Rafidain Journal of Science

Abstract

The current study was conducted during the period from April 2021 to August 2021 on Zinnia elegans L. Its flowers are purple in color to study the effect of pinching of the growing tip of the plant or without, and spray twice the shoot system with paclobutrazol at concentrations (0, 15 and 30) mg. L^-1 and ascorbic acid at concentrations (0, 150 and 300) mg. L^{-1, in the qualities of vegetable growth,} The factorial experiment was implemented using Randomized Complete Block Design within Split Plot, with three replicates and seven plants for the experimental unit. The results indicated the following: The pinching of the growing top of the plant led to a delayed the date of flowering, increased inflorescences longevity and increased morally in the content of anthocynin in flowers40.58 mg.100g^-1 wet weight. The spraying of paclobutrazol at a concentration of 30 mg. L^-1 delayed the date of flowering and increased inflorescences longevity, while spraying in both concentrations 15 and 30 mg. L^-1 increased the number of flowers to 2.09 and 2.32 flower. per plant, respectively. Ascorbic acid spraying delayed the date of the flowering and led to spraying at a concentration of 300 mg. L^-1 and increased inflorescences longevity, and significantly increased the content of anthocynin in inflorescences to 51.23 mg.100g^-1 wet weight.