Effect
Basfoliar Kelp SL treated Lettuce, var. Crispa, grown in a hydroponic floating system had on average a 20 % higher plant height, a non-significant higher stem diameter (+6.8 %), a 87.2 % higher total fresh weight with a 31.4 % higher leaf fresh weight, a 21.9 % higher stem fresh weight, a 22.2 % higher root fresh weight, a non-significant 6.8 % higher shoot/root ratio, a 22.7 % higher total dry weight with a 24.7 % higher leaf dry weight, a 2.9 % higher stem dry weight, a 22.1 % higher root dry weight and a 2.1 % higher dry shoot/root ratio, a 29.9 % higher yield, a 31.1 % higher fresh cut leaves yield, a 21.4 % higher WUE and 22.9 % higher NUE (significant for all the doses), 9,3 % more leaves (only significant for highest dose), a 38.2 % higher leaf area, a 40.3 % higher stomatal conductace, 4.8 % more ascorbic acid (not significant), and 11,3 % less NO3- compared to the untreated lettuce. In general there can be stated that the 4 mL/L dose had the biggest significant effect, the effect of the lowest dose was most of the time not significant. The 1 mL/L dose had the best effect on the post-harvest weight loss and NO3- content of lettuce.
