chlorophyll content, photosynthetic rate, stomatal conductance and leaf color (L*, Chroma and Hue). According to the results obtained, significant effects of fertilizer dose treatments on seedling quality were determined (p<0.05). When the main effects were analyzed, the highest stem diameter (1.58 mm), leaf area (6.68 cm2), stem dry weight (0.063 g), leaf dry weight (0.050), Dickson quality index (0.021), leaf chlorophyll content (7.69 CCI), photosynthesis rate (17.23 µmol m-2s-1) and stomatal conductance (417.8 mmol m-2s-1) values were obtained from 1.8 dS m-1 fertilizer dose application. Consequently, the enhancement in EC values resulting from fertilizer dose applications exhibited a substantial positive impact on seedling quality.