Two field trials were conducted at Baramoon Experimental Farm, Dakahlia
Governorate, Egypt, during the winter seasons of 2004/2005 and 2005/2006 to study
the effect of foliar spray of salicylic acid (SA) at rates of 0, 50 and 100 ppm and
mixtures of some micronutrients (Fe + Mn + Zn) i.e., 120 ppm Fe + 60 ppm Mn + 60
ppm Zr., 240 ppm Fe + 120 ppm Mn + 120 ppm Zn and untreated plants as well as
their interaction on leafy yield, quality and chemical composition of lettuce cv. Balady.
Lettuce plants were sprayed two times at 30 and 45 days after transplanting. The sub
plots were devoted to the mixtures of some micronutrients. The obtained results
indicated that, spraying SA increased ali studied traits, except N03 accumulation that
was significantly decreased. The best results were obtained at 100 ppm SA treatment
in both seasons. For micrcnutrients treatments, foliar application of 240 ppm Fe + 120
ppm Mn + 120 ppm Zn was the most favorable treatment for yield, quality and
chemical composition of lettuce. The interaction between the experimental factors had
significant effects on all studied traits in both seasons. Foliar treatmert of 100 ppm SA
with 240 ppm Fe + 120 ppm Mn + 120 ppm Zn was optimal to lettuce leafy yield and
quality, especially, reducing nitrate accumulation in leaves, consequently, minimizing
the harmful effects on human health.