Response of Lettuce Plant ( Paris Island Cos cv.) to Humic Acid and Seaweed Extract Alga – 300 Spray


Abstract: An experiment was carried out to study the effect of foliar spray of hamic acid with three concentrations ( 0 , 1 and 2 ml.L-1 ) and three concentrations of seaweed extract – Alga 300 ( 0 , 1.5 and 2.5 ml. L-1 )and their interactions to improve vegetative growth and yield of lettuce plants ( Paris Island Cos cv ).All treatment applied three times separately at 15/2 the first spray then repeated every two week . Results revealed that the treatments led to improve vegetative growth traits and total yield of lettuce as compared with control . The more effect interaction treatment was between ( 2ml/L. of hamic acid + 2.5 ml/L Alga 300 ) gave a significant increase in most vegetative traits and yield , which giving yield of 9651 Kg./Donum as compared with 8427 Kg./ Donum for control treatment . Analysis of correlation indicated that a significant positive correlations between the total yield of lettuce with the head weight , stem weight , stem length and number of leaves/ plant . The higher correlation ( 0.999 ) was recorded from the head weight the total yield . On the other hand , head weight exhibited a greatest direct effect on the total yield as comparing with the other traits , and this character had a higher indirect effects through the path of number of leaves/ plants , stem length , stem weight and head circumference . So they can be used in the breeding programs to select the total yield of lettuce .