Effect of Humic Acid, Gibberellin and Tryptophan on The Growth and Flowering Characteristics of Goldenrods Plant Tolidago Canadensis

Abstract

The experiment was conducted in high school of Al-Hilla agricultural for the summer and autumn season 2020 to study the effect of humic acid and foliar application of gibberellin and tryptophan acid on the growth of the goldenrods plant resulting from the cultivation of solidago candasis which took it from residues of plant seeds growing. However, the first factor was humic acid, plants treated with humic acid were (H0 control, H1=5 ml/L), the second factor was the foliar application of gibberellin acid with the two levels (G1=100 mg/liter, G2=200 mg/L) and third factor was tryptophan acid with two three levels (T0=without treated, T1=100 mg/L, T2=150 mg/L). The experiment was conducted as a factorial experiment (2×3×3) with split-plot design according to the randomized complete blocks design (R.C.B.D) with three replicates. The results showed that humic acid fertilization improved the studied characteristics of the goldenrods plant. While treatment with gibberellin acid at concentration of 100 mg/liter due to improve the number of branches, leaf area and the number of inflorescences and the percentage of carbohydrates, whereas, treatment with concentration of 200 mg/liter leds to improve of plant height, length of inflorescence and vase life. As for the treatment with tryptophan acid, the concentration 150 mg/L improved all the studied parameters.