Growth and flowering response of zinnia plant to spraying with tryptophan and chelated zinc

Zinnia elegans development and flowering parameters were studied in relation to two separate foliar treatments with tryptophan acid and chelated zinc. The study had a factorial design treatments, including different concentrations of tryptophan acid (0, 10, 20 and 30 mg/L) and chelated zinc (0, 20, 40 and 60 mg/L). The treatments were applied in a factorial experiment with two factors and three replications and the experiment was implemented using a completely randomized block design (R.C.B.D) 4×4×3 = 48. were analyzed using analysis of variance (ANOVA) and comparisons were made. according to the Least Significant Difference test (L.S.D) at a probability level (0.05). the results showed that soil treated with 60 mg L-1 tryptophan acid and with chelated zinc at 100 mg. L-1 resulted in higher values of increase in dry weight, leaf content of total chlorophyll, leaf content of total soluble carbohydrates, and leaf content of nitrogen, number of pink flowers andflower Diameter. the interaction was 60 mg.L-1 tryptophan acid and 100 mg.L-1 chelated zinc, which did not differ from the interaction of humic acid at the same concentration with 50 mg.L-1 chelated zinc. the mentioned interaction treatments differed significantly from the individual treatments and was also significantly different from the control treatment in all the studied parameters.